In the US, GFI's are only required on appliances which require them for safety, and as such, those appliances must be sold with a GFI built in. I am not sure the exact definition of things which require them, but I do know they are required on things that function in or near water above a very low amperage. The US and UK actually have very similar regulations, however, the point of failure are vastly different. The US regulates the appliances while the UK regulates the homes.
Richard Smith in the US GFCI's are required in wet locations, outside, bathroom, kitchen sink area, mud room, utility room, unfinished basement, pools. they are also required by OSHA on all job sites so there are a lot of extension cord type adapters for that purpose. we do have the option of going with a breaker or socket in applications. typical example would be a bathroom would have GFCI outlet, outdoor outlets would be strung to either a master GFCI breaker or a master homerun GFCI outlet. pool equipment would probably be on a GFCI breaker. temporary power drops are also required to have GFCI outlets because they're typically used for construction... OSHA requirement written into NEC. I have also started to see 240v equipment in fast food restaurants being put onto GFCI's. oh and then any equipment that would be used in a bathroom like hairdryers and curling irons ( I'm surprised we don't have them on toasters yet because that is an essential bathroom appliance LOL ). in some ways I like the idea in the UK that they have whole home protection, with the usual side effect of knocking out all the lights in the house.
AFCI, arc fault circuit interrupters are being required almost everywhere now (US). they originally started popping up about 3 years ago and were only required in bedrooms to prevent arcing when plugs were not plugged in all the way?, cords under carpets?, plugs jammed in wall behind bookcases?, Chinese "pink" electric blankets!. now they're being promoted as a way to prevent installation faults and the occasional siding nail through installed wire. however it was more of a "me company have patent, how do I get requirement in NEC!, and Get MO Money" and it has a mess of requirements on shared neutrals in 3-way (2-way? in the UK) switch boxes which can guarantee a house being retrofitted will guarantee a trip(s) and a subsequent lighting circuit(s) rewire.
I really like the transparent design of these safety devices. It enables you to directly see what the build quality is like. But I think a downside is the fact that it's pretty damn hard to read the ratings on the front.
you could also easily spot a fault (either manufacturing fault or fault after some time in operation). I think it's just for show / educational purposes and not actually installation. The transparent circuit breaker we had in our company had a lable on it: only for educational use. Maybe because the plastic wasn't up to swiss /european standards (i guess they should be fire resistant)
The ratings could be printed on an area with nothing to see, with a non transparent background. I like the idea of being able to see any internal skid marks or other damage. If they can make these in a way they won't become brittle and dangerous, they should make it part of the standards to require them... Old time fuse wire holders (at least in Australia) were easy to check for damage. Modern stuff is a pain and requires an electrician, which is expensive.
Yes, the usual unknowns, as with all Chinese 'safety' related devices from ebay are the longevity of the plastics used. Will they discolour? (Not so bad) Will they go brittle? (Could be bad). Are they flammable? (Could be very bad). That is one reason we have decent regulations in many countries. I am not saying this product is bad; it's just that we don't know. It's the stuff you can't see or isn't immediately apparent. The subtleties of these RCBOs is fantastic - do have a look at mikeselectricstuff if interested.
US suppliers _do_ make clear breakers, but usually they are strictly for R&D or education. Buddy at work had a few from Westinghouse. Very interesting, but those actually were code compliant and were flame retardant. The plastic was not a clear polystyrene or something like that one, but more of an off-color mostly translucent plastic. Still could see the guts working, tho.
Back in '64 I was "electrocuted" when a double adapter in my left hand broke apart. I was thrown back and my left hand gripped the exposed terminals tightly. My good friend had the sense to grab the cable and rip it from my hand and so saved my life. In a reenactment we figured it was about 10 to 15 seconds before I was "released" from the life sucking force. To me, it seemed like an eternity. I could hear and feel and see the individual cycles, which seemed to me to be at about 8hz to 10hz rather than 50hz. We were outdoors, on the back of a tip truck being setup as a makeshift stage for a concert. As I rocked back and forth on my back the trees above me shimmered in sync with the A/C and I felt like I was in an enormous centrifuge or washing machine. Still have a barely perceptible scar on my thumb from the burn. As you say, even 300mS would seem like a very long time because in a life threatening situation like this time really does slow down. After that, I purchased a portable ELCB and have always insisted that all band equipment pass through it.
stories like that are about dc lol ... ac rarely makes your muscles stiff like that for such a long period of time ?! Well at least thats what i learned as a paramedic 20 years ago...
I helped somebody (for free) that I normally did sound for ( and used to get paid for ) with an outdoor event that called for rain. thankfully there was no incident. however I was prepared ( a trait that I had before Boy Scouts ) and had everything on stage ran into the trailer (were all the wedge/mains amps and wifi mixer were set up) to the least populated closest to the door PDU so if disaster struck I was one switch away from killing all AC onstage about 10 feet away. later I remembered that I had put together a GFCI box that I wish I pulled out. unfortunately 3 bands in the owner of the equipment who really didn't want to be there called it and we started packing up. 10 min. after the trailer was packed the rain stopped. and I still had to drive an hour home soaking wet from helping with tents, tarps, setup and mixing. Having been at a church that did an outdoor picnic and always would have the worst weather for the entire year, I came fully prepared for this event and got no respect for my skill(s). having both sampled of 120V US 60 Hz and 240V 60 Hz Filipino I feel your pain. and no I will never forget my experience either, even if I was just unplugging a fan from an extension cord. ( I did not bring enough electrical tape with me! ).
@The1Rausch Perhaps you should return to paramedic school for a revision, your recall is opposite to the facts. AC causes tetanic contraction, DC does not.
Reminds me of the time I was far too casual and stupid, and got a hand-to-hand 240V shock to remind me to be more sensible in the future. Like you, I felt every pulse and they seemed to be around 5 Hz. Time obviously slowed down. Fortunately the shock was applied to the fingertip of one hand otherwise my fingers would probably have locked onto the conductor (AC tends to do that) and it was such that I could jerk away from it without help (which was very fortunate because I was on my own). Didn't last long. Maybe 10 pulses in all. No visual effects. Other than my underwear turning brown.
If standards people had half a clue they'd spec stuff like this to have transparent cases to make it easier to spot fakes. (Though I do wonder if it has the same fire rating).
Maybe a flame test to see if that clear plastic self extinguishes would do some good if it's tough enough plastic. Fakes are sociopathic if not just completely stupid so that easily overwhelms the notion that it might look like a toy to some... I almost want one of these for fun.
I'm not sure how you're defining "fakes." If it qualifies to the standards, how is it fake? If it's just a lower cost alternative to an expensive brand, it's not really best described as "counterfeit" or "fake."
Landrew0, if the relevant standard required that such devices have a transparent housing it would be more difficult for unscrupulous manufacturers to pass off under-spec or non-compliant devices as genuine, since a simple visual inspection would immediately reveal that the internal components are not up to scratch.
So, another instance of Chinese crap being not crappy. This was a very enlightening video, Clive. All of yours seem to be, but sometimes the subject item carries more impact for me. Thanks once again.
I'm not so sure. I'm not keen on the lack of thermal runaway protection on the MOV. Others are questioning of the clear plastic is sufficiently flame retardant.
Perhaps Clive will chime in to share if there is the recycling symbol for which clear material is being used for the body? Other than not having the Stamp of Approval, he seemed pleased/satisfied with the device.
Might not be necessary (depending on the thermal/magnetic breaker rating). If the MOV fails low-resistance, the current draw will trip the overcurrent breaker (which will provide the necessary safety factor). The fact that the breaker would then NOT reclose (fault not cleared) would indicate to the user that there's a persistent fault.
Two questions: Can circuit to the MOV will support the trip current without burning up? Those look like some small wires. Second: I was under the impression that failed MOV got hot. Very hot. That's what caused some power strips to catch fire.
Well worth buying just to play around with. As to the problem with rising saddle clamps - a pretty common installation fault here, and one that I've had to rectify may times. Best to give the conductors a tug just to make sure.
Combination MCB/RCD units are quite common in Australia. The double with ones are nice with their flags, but even the good brands leave out the flags in the smaller ones, making it hard to work out what tripped them. Apart from that, they are brilliant, isolating a fault to one segment of the house so other power circuits and lighting are unaffected.
Great post thanks! Very informative. LOL at your PDRC380 which my colleague designed. It's OK. We've had a few hanging round the office and the batteries have leaked which in my experience is due to small (but not zero) current drain. Maybe check yours from time to time. You're right the LCD is difficult to read. That's as much due to refraction in the plastic window as poor design - which was non-existent on this range. For its successor I suggested the product designer responsible for the enclosure also designed the LCD, and that worked well. There's no real difference in phase at x0.5; the AC test current is long enough for plenty of both polarity edges. For comparison, ramp tests use a dwell time of 300ms at each step. Type AC x1 limit is 300ms, x5 is 40ms (this corresponds to full mains voltage on the EN61010-1 accessible voltage graph). These days I would think a tightening of the x1 response is appropriate and that's what you see when testing. Only selective breakers go over 100ms. RCDs really are a godsend. I'm a bit doubtful about that MOV. I can see why they've got it - to prevent dV/dt SCR firing. But shouldn't it be downstream of the trip coil? Something so close to the supply will experience the worst of it and it's only a 10mm part. The 3K3 test resistor is too low for 230V operation IMHO. If you're interested in RCDs, have a look at Type A (pulsating DC ie half wave rectified) and then Type B (smooth DC ie electric car charging stations: yes we are going back to DC!)
+Mike Page I always remove the batteries from these units when not in use to protect against expensive leakage. I intend to test ordinary RCDs with various DC biased faults to see what type of circuitry defeats the protection. I'm guessing the proper pulses and DC fault versions are going to be quite complicated inside.
If you manage to saturate the CT without tripping you will indeed defeat the protection. That's how Robin Dlok worked. It was about 0.5A DC from memory, fairly quick ramp about 1-2s.
16:30 The resistor is likely calibration, yes. The diode is likely there to prevent "wrong direction" pulses doing bad to the SCR, probably unlatching it once triggered or such. The Capacitor will be parallel with the inductance of the core, likely to prevent any RFI getting at the SCR and randomly triggering it.
Well that circuit explains why one half wave takes longer.... It waits for the other half of the wave to trigger as it can only trigger in one direction. I guess most RCD's with a short half wave and a much longer half wave might use a similar concept.
OH i think you have answered my question i posted just now, it the "fault" were passing through a diode the feedback from the coil would always be out of phase getting clamped by the diode but it just "rings" inside the coil producing a smaller but still enough potential to trip it after a small delay. am i right?
If you look at the circuit, the diode on the gate of the SCR will short out (you will of course get the 0.6V Vf drop across the diode) any voltage that is positive on the Anode to the Cathode. The 0.6V VF is probably not going to trigger the SCR in this manner. On the NEXT half cycle The voltage across the diode will be Positive on the Cathode with respect to the Anode and this voltage will then trigger the SCR, tripping the RCD.
Agree with Clive that the larger physical size of the 2-part module may be less likely to allow an internal phase/neutral short compared with the narrow-bodied enclosure type. The case of the grey module is marked 4kA fault rated whereas the higher 6kA seems to be common in the uk.
240v tends to go with bang or in my case a pop when a mouse decided to chew through a positive and earth ring main cable it confused me at the start because we thought it was the fridge of the freezer that was tripping out as it was being very intermittent, eventually I was on the floor for over 15 minutes waiting for the damn thing to go pop and then I saw where the flash came from where the mouse had chewed it
I'm not a big fan of these combination breakers + RCD, as RCDs tend to fail much more often than breakers and I'd rather replace one device than two. And it's easier to bypass the RCD and still have overcurrent protection before I go and buy a replacement RCD (of course I mean at my own house). And for work I can just have 2 or three standard RCD values in the car and swap it on the go.
Lee x, did you find the mouse, probably up to ten feet/ three metres away? That happened with a friend's guinea pig when it chewed through the TV mains cable. The first they knew about it was when the power went off and most of a quivering guinea pig, minus front teeth, landed on the settee at the other side of the room. It didn't have the chance to do it again.
Note that the thyristor will only latch on for a half cycle. It shuts off on zero crossing. The 12K resistor is probably for noise suppression - just enough of a load to know it's a real imbalance and not some stray noise getting coupled into the circuit. Likewise for the cap - take care of high frequency noise.
I believe the 40ms trip comes from one half cycle of a heart beat as current passing through the heart for longer can make the heart go into fibrillation.
I've got one and modified it to use the test function to shut off power to everything on my workbench when a separate (emergency/safety) switch is pressed. One could also add a liquid level relay switch module to trigger the test circuit to shut off power when a certain liquid level is reached.
I wouldn't expect it to be such good quality with something as niche as this. Seems to be perfectly adequate to pass nearly any regulation. Would make a great educational tool for high schools. I am not sure how many have basic electrics classes in high school, i know I did.
Is my understanding correct, that the plastic casing has to flame retardant to some extent ? I don't think it's possible to make plastic transparent and flame retardant. The Chinese ones could be a fire risk if I'm correct.
*Doesn't "Made in China" already translate to:* "This is not to code." "This will not suppress an internal fire." "This will be a fire hazard." "This will void your home insurance." "Don't come a-knocking when this fails and burns your house down because we are a fly by night company and you won't get a cent from us."
not ''Made in China' per say(no doubt some reputable brands will manufacture such devices in China) , but more 'Made in China' for an unknown brand or unbranded item
That's actually the old and chunky Wago design, the new ones are smaller, easier to use and transparent (since you seem to appreciate transparency ;) ).
Notice that trip coil still gets AC voltage when thyristor fires up, so there is much more inductive resistance which determines the current through it, not 66 Ohm active one. So even if mechanism gets stuck somehow, it shouldn't set up fire, not immediately at least...
Anybody else notice that the Line and Neutral were wound around the ferrite in opposite directions? That's how the current is cancelled out, the magnetic field induced by one wire is cancelling the magnetic field of the other. When something grounds out one of the wires, it makes the other wires magnetic field strong enough to activate the GFCI.
I see them wound around the same direction. (Look at 13:50. I believe the two terminal at the bottom are going to the load. Both wires go though the center of the core in the same way.) The current though the wires travel in opposite directions, so the magnetic field is canceled out.
Much simpler than our gfci receptacles. As of this year or last, they're required to trip off if any component fails so there must be a slew of monitoring circuitry to make that happen and some brands run quite warm as well with no load plugged in.
I was going to say that they could have deleted the bridge rectifier if they used a triac instead of a thyristor, however triacs have diffo trigger currents for the 4 ac quadrants so that would give diffo trip currents for pos and neg phases. The burden resistor is higher in value than I expected. Still cleverly simple though.
Amazingly I too had a shock at the age of 11 or 12 I think it was when I was fixing an old TV using a mains plug, cable and crocodile clips. i forgot that the TV was still powered on and grabbed the crocodile clips to stop them shorting out. I got the full force through me at 240 volts 50 cycles as it was then and I can confirm that time slowed down very much. I too have the scars on my fingers to prove it. Also everything went black and stars passed before my eyes. I did manage to use my feet to push the cables away. Although I was screaming out the washing machine engineer in the next room thought it was a baby crying and ignored me.
It gives me a really reassuring feeling that most of the stuff you take apart is not powered by some black-box magic. If it contains everything that it needs, cheap doesn't have to mean shit, just means that the sourcing of the components has been optimized efficiently.
yadabub, hehe, would Clive be so cruel? I expect I'd just end up with lots of random LEDs turning up :-D Zastavan, I own a mobile phone as well, and a laptop computer. They can listen to me as easily as the Echo.
7:23 I picked up a couple of those Wago snap terminals (5-position) from Adafruit before. They are a tad bulky, but after tearing my scalp off trying to keep screw terminals from losing my wires or just getting stripped, I decided that the Wago blocks are just better for quick prototyping/testing, so I got a big box from Amazon. I think we can also get some from Arrow, including the wire-to-board terminals, which are mostly nice, but the bigger ones' pins don't fit protoboards...
The 12K resistor is a 'burden resistor', the transformer's output is a current, the burden resistor converts this into a voltage, which is needed to trip with.
You missed an opportunity, the finally should have been you sitting In a bubble bath dropping toasters to test the triggers. On the transparent discussions below, I like the idea of it being transparent so I can spot faults inside after use easier.
I see you wrote 300 milliseconds as "300 mS". What's up with that? I've seen it occasionally. But the symbol for second is the lowercase "s", and in electrical contexts the uppercase "S" means Siemens, so the potential for confusion is great. Is there some actual reasoning I've missed?
One advantage of the clear casing I can see immediately, back-lighting them with flickering candle LEDs, not for use on an actual distribution board, but something like a garage consumer for a bit of fun (for those of us who are odd like that!)... :D It is pretty interesting to see all the stuff on show, but, it's probably about as reliable as a politician, so, best not used for anything more than a lightbulb... :P
I was expecting a chip, but I guess the core windings provide all the amplification that's needed. One day I might break into my old Powerdown PC power saver - supposed to turn off peripherals when the PC is off, but my newer system is too thrifty to keep it reliably on. I guess it uses a single current sensing winding
Ah, I couldn't figure out how the test button+resistor could simulate a current imbalance without leaking to earth, which is not connected to the RCD. Your drawing gave me the answer.
I would worry more about the mechanical parts in it over electronics (okay, that too). If the trip signal is all good but the latch thing fails by play or something, you have still a problem.. Nice videos you make by the way, very educative/informative!
Since it only triggers on one phase, that explains the approx 20ms (or 1s/50hz) difference between the phases. I'd expect that u might get minor variation due to temperature coefficient of resistance as well.
Odd thing about pot noodles is that the two best flavours ( chicken & mushroom / beef & tomato ) were the ones they launched the product with in the 70s iirc... all the new & improved flavours since have been sadly inferior
Oh and the other odd thing is that it was initially a 'Golden Wonder' product... who then sold the pot noodle brand off and launched a competitor product... Marketing makes no sense to me, one of these days I expect to find that coke is being made by pepsi.
That small MOV is going to give you trouble eventually. They have a wear-out mechanism where every surge damages them slightly, and eventually they will fail from high leakage current and overheating. If there is no thermal protection a fire is likely. Common flame retarding agents in plastic don't do well with prolonged gradual heating, and even rated plastics can catch fire in those circumstances once the chemicals are baked out. It is not known how many house fires are caused by surge protected power strips and the like, but some fire investigators are very concerned about them.
And being in the panel, the current limiting due to wiring resistance is minimal. Hopefully, everything holds together long enough for the breaker to trip from over-current.
Yes, bad situation overall. Can't really put a small input fuse there either - if it blows the RCD would not trip any more. One solution is to filter out surge spikes with inductors instead, but more costly and larger. This seems a bad idea overall. I don't recall what "real" electronic RCDs do with the power supply, but I tend to avoid electronic types anyway. The classic construction with the current transformer directly driving the trip coil works fine for 30mA trip currents. Anyway, I don't think a small varistor has any business inside a breaker panel. There is a reason overvoltage supressors meant for installation in a breaker panel are as large as that whole RCD and come with thermal protection devices.
such a simple design, but it seems like it can only sense current in one direction, what happen if the fault is going through a diode? so the polarity of the spike is just being shunted by the reverse polarity diode, will it still trip?
Oh, good question! That might happen if you accidentally touch a old "hot chassis" electronic device, or if you touch a switching power supply somewhere between the rectifier and the transformer.
The trip times of an RCD and its relationship to electrocution are a red herring - RCD's are mandated with the intent to remove the power supply in a fault situation very soon after it has occurred, usually before anyone has been unfortunate enough to have received a shock. I have seen literature to support the claim that 10mA across the heart is sufficient to cause death in some people, circumstances may occur in which that may occur, without an RCD tripping.
How did the tests not trip your house RCD I wonder? Another very important and simple test is whether you can hold the RCD switch on against the fault condition. And I think ALL of these things should be made with clear plastic, assuming it can be fire retardant.
Looking forward to the day that you get your hands on a Type B RCD to reverse engineer although there not cheap. Hopefully one turns up that has been taken out of service.
There seemed to be something strange when you zoomed in the circuit schematic where the left side of the vid is out of focus but the rest is fine? Maybe some grease on the lens or something like that? It's quite peculiar
Just thinking about the time to trip the GFI... At 50 Hz (I assume the frequency you're using), one cycle takes 20 ms. It will trigger when the current leakage surpasses a threshold, but when zero-crossing, there is no current flow. When the leakage current is close to the trip threshold when the voltage is near peak, it can take nearly a half cycle before it would even know to trip (10 ms). So strictly speaking, the time it takes to trip could vary by up to 10 ms even with everything else being equal, just depending on where it was in the cycle when the test button was pressed. Unless the tester you're using knows this and intentionally compensates somehow.
we remove all of those breakers from equipment that comes in from europe .We convieniently name them EuroTrash .First thing that happens is we pull them out and throw them in the trash and swap out with Mersen ucc fuse holders .We have only had some equipment come in with those style RCDs and we get them passed ast part of factory equipment . They are rated for the current and guaranteed to blow on short or overload !We get so much equipment full of those little breakers mounted on din rails .They are only approved for communications equipment not motors,drives and plcs on equipment !Thats for the CSA or UL/ULC standard .Not to many recycling facilities for those breakers .Loads of copper silver and paladium in some of the contacts
I have such a leakage detector. I got one as a present a few years ago, when I was just 15 years old. I did not know what it was and opened it up. I saw the two big wires and the thin wire looping through the ring and even back then, just by common sense, I thought: The big wires cancel each other out, if current leaks, it shuts off. I have that thing laying around, I would send it to you to see how (old) german ones are made.
Can you do a Demonstration of OHMZ law? and explain what,why,how and anything else you might think of? I would love to hear your way of explaining it! Thanks!!!
I like the zoom on this camera, and would have no issue with you using zoom if it was always like this. I don't really have a *big* problem with zoom anyway, but on some of the other cameras, the quality of the image seems to drop, as if it's more of a post-production zoom, which I could do with pinch and push, or by using Windows and "+" to engage the "Accessibility" feature display zoom if I needed it. This actually seems to be zooming at the camera, not the software behind it. Either that, or it's capturing at much higher than 1080p, and so software "zoom" (crop and rescale) isn't noticeable in the finished footage.
IF the relay didn't open, I wonder what would fail first: the coil, the thyristor, or one of the diodes? My guess would be a diode. Most semiconductors graciously sacrifice themselves (in other circuits) to spare the precious fuses from damage. 😀
Chaplain Dave Sparks I hope it will keep trying untitled it eventually cuts the power by exploding itself. Because a small explosion in the breaker panel is still better than a dead person elsewhere in the house.
Dear Clive (also known in my circles as Mr Delicious Beard, not a joke me and my friend call this terrific chap Mister Delicious Beard 😊😋👌🤣) I have a question: the circuit breaker had a couple screws that would've opened it up in a jiffy. Could you open it up and show us the quench plates? I am super curious what those red blocks would've looked like on the inside 😀 Thank you very much for reading Clive! (or Mr. Delicious Beard 😋😄) a reply would be greatly and oh so very much appreciated! 😊 Thank you for the entertaining and informative content 👍
I vaguely recall that they need to trip in a fraction of a heart beat, not particularly in a segment of a waveform. edit: " Safety switches monitor the leakage of electrical current to earth through faulty appliances or incorrect wiring and disconnect the power quickly. A safety switch can cut off power in 30 milliseconds - a 30th of a heart beat. " www.dnrm.qld.gov.au/mining/safety-and-health/alerts-bulletins-search1/alerts-bulletins/mines-safety/residual-current-devices-earth-leakage-circuit-breakers?SQ_DESIGN_NAME=print-fact-sheet
Wouldn't the second half of the phase be delayed by 8ms, even if it had a 0ms response time? Seems to me that if the second phase trips within 10ms of the first phase, it is behaving as expected?
Question: How can I wired a RCD if when our power source is Line to Line(110VAC each) only and no Nuetral wire or Earth wire provided, The cooperative here in our place they only run 2 wire(line to line) only to their consumers and nothing else, Can I still use a RCD if not, any suggestion or remedy? Thanks
Is this marked as being a Type AC? I think that circuit would not trip on a pulsating fault (Type A), and so it would not be suitable for supplying phase-cut dimmers or other 'complex' loads.
bigclivedotcom Clive, what are the UK requirements for arc fault interrupters, and have you had much experience with them? That might be a good teardown. In the US, all new builds, and proper repairs require combo GFI/AFCI receptacles, where used. The combos are about $30 (which is why I haven't gutted one yet), but I expect that price to drop as production increases. As another commenter wrote, It's quite a feat to jam all the works into our much smaller electrical devices.
RCBO's have an earth connection. Clive says that this is to detect neutral/earth faults. Does that mean the earth connection is there as a 'reference'?
Wow that's a very ingenious circuit and avoids using an op-amp which is what other RCDs use, well the ones I've seen anyway. One question though, the 3.3K ohm test resistor will pass a current of 73mA which is too high for a safe test. My plug-in RCD which is similar to your black one uses a higher value, from memory I think it's 15K ohms which gives 16mA test current. It would be interesting to see a teardown video of your plug-in RCD for comparison, hint hint!
+bigclivedotcom @bigclivedotcom 30ma RCD Max Trip times are as follows: 1/2X tested for 2S = No Trip 1X = 300ms for BS EN 61008 or 200ms for BS4293 5X = 40ms Also, why did you not do a ramp test to see at what current the RCD tripped at? Oh, and some electronic RCBO's have a functional earth to ensure they continue working in the event of a lost neutral.
long time ago video Clive but still very informative. Question, you test it with Britisch plugs. which un ables switching polarity. But lots of EU countries use Schuko plugs.Which enables polarity switching. Also even CEE connectors are wired wrong. Would this GFI with these electronics work with a switched polarity? thus trip? or damage the thyristor? I ask because i see GFI's used and advised for in-cable solutions on generators and powerstation solutions with a Schuko outlet to campers/boats and outlets etc.
In their intended place in the circuit they would be breaking the live connection. If used in an appliance where that could be swapped then you would need a double pole version.
"The people who write the specs are just office workers..." That reminds me of what passed as discussions when the wiring colours were changed around 10-15 years ago. There were so many comments amongst the Chartered Engineers (I am one of them) about how stupidly dangerous it would be to swap the meaning of blue & black for example - I mean, it's not like it's important to know whether you are looking at a neutral or 415V phase is it...? They just told us that the changes couldn't be stopped so to just find a way to implement it.
Also, unless you're using an isolated mains generator / UPS, your test equipment seems to be proving that in Britain we never actually changed from 240V to 230V a few years ago ;-)
+gx8fif The colour change was apalling. From a distinctive phase colouring that was spaced across the spectrum to three dull colours. I think the primary motivation was cash. It certainly paid off for the management of the NICEIC who now refer to themselves as a safety charity, presumably to evade tax on the Part P racketeering.
It would be interesting to see the difference between Wylex and Volex RCDs as they are made by the same company and look the same but the Volex is the cheaper product. I always thought it was a branding and not a quality thing.
You could talk about the simple but critical loop back of stranded wire for termination. You'd be surprised what happens when a house electrician tries to wire a motor control center. Groan.
+bigclivedotcom -- hey, I noticed your comment in the video details where you mentioned that you'll be going back to the Moto G4 and that it's "a shame as the audio was louder and clearer." I know it'd be a little extra work, but why don't you film these videos using both the Moto G4 (for the higher video quality) _and_ the other camera (for the higher audio quality) _at the same time_ , and then rip the audio from the camera with the better audio quality and just drop it into the Vegas (or Final Cut, or whatever editing program you use) project, overwriting the Moto G4's audio track with that audio track. Then just sync them up. Shouldn't be too difficult, as you will have been recording into both cameras at the same time, technically. Just an idea! Thank you so much for the awesome videos, as usual =)
(5:10) - Clive,. I am an old electrician and when I say old, we are of the same era. Now, with these clamp-up terminals. When you've put the wire in and the clamp "ups itself" you can feel it through the screwdriver. If there is nothing there, it's only an incompetent electrician who might claim "I thought it was in there" BOLLOCKS! Any spark worth his salt would feel the tightening of the crimp. Thouugh your comment does have merit, for we have to protect all of ourselves from the fools out there. And fools who call themselves "electricians" are far and plenty. And, by the way... (10:50) - Your camera is very good. Most happy. Oh, and before I retire for the night, break out that "Stop & Grow" You'll do yoursel' an injury there fellah (Oh, I do love you.) And if you call me "Gay!", I'll bite your nuts off. See how you like that.
The 3k3 resistor's value seems a little low, 230V / 3k3 Ohms = 67mA. I would have expected the test button to test with the nominal fault current of 30mA, that is a resistor value of about 7k5.
+Ralf Baechle I think they're just doing a decisive test to make sure it trips to avoid resistor damage. Most other similar devices also do a generous test.
RCD = Royal Current Detector. No currents shall pass without the Crown's approval.
Now we need one for the AFCI's
Hahaha, good one!
In the US, GFI's are only required on appliances which require them for safety, and as such, those appliances must be sold with a GFI built in. I am not sure the exact definition of things which require them, but I do know they are required on things that function in or near water above a very low amperage.
The US and UK actually have very similar regulations, however, the point of failure are vastly different. The US regulates the appliances while the UK regulates the homes.
Richard Smith in the US GFCI's are required in wet locations, outside, bathroom, kitchen sink area, mud room, utility room, unfinished basement, pools. they are also required by OSHA on all job sites so there are a lot of extension cord type adapters for that purpose. we do have the option of going with a breaker or socket in applications. typical example would be a bathroom would have GFCI outlet, outdoor outlets would be strung to either a master GFCI breaker or a master homerun GFCI outlet. pool equipment would probably be on a GFCI breaker. temporary power drops are also required to have GFCI outlets because they're typically used for construction... OSHA requirement written into NEC. I have also started to see 240v equipment in fast food restaurants being put onto GFCI's.
oh and then any equipment that would be used in a bathroom like hairdryers and curling irons ( I'm surprised we don't have them on toasters yet because that is an essential bathroom appliance LOL ).
in some ways I like the idea in the UK that they have whole home protection, with the usual side effect of knocking out all the lights in the house.
AFCI, arc fault circuit interrupters are being required almost everywhere now (US). they originally started popping up about 3 years ago and were only required in bedrooms to prevent arcing when plugs were not plugged in all the way?, cords under carpets?, plugs jammed in wall behind bookcases?, Chinese "pink" electric blankets!. now they're being promoted as a way to prevent installation faults and the occasional siding nail through installed wire. however it was more of a "me company have patent, how do I get requirement in NEC!, and Get MO Money" and it has a mess of requirements on shared neutrals in 3-way (2-way? in the UK) switch boxes which can guarantee a house being retrofitted will guarantee a trip(s) and a subsequent lighting circuit(s) rewire.
I really like the transparent design of these safety devices. It enables you to directly see what the build quality is like. But I think a downside is the fact that it's pretty damn hard to read the ratings on the front.
you could also easily spot a fault (either manufacturing fault or fault after some time in operation). I think it's just for show / educational purposes and not actually installation. The transparent circuit breaker we had in our company had a lable on it: only for educational use. Maybe because the plastic wasn't up to swiss /european standards (i guess they should be fire resistant)
Downside is this kind of plastic is usually brittle.
The ratings could be printed on an area with nothing to see, with a non transparent background.
I like the idea of being able to see any internal skid marks or other damage. If they can make these in a way they won't become brittle and dangerous, they should make it part of the standards to require them... Old time fuse wire holders (at least in Australia) were easy to check for damage. Modern stuff is a pain and requires an electrician, which is expensive.
Yes, the usual unknowns, as with all Chinese 'safety' related devices from ebay are the longevity of the plastics used. Will they discolour? (Not so bad) Will they go brittle? (Could be bad). Are they flammable? (Could be very bad). That is one reason we have decent regulations in many countries. I am not saying this product is bad; it's just that we don't know. It's the stuff you can't see or isn't immediately apparent. The subtleties of these RCBOs is fantastic - do have a look at mikeselectricstuff if interested.
US suppliers _do_ make clear breakers, but usually they are strictly for R&D or education. Buddy at work had a few from Westinghouse. Very interesting, but those actually were code compliant and were flame retardant. The plastic was not a clear polystyrene or something like that one, but more of an off-color mostly translucent plastic. Still could see the guts working, tho.
Back in '64 I was "electrocuted" when a double adapter in my left hand broke apart. I was thrown back and my left hand gripped the exposed terminals tightly. My good friend had the sense to grab the cable and rip it from my hand and so saved my life. In a reenactment we figured it was about 10 to 15 seconds before I was "released" from the life sucking force. To me, it seemed like an eternity. I could hear and feel and see the individual cycles, which seemed to me to be at about 8hz to 10hz rather than 50hz. We were outdoors, on the back of a tip truck being setup as a makeshift stage for a concert. As I rocked back and forth on my back the trees above me shimmered in sync with the A/C and I felt like I was in an enormous centrifuge or washing machine. Still have a barely perceptible scar on my thumb from the burn. As you say, even 300mS would seem like a very long time because in a life threatening situation like this time really does slow down. After that, I purchased a portable ELCB and have always insisted that all band equipment pass through it.
iconoclad, It is great, you lived to tell us and all. I was 'cuted too a few times, but not as dramatic.
stories like that are about dc lol ... ac rarely makes your muscles stiff like that for such a long period of time ?! Well at least thats what i learned as a paramedic 20 years ago...
I helped somebody (for free) that I normally did sound for ( and used to get paid for ) with an outdoor event that called for rain. thankfully there was no incident. however I was prepared ( a trait that I had before Boy Scouts ) and had everything on stage ran into the trailer (were all the wedge/mains amps and wifi mixer were set up) to the least populated closest to the door PDU so if disaster struck I was one switch away from killing all AC onstage about 10 feet away. later I remembered that I had put together a GFCI box that I wish I pulled out. unfortunately 3 bands in the owner of the equipment who really didn't want to be there called it and we started packing up. 10 min. after the trailer was packed the rain stopped. and I still had to drive an hour home soaking wet from helping with tents, tarps, setup and mixing.
Having been at a church that did an outdoor picnic and always would have the worst weather for the entire year, I came fully prepared for this event and got no respect for my skill(s).
having both sampled of 120V US 60 Hz and 240V 60 Hz Filipino I feel your pain. and no I will never forget my experience either, even if I was just unplugging a fan from an extension cord. ( I did not bring enough electrical tape with me! ).
@The1Rausch Perhaps you should return to paramedic school for a revision, your recall is opposite to the facts. AC causes tetanic contraction, DC does not.
Reminds me of the time I was far too casual and stupid, and got a hand-to-hand 240V shock to remind me to be more sensible in the future.
Like you, I felt every pulse and they seemed to be around 5 Hz. Time obviously slowed down.
Fortunately the shock was applied to the fingertip of one hand otherwise my fingers would probably have locked onto the conductor (AC tends to do that) and it was such that I could jerk away from it without help (which was very fortunate because I was on my own).
Didn't last long. Maybe 10 pulses in all. No visual effects. Other than my underwear turning brown.
If standards people had half a clue they'd spec stuff like this to have transparent cases to make it easier to spot fakes. (Though I do wonder if it has the same fire rating).
Maybe a flame test to see if that clear plastic self extinguishes would do some good if it's tough enough plastic. Fakes are sociopathic if not just completely stupid so that easily overwhelms the notion that it might look like a toy to some... I almost want one of these for fun.
The flame retardancy did go through my mind. I'm not sure how easy it is to make clear plastics flame retardant.
if it's made from polyethylene, it does not come in clear. but there are some ECTFE based transparent fire safe plastics.
I'm not sure how you're defining "fakes." If it qualifies to the standards, how is it fake?
If it's just a lower cost alternative to an expensive brand, it's not really best described as "counterfeit" or "fake."
Landrew0, if the relevant standard required that such devices have a transparent housing it would be more difficult for unscrupulous manufacturers to pass off under-spec or non-compliant devices as genuine, since a simple visual inspection would immediately reveal that the internal components are not up to scratch.
So, another instance of Chinese crap being not crappy. This was a very enlightening video, Clive. All of yours seem to be, but sometimes the subject item carries more impact for me. Thanks once again.
I'm not so sure. I'm not keen on the lack of thermal runaway protection on the MOV. Others are questioning of the clear plastic is sufficiently flame retardant.
Perhaps Clive will chime in to share if there is the recycling symbol for which clear material is being used for the body? Other than not having the Stamp of Approval, he seemed pleased/satisfied with the device.
Might not be necessary (depending on the thermal/magnetic breaker rating). If the MOV fails low-resistance, the current draw will trip the overcurrent breaker (which will provide the necessary safety factor). The fact that the breaker would then NOT reclose (fault not cleared) would indicate to the user that there's a persistent fault.
Two questions: Can circuit to the MOV will support the trip current without burning up? Those look like some small wires. Second: I was under the impression that failed MOV got hot. Very hot. That's what caused some power strips to catch fire.
At
Well worth buying just to play around with. As to the problem with rising saddle clamps - a pretty common installation fault here, and one that I've had to rectify may times. Best to give the conductors a tug just to make sure.
I love design like this, real KISS! Its what I call "elegant", it uses the minimum circuit to do the job properly, no bells and whistles.
You weren't kidding when "it explodered". It really went bang in the video mentioned.
Combination MCB/RCD units are quite common in Australia. The double with ones are nice with their flags, but even the good brands leave out the flags in the smaller ones, making it hard to work out what tripped them.
Apart from that, they are brilliant, isolating a fault to one segment of the house so other power circuits and lighting are unaffected.
Great post thanks! Very informative.
LOL at your PDRC380 which my colleague designed. It's OK. We've had a few hanging round the office and the batteries have leaked which in my experience is due to small (but not zero) current drain. Maybe check yours from time to time.
You're right the LCD is difficult to read. That's as much due to refraction in the plastic window as poor design - which was non-existent on this range. For its successor I suggested the product designer responsible for the enclosure also designed the LCD, and that worked well.
There's no real difference in phase at x0.5; the AC test current is long enough for plenty of both polarity edges. For comparison, ramp tests use a dwell time of 300ms at each step.
Type AC x1 limit is 300ms, x5 is 40ms (this corresponds to full mains voltage on the EN61010-1 accessible voltage graph). These days I would think a tightening of the x1 response is appropriate and that's what you see when testing. Only selective breakers go over 100ms. RCDs really are a godsend.
I'm a bit doubtful about that MOV. I can see why they've got it - to prevent dV/dt SCR firing. But shouldn't it be downstream of the trip coil? Something so close to the supply will experience the worst of it and it's only a 10mm part.
The 3K3 test resistor is too low for 230V operation IMHO.
If you're interested in RCDs, have a look at Type A (pulsating DC ie half wave rectified) and then Type B (smooth DC ie electric car charging stations: yes we are going back to DC!)
+Mike Page I always remove the batteries from these units when not in use to protect against expensive leakage. I intend to test ordinary RCDs with various DC biased faults to see what type of circuitry defeats the protection. I'm guessing the proper pulses and DC fault versions are going to be quite complicated inside.
If you manage to saturate the CT without tripping you will indeed defeat the protection. That's how Robin Dlok worked. It was about 0.5A DC from memory, fairly quick ramp about 1-2s.
16:30 The resistor is likely calibration, yes. The diode is likely there to prevent "wrong direction" pulses doing bad to the SCR, probably unlatching it once triggered or such. The Capacitor will be parallel with the inductance of the core, likely to prevent any RFI getting at the SCR and randomly triggering it.
Well that circuit explains why one half wave takes longer.... It waits for the other half of the wave to trigger as it can only trigger in one direction. I guess most RCD's with a short half wave and a much longer half wave might use a similar concept.
OH i think you have answered my question i posted just now, it the "fault" were passing through a diode the feedback from the coil would always be out of phase getting clamped by the diode but it just "rings" inside the coil producing a smaller but still enough potential to trip it after a small delay. am i right?
If you look at the circuit, the diode on the gate of the SCR will short out (you will of course get the 0.6V Vf drop across the diode) any voltage that is positive on the Anode to the Cathode. The 0.6V VF is probably not going to trigger the SCR in this manner. On the NEXT half cycle The voltage across the diode will be Positive on the Cathode with respect to the Anode and this voltage will then trigger the SCR, tripping the RCD.
when you zoomed in on pad left hand side was slightly blurred, right side was fine.
Wonder if it was designed as a teaching tool device. Could show students/apprentices exactly what happens on a short.
Agree with Clive that the larger physical size of the 2-part module may be less likely to allow an internal phase/neutral short compared with the narrow-bodied enclosure type. The case of the grey module is marked 4kA fault rated whereas the higher 6kA seems to be common in the uk.
You really have me thinking. Please do a video on why 3P circuits with distorted loads (harmonics) trip GFCIs. It would be great.
One of the biggest problems with such loads is high leakage via ground referenced suppression capacitors.
The mike`s electric stuff video that you refer to is a particularly good one. "I think this is, possibly, slightly in excess of its rating" :-)
In Canada a lot of the new breakers being installed are combination breakers, GFI/GFCI/RCD, and arc-fault detectors.
We've not got the arc fault detectors here yet. Generally on 240V we tend to have louder and more decisive faults.
240v tends to go with bang
or in my case a pop when a mouse decided to chew through a positive and earth ring main cable it confused me at the start because we thought it was the fridge of the freezer that was tripping out as it was being very intermittent, eventually I was on the floor for over 15 minutes waiting for the damn thing to go pop and then I saw where the flash came from where the mouse had chewed it
they are on the way Clive , mentioned in the 18th edition draft document that's available for public comment now. Great video by the way.
I'm not a big fan of these combination breakers + RCD, as RCDs tend to fail much more often than breakers and I'd rather replace one device than two. And it's easier to bypass the RCD and still have overcurrent protection before I go and buy a replacement RCD (of course I mean at my own house). And for work I can just have 2 or three standard RCD values in the car and swap it on the go.
Lee x, did you find the mouse, probably up to ten feet/ three metres away? That happened with a friend's guinea pig when it chewed through the TV mains cable. The first they knew about it was when the power went off and most of a quivering guinea pig, minus front teeth, landed on the settee at the other side of the room. It didn't have the chance to do it again.
Note that the thyristor will only latch on for a half cycle. It shuts off on zero crossing. The 12K resistor is probably for noise suppression - just enough of a load to know it's a real imbalance and not some stray noise getting coupled into the circuit. Likewise for the cap - take care of high frequency noise.
I believe the 40ms trip comes from one half cycle of a heart beat as current passing through the heart for longer can make the heart go into fibrillation.
It also works out to exactly two full cycles at 50 Hz.
I've got one and modified it to use the test function to shut off power to everything on my workbench when a separate (emergency/safety) switch is pressed. One could also add a liquid level relay switch module to trigger the test circuit to shut off power when a certain liquid level is reached.
I wouldn't expect it to be such good quality with something as niche as this. Seems to be perfectly adequate to pass nearly any regulation. Would make a great educational tool for high schools. I am not sure how many have basic electrics classes in high school, i know I did.
Is my understanding correct, that the plastic casing has to flame retardant to some extent ?
I don't think it's possible to make plastic transparent and flame retardant. The Chinese ones could be a fire risk if I'm correct.
Perhaps this video needs a part 2
By the look of the plastic and the sound when Clive dropped it on the bench, it's moulded from polystyrene which is definitely not flame resistant.
*Doesn't "Made in China" already translate to:*
"This is not to code."
"This will not suppress an internal fire."
"This will be a fire hazard."
"This will void your home insurance."
"Don't come a-knocking when this fails and burns your house down because we are a fly by night company and you won't get a cent from us."
not ''Made in China' per say(no doubt some reputable brands will manufacture such devices in China) , but more 'Made in China' for an unknown brand or unbranded item
ElmerFuddGun I don't think so. You get what you pay for.
That's actually the old and chunky Wago design, the new ones are smaller, easier to use and transparent (since you seem to appreciate transparency ;) ).
Notice that trip coil still gets AC voltage when thyristor fires up, so there is much more inductive resistance which determines the current through it, not 66 Ohm active one. So even if mechanism gets stuck somehow, it shouldn't set up fire, not immediately at least...
Anybody else notice that the Line and Neutral were wound around the ferrite in opposite directions? That's how the current is cancelled out, the magnetic field induced by one wire is cancelling the magnetic field of the other. When something grounds out one of the wires, it makes the other wires magnetic field strong enough to activate the GFCI.
I see them wound around the same direction. (Look at 13:50. I believe the two terminal at the bottom are going to the load. Both wires go though the center of the core in the same way.) The current though the wires travel in opposite directions, so the magnetic field is canceled out.
This is calling to put some LEDS inside.
oh don't start. Then they will add bluetooth so you can reset it without fumbling in the dark. #stopOverEngineering
Reckless Roges lol!
Reckless Roges They should put a cellular modem so you can reset it on the other side of the world! #stopUnderEngineering
Ahhh. I can do drive by power cuts..........
The UK did that with the power meters instead with one master password for everybody.... until MI.. something I got involved.
With everything being transparent it needs more internal glow! Get on it Clive!
Much simpler than our gfci receptacles. As of this year or last, they're required to trip off if any component fails so there must be a slew of monitoring circuitry to make that happen and some brands run quite warm as well with no load plugged in.
I was going to say that they could have deleted the bridge rectifier if they used a triac instead of a thyristor, however triacs have diffo trigger currents for the 4 ac quadrants so that would give diffo trip currents for pos and neg phases.
The burden resistor is higher in value than I expected.
Still cleverly simple though.
Amazingly I too had a shock at the age of 11 or 12 I think it was when I was fixing an old TV using a mains plug, cable and crocodile clips. i forgot that the TV was still powered on and grabbed the crocodile clips to stop them shorting out. I got the full force through me at 240 volts 50 cycles as it was then and I can confirm that time slowed down very much. I too have the scars on my fingers to prove it. Also everything went black and stars passed before my eyes.
I did manage to use my feet to push the cables away.
Although I was screaming out the washing machine engineer in the next room thought it was a baby crying and ignored me.
So...we hope you've had a nice trip! ;)
It gives me a really reassuring feeling that most of the stuff you take apart is not powered by some black-box magic. If it contains everything that it needs, cheap doesn't have to mean shit, just means that the sourcing of the components has been optimized efficiently.
Reminds me of the show and learn style kids toys :)
The new dangerous version now they're all grown up.
bigclivedotcom it comes with 220-240V for Europeans or 110-120V for those who speak customary...
Heh, when you said "so let's aaah" it triggered my Amazon echo. Apparently "let's aaah" sounds like "Alexa"
Oh my gosh, it happened at 4:00 and 4:55 :-o
Shannon Gerry Triggered! Lol!
So let's aaah buy one of everything.
yadabub, hehe, would Clive be so cruel?
I expect I'd just end up with lots of random LEDs turning up :-D
Zastavan, I own a mobile phone as well, and a laptop computer. They can listen to me as easily as the Echo.
pfifo fast Lmfao!
7:23 I picked up a couple of those Wago snap terminals (5-position) from Adafruit before. They are a tad bulky, but after tearing my scalp off trying to keep screw terminals from losing my wires or just getting stripped, I decided that the Wago blocks are just better for quick prototyping/testing, so I got a big box from Amazon.
I think we can also get some from Arrow, including the wire-to-board terminals, which are mostly nice, but the bigger ones' pins don't fit protoboards...
The 12K resistor is a 'burden resistor', the transformer's output is a current, the burden resistor converts this into a voltage, which is needed to trip with.
Seems very simple and quite predictable, I certainly like both the construction and circuit design.
Thanks for showing us what it is.
RCD to BS61008 trip times according to BS7671 are 1/2 in = no trip. 100% in = less then 300mS. 500% in= less than 40mS.
You missed an opportunity, the finally should have been you sitting In a bubble bath dropping toasters to test the triggers.
On the transparent discussions below, I like the idea of it being transparent so I can spot faults inside after use easier.
I see you wrote 300 milliseconds as "300 mS". What's up with that? I've seen it occasionally. But the symbol for second is the lowercase "s", and in electrical contexts the uppercase "S" means Siemens, so the potential for confusion is great. Is there some actual reasoning I've missed?
One advantage of the clear casing I can see immediately, back-lighting them with flickering candle LEDs, not for use on an actual distribution board, but something like a garage consumer for a bit of fun (for those of us who are odd like that!)... :D
It is pretty interesting to see all the stuff on show, but, it's probably about as reliable as a politician, so, best not used for anything more than a lightbulb... :P
Hey Clive, Thanks for sharing another great video with us!
I was expecting a chip, but I guess the core windings provide all the amplification that's needed.
One day I might break into my old Powerdown PC power saver - supposed to turn off peripherals when the PC is off, but my newer system is too thrifty to keep it reliably on.
I guess it uses a single current sensing winding
Do it and make a video. I've been wanting to know about these and am too stingy to buy one for myself.
One video I'd really like to see is how an RCD behaves on the output of a dimmer, and how production companies manage their power distribution.
Ah, I couldn't figure out how the test button+resistor could simulate a current imbalance without leaking to earth, which is not connected to the RCD. Your drawing gave me the answer.
I would worry more about the mechanical parts in it over electronics (okay, that too). If the trip signal is all good but the latch thing fails by play or something, you have still a problem..
Nice videos you make by the way, very educative/informative!
I wonder how flame retardant the clear plastic is? Will it self extinguish?
Since it only triggers on one phase, that explains the approx 20ms (or 1s/50hz) difference between the phases. I'd expect that u might get minor variation due to temperature coefficient of resistance as well.
The difference was approx. 10ms , but yes that's what you expect since it takes at most half a cycle for the "right" phase to come around.
On the Socket&See they added the orange bezel after the housing dimensions were matched to the "displayed size" of the read-out.
I'm happy with my life I'm eating a chicken and mushroom flavour pot noodle and having a ham sandwich and watching big Clive
Pot Noodle? There’s a world of Asian pot snacks waiting for you, my friend.
Good combo. Chicken and mushroom is my first choice of Pot Noodle.
Odd thing about pot noodles is that the two best flavours ( chicken & mushroom / beef & tomato ) were the ones they launched the product with in the 70s iirc... all the new & improved flavours since have been sadly inferior
Oh and the other odd thing is that it was initially a 'Golden Wonder' product... who then sold the pot noodle brand off and launched a competitor product...
Marketing makes no sense to me, one of these days I expect to find that coke is being made by pepsi.
joinedupjon i know its stupid isn't it thw golden wonder ones are crap
That small MOV is going to give you trouble eventually.
They have a wear-out mechanism where every surge damages them slightly, and eventually they will fail from high leakage current and overheating. If there is no thermal protection a fire is likely.
Common flame retarding agents in plastic don't do well with prolonged gradual heating, and even rated plastics can catch fire in those circumstances once the chemicals are baked out.
It is not known how many house fires are caused by surge protected power strips and the like, but some fire investigators are very concerned about them.
And being in the panel, the current limiting due to wiring resistance is minimal. Hopefully, everything holds together long enough for the breaker to trip from over-current.
Yes, bad situation overall. Can't really put a small input fuse there either - if it blows the RCD would not trip any more. One solution is to filter out surge spikes with inductors instead, but more costly and larger.
This seems a bad idea overall. I don't recall what "real" electronic RCDs do with the power supply, but I tend to avoid electronic types anyway. The classic construction with the current transformer directly driving the trip coil works fine for 30mA trip currents.
Anyway, I don't think a small varistor has any business inside a breaker panel. There is a reason overvoltage supressors meant for installation in a breaker panel are as large as that whole RCD and come with thermal protection devices.
Great video Clive, I find this stuff fascinating, sort of knew what they did but now I know how.
such a simple design, but it seems like it can only sense current in one direction, what happen if the fault is going through a diode? so the polarity of the spike is just being shunted by the reverse polarity diode, will it still trip?
Oh, good question! That might happen if you accidentally touch a old "hot chassis" electronic device, or if you touch a switching power supply somewhere between the rectifier and the transformer.
The trip times of an RCD and its relationship to electrocution are a red herring - RCD's are mandated with the intent to remove the power supply in a fault situation very soon after it has occurred, usually before anyone has been unfortunate enough to have received a shock. I have seen literature to support the claim that 10mA across the heart is sufficient to cause death in some people, circumstances may occur in which that may occur, without an RCD tripping.
How did the tests not trip your house RCD I wonder? Another very important and simple test is whether you can hold the RCD switch on against the fault condition. And I think ALL of these things should be made with clear plastic, assuming it can be fire retardant.
Looking forward to the day that you get your hands on a Type B RCD to reverse engineer although there not cheap. Hopefully one turns up that has been taken out of service.
There seemed to be something strange when you zoomed in the circuit schematic where the left side of the vid is out of focus but the rest is fine? Maybe some grease on the lens or something like that? It's quite peculiar
if they ever make another star trek movie how is not Clive the best Scotty ever.
Love the clear construction - do you remember those clear - packaged ICs that some manufacturers used to make?
Thanks, BC. I bought one of these a few weeks ago. Now I don't have to pull it apart 'cos you have.
Just thinking about the time to trip the GFI... At 50 Hz (I assume the frequency you're using), one cycle takes 20 ms. It will trigger when the current leakage surpasses a threshold, but when zero-crossing, there is no current flow. When the leakage current is close to the trip threshold when the voltage is near peak, it can take nearly a half cycle before it would even know to trip (10 ms). So strictly speaking, the time it takes to trip could vary by up to 10 ms even with everything else being equal, just depending on where it was in the cycle when the test button was pressed. Unless the tester you're using knows this and intentionally compensates somehow.
I remember watching that video of Mikes....
"oops!"
Yep; the 'oops!' was classic.
can you test the DC breaker i got one and want to use them for my DIY solar powerwall
we remove all of those breakers from equipment that comes in from europe .We convieniently name them EuroTrash .First thing that happens is we pull them out and throw them in the trash and swap out with Mersen ucc fuse holders .We have only had some equipment come in with those style RCDs and we get them passed ast part of factory equipment . They are rated for the current and guaranteed to blow on short or overload !We get so much equipment full of those little breakers mounted on din rails .They are only approved for communications equipment not motors,drives and plcs on equipment !Thats for the CSA or UL/ULC standard .Not to many recycling facilities for those breakers .Loads of copper silver and paladium in some of the contacts
This is really nice and we like it so let's tear it apart...
I've ordered a nitecore tube lamp on your recommendation, it had best be the bees big clive
I have such a leakage detector. I got one as a present a few years ago, when I was just 15 years old. I did not know what it was and opened it up. I saw the two big wires and the thin wire looping through the ring and even back then, just by common sense, I thought: The big wires cancel each other out, if current leaks, it shuts off.
I have that thing laying around, I would send it to you to see how (old) german ones are made.
Can you do a Demonstration of OHMZ law? and explain what,why,how and anything else you might think of? I would love to hear your way of explaining it! Thanks!!!
I like the zoom on this camera, and would have no issue with you using zoom if it was always like this.
I don't really have a *big* problem with zoom anyway, but on some of the other cameras, the quality of the image seems to drop, as if it's more of a post-production zoom, which I could do with pinch and push, or by using Windows and "+" to engage the "Accessibility" feature display zoom if I needed it. This actually seems to be zooming at the camera, not the software behind it. Either that, or it's capturing at much higher than 1080p, and so software "zoom" (crop and rescale) isn't noticeable in the finished footage.
can you show the arc dampening in running the rcb, when the load is being disconnected.
Video quality: Right side of the frame is super sharp, left side is slightly blurry (see the paper around 15:30). Bad camera? Smudge on the lens?
IF the relay didn't open, I wonder what would fail first: the coil, the thyristor, or one of the diodes? My guess would be a diode. Most semiconductors graciously sacrifice themselves (in other circuits) to spare the precious fuses from damage. 😀
Chaplain Dave Sparks I hope it will keep trying untitled it eventually cuts the power by exploding itself. Because a small explosion in the breaker panel is still better than a dead person elsewhere in the house.
Do a bit on submersible pumps used in those plastic "rock gardens".
Dear Clive (also known in my circles as Mr Delicious Beard, not a joke me and my friend call this terrific chap Mister Delicious Beard 😊😋👌🤣) I have a question: the circuit breaker had a couple screws that would've opened it up in a jiffy. Could you open it up and show us the quench plates? I am super curious what those red blocks would've looked like on the inside 😀 Thank you very much for reading Clive! (or Mr. Delicious Beard 😋😄) a reply would be greatly and oh so very much appreciated! 😊 Thank you for the entertaining and informative content 👍
It's a series of fins separated by the red insulated board.
I vaguely recall that they need to trip in a fraction of a heart beat, not particularly in a segment of a waveform.
edit:
"
Safety switches monitor the leakage of electrical current to earth through faulty appliances or incorrect wiring and disconnect the power quickly.
A safety switch can cut off power in 30 milliseconds - a 30th of a heart beat.
"
www.dnrm.qld.gov.au/mining/safety-and-health/alerts-bulletins-search1/alerts-bulletins/mines-safety/residual-current-devices-earth-leakage-circuit-breakers?SQ_DESIGN_NAME=print-fact-sheet
Wouldn't the second half of the phase be delayed by 8ms, even if it had a 0ms response time? Seems to me that if the second phase trips within 10ms of the first phase, it is behaving as expected?
Question: How can I wired a RCD if when our power source is Line to Line(110VAC each) only and no Nuetral wire or Earth wire provided, The cooperative here in our place they only run 2 wire(line to line) only to their consumers and nothing else, Can I still use a RCD if not, any suggestion or remedy? Thanks
If the RCD under test had failed to trip, would the RCD in your power grid trip instead? Could it simply trip before the tested one?
Is this marked as being a Type AC?
I think that circuit would not trip on a pulsating fault (Type A), and so it would not be suitable for supplying phase-cut dimmers or other 'complex' loads.
bigclivedotcom Clive, what are the UK requirements for arc fault interrupters, and have you had much experience with them? That might be a good teardown. In the US, all new builds, and proper repairs require combo GFI/AFCI receptacles, where used. The combos are about $30 (which is why I haven't gutted one yet), but I expect that price to drop as production increases. As another commenter wrote, It's quite a feat to jam all the works into our much smaller electrical devices.
RCBO's have an earth connection. Clive says that this is to detect neutral/earth faults. Does that mean the earth connection is there as a 'reference'?
Wow that's a very ingenious circuit and avoids using an op-amp which is what other RCDs use, well the ones I've seen anyway. One question though, the 3.3K ohm test resistor will pass a current of 73mA which is too high for a safe test. My plug-in RCD which is similar to your black one uses a higher value, from memory I think it's 15K ohms which gives 16mA test current. It would be interesting to see a teardown video of your plug-in RCD for comparison, hint hint!
+bigclivedotcom @bigclivedotcom 30ma RCD Max Trip times are as follows:
1/2X tested for 2S = No Trip
1X = 300ms for BS EN 61008 or 200ms for BS4293
5X = 40ms
Also, why did you not do a ramp test to see at what current the RCD tripped at?
Oh, and some electronic RCBO's have a functional earth to ensure they continue working in the event of a lost neutral.
You find the neatest things on eBay. I wish all of my electronics, breakers included, were transparent.
Is the plastic a different type because it's transparent? If that be the case, I wonder if it has different flame retardant properties?
long time ago video Clive but still very informative. Question, you test it with Britisch plugs. which un ables switching polarity. But lots of EU countries use Schuko plugs.Which enables polarity switching. Also even CEE connectors are wired wrong. Would this GFI with these electronics work with a switched polarity? thus trip? or damage the thyristor?
I ask because i see GFI's used and advised for in-cable solutions on generators and powerstation solutions with a Schuko outlet to campers/boats and outlets etc.
In their intended place in the circuit they would be breaking the live connection. If used in an appliance where that could be swapped then you would need a double pole version.
"The people who write the specs are just office workers..." That reminds me of what passed as discussions when the wiring colours were changed around 10-15 years ago. There were so many comments amongst the Chartered Engineers (I am one of them) about how stupidly dangerous it would be to swap the meaning of blue & black for example - I mean, it's not like it's important to know whether you are looking at a neutral or 415V phase is it...? They just told us that the changes couldn't be stopped so to just find a way to implement it.
Also, unless you're using an isolated mains generator / UPS, your test equipment seems to be proving that in Britain we never actually changed from 240V to 230V a few years ago ;-)
Just to add to the fun, in electronics, black is typically circuit ground/common. But in US building wiring, black is hot.
+gx8fif The colour change was apalling. From a distinctive phase colouring that was spaced across the spectrum to three dull colours. I think the primary motivation was cash. It certainly paid off for the management of the NICEIC who now refer to themselves as a safety charity, presumably to evade tax on the Part P racketeering.
Ooh. I liked that waygo terminal. Gonna order some of them for work ☺
There a video on my channel dedicated to them. Just search my videos for Wago.
What is the output voltage of the sense coil ?
You should get a Fluke 1662 or 1663 or 1664 Multifunktion installation tester.
It would be interesting to see the difference between Wylex and Volex RCDs as they are made by the same company and look the same but the Volex is the cheaper product. I always thought it was a branding and not a quality thing.
ya this why cheap stuff can be just amazing, thanks for the video clive
You could talk about the simple but critical loop back of stranded wire for termination. You'd be surprised what happens when a house electrician tries to wire a motor control center. Groan.
+bigclivedotcom -- hey, I noticed your comment in the video details where you mentioned that you'll be going back to the Moto G4 and that it's "a shame as the audio was louder and clearer."
I know it'd be a little extra work, but why don't you film these videos using both the Moto G4 (for the higher video quality) _and_ the other camera (for the higher audio quality) _at the same time_ , and then rip the audio from the camera with the better audio quality and just drop it into the Vegas (or Final Cut, or whatever editing program you use) project, overwriting the Moto G4's audio track with that audio track. Then just sync them up. Shouldn't be too difficult, as you will have been recording into both cameras at the same time, technically.
Just an idea! Thank you so much for the awesome videos, as usual =)
(5:10) - Clive,. I am an old electrician and when I say old, we are of the same era. Now, with these clamp-up terminals. When you've put the wire in and the clamp "ups itself" you can feel it through the screwdriver. If there is nothing there, it's only an incompetent electrician who might claim "I thought it was in there" BOLLOCKS! Any spark worth his salt would feel the tightening of the crimp.
Thouugh your comment does have merit, for we have to protect all of ourselves from the fools out there. And fools who call themselves "electricians" are far and plenty.
And, by the way...
(10:50) - Your camera is very good. Most happy.
Oh, and before I retire for the night, break out that "Stop & Grow"
You'll do yoursel' an injury there fellah
(Oh, I do love you.)
And if you call me "Gay!", I'll bite your nuts off.
See how you like that.
I love clean cased stuff I like seeing the circuit boards more stuff needs to have clear cases in my opinion. :)
The 3k3 resistor's value seems a little low, 230V / 3k3 Ohms = 67mA. I would have expected the test button to test with the nominal fault current of 30mA, that is a resistor value of about 7k5.
+Ralf Baechle I think they're just doing a decisive test to make sure it trips to avoid resistor damage. Most other similar devices also do a generous test.
Was only the left side of the video out of focus?
You may have had a stroke.
really weird isnt it? I noticed the same effect on the last video
Why don't you add a backlight? Is the clear plastic rated for heat too...