Just to note. The #14 NO is the NO held closed for the stop loop of a latching circuit for a 2-wire start/stop. The coil wire would be looped through that contact and a NC pushbutton which is the stop button.
Hi BC, the "shunts" you mention are called shading rings and they create a second magnetic pole that is out of phase with the main pole to hold the iron circuit closed as the control voltage passes thru the zero crossing. :)
I worked at an electrical supply house for some time while at school; there's some very cool capacitor switching accessories for all of the contactors used to deal with. Essentially, it would switch a smaller module that was in parallel with the contactor with a high value resistor in circuit a few milliseconds before switching the actual contactor, which would trickle some current into the capacitors; in turn helping with the inrush that you were discussing.
You know after watching you for a bit, I found my love back for electronics and making my own diy projects. Thank you. Right now I’m working on a digital/analog (red and blue leds).
Used to work on some Irish made ice builder systems that used Omega (or similar name) branded contactors, found to our cost they would randomly stick in, the ice builder used the same condensing units as a milk cooling tank which had priority for the units, someone had used a spare terminal on the contactor to join a couple of wires, one night while making ice the milk tank called for cooling, this contactor didn't drop out and the two cooling signals being on at once caused a latching effect which froze the milk and sheared the paddles off the stirring motors!
That looks to be a very good copy of an older Telemecanique contactor. I have put in many different contactors in my time. There are many different brands but they all look pretty much the same inside. Keep up the AWESOME work Clive.
When I worked for a major Australian power company, our industrial service techs were told by their leaders (young people, straight out of Uni, with no real world experience), that they wern't allowed to fault find control equipment with the panel live. These were industrial application gas burner controls, sometimes quite complex and the only way of fault finding, in most cases, you needed power on. We have RS Components here in Aust. and they are very good to deal with.
I love using relays. There's something rather satisfying about the click. Very useful too when you only want to use a small switching voltage to activate larger loads, you could easily make a Hive style Internet heating system for a fraction of the costs, in the £20-30 range instead of £200+
Do you know, Clive, I've been following your channel for over a year now. I went back over some older ones and was surprised how much I'd managed to soak in. So thanks for the education mate.
I've started finding the phrase "take it to bits" slipping into my everyday conversations inadvertently. Also been getting urges to just starting take random things apart just to see them.
For all you wondering (this is AFIR) 11 Common 12 Opener 13 Close Higher numbers refer to special funtions like timer based contacs A1/A2 is the coil Also... we call these "Schütz" in german... to distinct them from relays. They break befor make, thus they can be used to switch phase alignment for i.e. reversing sync. motors. There are a number of specialized relays of that kind. I.e. the aforementioned reversing of motors, or in conjunction with a thermal overcurrent sensor for breaking the supply to a stalling motor. Nowadays the majority of these are made to work with PLCs, in my country it is 24V dc And i want to make this one clear: As voilently as a keep my moneys together, i would never use a chinisium crap relay in something that is supposed to generate (abstraction layer to be inserted here) money. Siemens, Hager, ABB... that is the way to go. Not cheap but also not prone to fail in less than a decade.
It seems Clive is a never ending encyclopedia of awesome electronic goodness. You sir need the electrical industry's equivalent of a Emmy Award...or two.
Sometimes the quality control is lacking in the little things - like the springs. Springy metal doesn't "just happen" due to the shape. It takes good design and consistent production (heat treating) methods. Spring today... flimsy (or broken) piece of wire tomorrow.
Good video. I've had problems when pricing work. I said it would cost £3500, and this other company said they could do it for £2000. They were using all Chinese parts. Not saying that's wrong, just make life hard for the small firms that are trying to do the right thing.
Talking about a factory when the machinery stops, reminds me of a service call I did some years back. This company was into making "filtration" products, and the input to the machine in question was big rolls of paper, which the machine was supposed to punch large discs out of. The paper production was continuing, and they were running out of places to put it. The controlling hardware on the machine was two boards full of 4000-series CMOS parts, and apparently some power supply issue had taken out a number of chips. The "fixer" on site couldn't quite seem to get a handle on the situation. There was a spare set of boards but they were of a different revision and both needed to be swapped out at once or it wouldn't work. We didn't find that out until the folks showed up who made the machine. I found a bad sensor whose wire ran inside the same conduit as some 220V power, which was probably why it failed and on replacing it they insisted that it be done the same way that it was, so I'm thinking that it didn't last. Perhaps some transient suppression on that particular input would have helped? I remember the guy's jaw dropping when I sketched out a simple crowbar circuit that could be put between the power supply and the machine to protect the boards in the event of future power supply issues. Two of us outside guys plus the factory guy plus the reps from the machine maker and after a couple of days it still wasn't up and running, management was not thrilled...
With regards to selecting the right contactor for a type of load, figures are stated on them AC1 is it's purely resistive rating. AC2 is for wound rotor and secondary resistance motors. AC3 is for starting and running squirrel cage motors (normal duty). AC4 is for inching and or plugging squirrel cage motors (considered severe duty). AC-6a is for switching transformers and other low impedance high inrush loads. And our old friend AC-6b is the capacitive rating usually reserved for switching capacitor banks for power factor correction, and it generally involves early make late break parallel contacts and big wire wound resistors to extend the contact life. For things like car park lighting go with the AC4 rating. PS I use those contactors that you tore down today in older machinery all the time, never had a problem with them, the reason for using them is not the cost, it's because they are exact copies of the old Telemanique contactors that are no longer produced so they fit all the existing mechanical interlocks, and auxiliary contacts, and motor overloads, straight swap and all the electrical and mechanical safety interlocks are maintained, proper job. Cheers, Michael.
Looks just like a Chint contactor from China. I have used Chint and it's pretty decent gear. As for star delta there should always be a mechanical interlock between the contactors to prevent both being engaged at the same time. Some of the old systems didn't have that safety added
Also keep the contactor rating for inductive loads in mind. At a public transportation company we replaced contactors which were used to switch the sodium-vapor lamps at the tram stops. Turns out their combined ballast load was too much for continuous operation and the arcs jumping across the contacts had burned them away over time. There was nothing left of the contact plates.
As an Electrician who works with contactors like this (and even bigger ones) every day... I NEVER thought about the possibility to cause very nasty shorts when pushing them in with a screwdriver. Thanks for opening my eyes. I will make sure to use an isolated tool from now on.
Pyrrha Nikos when you have a contactor setup with forward/reverse wiring, both contactors better not be drawn down at the same time. Usually you have the coils wired through the NC aux contact so you have electronic interlock
Yeah, that's switching 101, really. No what I meant was (and not I'm not even sure if that's what he meant in the video) that it's in theory possible to bridge, say, contacts 11 and 13 when jamming a plain old metal screwdriver in there, assuming the contactor is old or broken or cheap or any combination thereof. And since 11 usually is on L1 and 13 is usually on L2... nasty things might happen.
Pyrrha Nikos that can't/shouldn't happen by design, the manufacturer has to get several type test certificates to sell his stuff and the possibility to touch live contacts won't help them get these 😉 what Clive meant was simply that you shouldn't press a contactor in by hand if you are not sure that there are others drawn down that could cause trouble by shorting something or mess up the routine of the plc or hardwired controls
That's not what he meant, if you look at a star/delta starter circuit the star point is shorted on the other side of the contactor, but if you bring the delta contactor in at the same time you short all 3 phases through the star point. Ryan also brings up a good point, in that case you'd short 2 phases instead of all 3. Plenty of BOOM though - I've seen the aftermath of an engineer thinking "Oh we don't need interlocking contacts she'll be right!"
Christopher Andrews Exactly what I said! There are many more typical circuits where pushing in a wrong contractor would lead to a fatal error. one example is star/delta of course. but there is also a serious chance of fucking up the control circuit if you push in random relais or contactors even if you don't blow everything up by shorting something. shoving a screwdriver up to the contact is unlikely if you don't use brute force to push it in
DIN = Deutsches Institut für Normung - German Institute for Standardization. Bonus Info bit: Many people think it stands for "Deutsche Industrienorm" (German Industry Standard), but that is just not right..
main difference between contactor =Schütz Relais i learned are: Double Contacts to better insure safe disconnection (not connection, safety first) 3 main power contacts 1-2 3-4 4-5 and some NO and NC auxiliary contacts for control and feedback "low power" cuircuits. And also: dont poke it with a stick unless you know 100% what youre doing, a short circuit at 600V and somehundred amps makes go-boom the whole panel. (edit: typo)
While reading through the log book of an elevator I found an entry that explained the splattered contactor on the table. It said. "Needs new contactor, old contactor refitted. I had a little incident."
Late comment, but FYI: DIN stands for Deutsches Institut für Normung (= German Institute for Standartisation), another common use is Deutsche Industrienorm (= German Industry Standard).
I've seen high pressure sodium floodlighting installations where the PFC capacitors in the fittings have gradually degraded over a couple decades to the point where the low PF has started causing the MCB to keep tripping!
Simple problem, Dremel hand tool variable speed control has become on or off at full speed. Assuming mechanical potentiometer switch...fixable by cleaning maybe or waste of time? Control is 2-10 it kicks in at full speed at 4.
Could also be the pot is just worn out. Had a similar problem on my old Ford Pinto's throttle position sensor. The engine idled ok, but died when you pressed the gas pedal. Replaced the "sensor" (pot) and the car ran perfectly again.
My first experience with industrial contactors was at my middle school. The school's baseball field had three light towers that each had about 18,000 watts' worth of lamps (18 lamps x 1,000 watts) totalling 54,000 watts. They were all controlled by just three standard 20-Amp key switches. One day my physics teacher showed our class the inside of the light control system (I think he was teaching us about Ohm's Law at the time, and was demonstrating methods of controlling large amounts of current with low-current devices). The three switches controlled about 20 or so industrial contactors, which in turn controlled the light towers. At the time I thought it was cool, but now I think that system might have been a bit over-engineered.
The shunt as you say is actually a shading coil. This gives the coil a magnetic bias so that i can pull in the metal core. If it didnt have shading coils it would not pull in the core.
In the power station we often worked on these live in control circuits during fault finding. We used 110v ac contactor coils and if they were faulty they certainly buzzed!
The inrush current is definitely an issue for driving SMPS loads. I had a PC with a 600W PSU connected to a digital lamp timer with a small relay timer inside and within about 20 cycles the relay failed in the closed (on) position. You could still hear the coil energize and de-energize when cycled, but the relay contacts just wouldn't separate.
You can get round that in some situations with a PTC Thermistor. However you have to know how to specify what type etc as too high a temp-co or resistance and your PSU can grey out or go bang etcetera and too low a power rating and the PTC will go pop. You "can" use a PTC all the way up to a 3KW load but personally I would say that's way out on the hairy side. One other option is an inductor. Again it's got to be specified properly as for mains work you really need something with insulation capable of at least 600V (due to back EMF and all sorts of nasties). On top of that you need a low DC resistance to avoid heating etc and the relevant category of insulation temperature (I can never remember which category is which temperature). Or alternatively the "bodge it and scarper" method I use at home is to use a relay capable of 10 or more times the load current. IE a 25A relay for a 600W load. There are mercury wetted contact type heavy duty relays you can get on some surplus sites which are useful for this but personally I'd not use them as I'm a bit paranoid about mercury.
My work uses absurdly huge lighting contactors for the outdoor halide lighting circuits. These things make the most satisfying KACHUNK when they pull in or drop out. -Edit: Found a Hopi on flash sale at AliExpress! It's on the way now.
Hi Clive, another reason why contractors are used is that the design of how they work clean the contacts as they energise and de-energise you don’t get that with relays
Hey clive, still awesome & informative videos. I've got one suggestion tho: when testing industrial components like switches and contactors, it would be really nice to have an industrial one for comparison. I know ot would be more expensive to buy but in this case i'd like to see into a Müller or Siemens or whatever industrial brand contactor. Maybe they are better built, maybe you can't spot a single difference. Let me know what you think!
All of the reasonable to good quality ones will look pretty much identical to this. It's the quality control that's important. I am much more comfortable installing the 110$ Schneider vs the 10$ ebay special.
Ave recently compared a name brand relay to a cheap chinese relay. There were quite some differences, most notably in the contacts which were build to last a lot longer. Plus, for the industrial reputable brand relay / contactor you'll get a guarantee of a certain number of cycles, so there is probably some testing going on the factory. Not only does this increase practical reliabilty, it's also probably something you can insure against. No way the insurance is going to pay out if you don't have the parts with the guaranteed number of cycles (or if they find out you went over the number of cycles, although I wouldn't know how they could).
yeah i know it looks pretty decent, would still be cool to be able to show the difference, not only with contactors. Clive should take some more expensive parts to bit :) and i agree that you can try those out if they are reliable but still, for a factory they cannot afford any downtime, so reputability of the used brands is critical. I'm not saying they are worse, but they could be.
Contactors in HVAC usually fail due to ants (insects) getting in between the contacts, the tell tell sign is a loud BUZZING coming from the contactor. In the south USA this and capacitors are the #1 failure modes of the outside condensing unit. Be aware of the repairman that says you need a new A/C unit. Always get multiple opinions and do your own research.
Yeah I live in Kansas a.c. went out I know enough to take a look and fall had just hit so cold st night but hot during the day, anyway air shut off so the ants had built there nest up there at night cuz it was warm.
Similar problem in Australia. Our A/C outdoor units get a 6-monthly spray of persistent insecticide to prevent this "problem" (failures arising from such "external sources" are NOT covered by equipment warranties!)
That's what happened to my AC unit! Made a forum post out there because I thought it was super uncommon, guess not: hvac-talk.com/vbb/showthread.php?2235721-Bug-in-contactor-caused-AC-compressor-buzz
I once repaired outdoor equipment and concluded that certain ants were attracted to various power rails. I think 48v DC was one of the popular flavours.
The last place I worked had a unit that used about two dozen VFD's and contactors (rated from 9-30 amps depending what was being driven) all labeled Allen Bradley. I was replacing one failed contactor and when I opened the A-B box, the wrapper and contactor inside were showing another brand, bit made in the came country as printed on the box. So it seems that a major brand name is not a guarantee that they actually made the component. And yeah, contacts welding closed on a conveyor belt motor causes anxiety in workers that expect the belt to stop when they pause it.
Excellent video...I have had some recent experience having to replace a similar sized contractor that had it coil vaporized after the status light spring contact shorted. Not a great light fuse considering it was for a heat circuit. Fortunately it was not too cold out. Very interesting stuff to “play with”.
You should do a ferrule and crimping vid. Outside Europe and a few bits of Asia they are not as common. I would have no trouble using these in the home. Just not in the industrial space.
A rack of these came in the power distribution panel of a machine made in China. One of them melted a terminal. Diagnosing the failure, looks to me like the contact buttons on that one strip were not firmly closing and that there was some arcing on that one leg. I was thinking of replacing the whole rack with domestic components ($$$$). Thankful to have found this video, confirming reasonably good component quality. So I’ll just get a replacement off of AZ for 12$ and carry-on. Thanks!
The contactor in older Mitsubishi electric r22 air conditioners have a sticker saying “don’t push this button” over the plunger. I always feel like pushing the contactor due to the reverse psychology effect
My first "regularly-paying job" post A-Levels was assembling larger versions of these at the Arrow-Hart Plant in Roborough, Plymouth (early 1970's). No "Batch Release" on those - the NCB expected (and got) individual test certificates on every one we assembled. That was the job of the "real" Engineers - us plebs were just the "Assembly Operators"!
In my opinion as an electrician if your going to fit one of these cheap devices I'd recommend installing an automatic fire extinguisher in the control panel! I've seen loads of these cheap contactors from China fail. Im in NZ and everything here has to be approved and certified before its imported. Im sure its the same in most parts of the developed world. I've seen these things on aliexpress for $10 or less with free shipping, but the real deal quality stuff from the local wholesaler will set you back probably $200 if its from Schneider or Allen Bradley etc. Thats because these companies have proper quality control processes and the products are tested and certified. No proper electrician would fit this rubbish and sleep at night.
Another tip for switching high loads is to use multiple contacts. Than you connect one side to pin 1 and bridge to pin 3 and pin 5 and on the other side you connect to pin 6 and bridge to pin 4 and pin 2. This way the resistance should be more equal over the contacts and hopefully prevent burning the contacts (its kind of a dirty trick in my opinion). I have taken many apart, sometimes when the contacts are in a not to bad state I clean them with a fibreglass-pen.
There is a list of utilization categories which divides contactors by their expected usage - a typical AC-7a contactor rated for eg. 40A might won't last long driving a motor rated for 25A, because of contacts burning out. Obviously, it will work at first, but will be prone to failing earlier. Proper category for electric motor might be AC-3 (which is shown on the video), but only on squirrel-cage motors. For mentioned MHL lightning best suited would be AC-5a contactor. Overrating contactors may be good when you need two or three of them, but in industrial use, when you have hundreds of them in one place, it might cost a lot more - not only higher rated contactors cost more, but they sometimes are bigger in size, which leads to bigger switchgear, consuming more place, and so on. More important is choosing proper contactor for expected usage. Bit more info: en.wikipedia.org/wiki/Utilization_categories
star-delta and fwd/rev should always be mechanically interlocked. Every time. Contactors can and do weld in. Interlock kits are so cheap. People who omit them are even cheaper.
I'm an automation technician in America for a warehouse that uses high speed sortation equipment from Dematic and we use similar contactors to this but they mostly use 120vac and most PLCs I deal with use 120vac for their inputs and outputs. Not too often do we use 24vdc PLC cards.We do have them in things like out automated HVAC system and our shrink wrap machines but otherwise it's mostly Modicon M340 controllers. I do wonder if those contactors at the place you described where they would trip up the PLC had Transient voltage suppressor resistors built into them? They suppress voltage spikes that can fry PLC inputs... kind of like a fly back diode does.
I really liked the mercury displacement contactors for HID lighting. They would last forever. And they need to, now that they are so hard to get anymore. :(
We use pretty similar contactors (but from Kloeckner Moeller) with the additional contacts on top at work in an old machine for heaters and motors. Yeah, have had stuck contacts, but usually the original ones work pretty okay :). Cool to know about these clones :) and how to take them apart, didn't know that you can :D. This chinese one does actually look quite good :).
Hi, Clive.. Yes the contactor looks pretty standard construction, all that i would need to check is the contact material. The spec sheet should state the material used.
A Friend of mine has an industrial oven for paint spraying, and it has two of these contactors in it, one of these and one of its bigger brothers. Both of them were a Pile of **** burning up quickly. I replaced with an RS Solid State Relay much better :) - Good Vid
I've rebuilt dozens of high quality Allen-Bradley's. It's a little sketchy, but what are you going to do when production stops, and the managers ... don't want to stock parts? Clipboards ... you gotta hate em.
It's already happened in my industry. The JIT (just in time) and KANBAN approach is only any good if the clipboard muppets know how to actually analyse the lead time data etc. Most of them have clip boards because 1 their memories don't work 2 to have data on so they can quote it to pretend to not be stupid and 3 to do crayon drawings.
I wonder how many cycles they are rated for? And more importantly how many cycles they will actually survive? Given the average Chinese manufacturer's rather generous assumptions! Regarding the HID story that is why contactors typically have multiple ratings. I often see 30A contacts rated 24A or less for HID loads.
There's a common cultural idea in China called "face" (as in "saving face") that basically completely justifies straight up lying about something rather than admitting weakness. In the case of so many of these 'straight from the factory' aliexpress and ebay products, this tends to manifest as manufacturers grossly exaggerating ratings of products, usually because they won't admit being weaker than a competing product. This can end up with things being rated an order of magnitude or more higher than actual facts indicate, due to co peting products repeatedly 'out-facing' each other. It's seen as an entirely normal thing in China, but tends to annoy anyone here when they buy a 50,000,000 mAh battery pack and are greatly disappointed. As a rule of thumb, you have to assume the ratings listed are exaggerated to some degree for any product not quality assurance tested directly and marketed by a western company (although it's been cropping up I've noticed even in recognized brands' products in recent years). I would generally trust industrial components though to a higher degree as the importance of efficiency of the production processes in China would lend itself to well designed factory gear. Then again, you also often end up with the 'reject bin' QA failed products when buying cheap off ebay or aliexpress. I guess buyer beware is the only real safe assumption, that and test the shit out of anything that has the capacity to blow up under normal operating conditions BEFORE using under said conditions.
These look like ripoffs of Telemecanique contactors. Those are much more expensive of course. The auxiliary contact is normally used for feedback to the PLC to let it know that the contactor is currently activated. I've worked with quite a few of those years back.
Good you mentioned incandescent and lighting inrush current. It is critical to design for it. Stage/theatrical lighting can run 10,000 amp inrush. Normal industrial switching and contacting won't handle that!
This reminded me of a house fire 100m further up the road. The parents woke up, the man told his wife to go outside while he got the children. But he and the children of 4 and 2.5 never came out again. You try to imagine the dread that mother must have faced but I'm sure it's nowhere near how much she actually felt. The fire was started by a spark from the fridge thermostat which ignited isolation material. It's a place you never look and it's an appliance you keep running 24/7 for decades. These people weren't marginals who bought some cheap brand or running a meth lab in their kitchen.
Interesting item Clive, at some point in the future maybe you,d discuss the difference between inductive, capacitive and DC loads and how to select the right contactor for the job can be very confusing with all the different manufacturing terminology's that you find in catalogues and the like cheers Clive Sean.
So would it be devices like these but for lights as mentioned that cause that [Thunk!] sound in movies and TV whenever they show big banks of lights turning on or off like in warehouses and parking garages?
Yes, generally they are bigger in size as they would switch a much higher current load. We use contactors to turn on whole lighting panels for retail stores
I would have said more of a *Tak!* (but hey, onomatopoeia is subjective). you can also run a line-delay between contactors and a single switch operates any number of arrays (of lights) in sequence. but you'll hear the *tak-tak-tak-tak-tak* like someone rhythmically switching the switches, when it's only actually the one switch, and while it looks cool, it's not just for effect.
About using cheapo components in industrial automation, only do it if you make significant amount of the same machine, if you build 1000 machines, then little savings per every bit and bob can really add up. If you have the time it might be even worth it to tear some sample components down and test it to failure. If you build one and only machine or in low quantity, take the good components, the little money saved is just not worth the headache.
With reference to the maintenance man at the RS trade counter, not accepting you're judgement on the contactor failure welding in on position. Most see the good advice as intimidating or insulting and it makes them look incompetent, so they normally behave in a dismissive way. Some will get agitated and argue with you, which make you feel bad for interfering with their business. So for this reason its best practice to not give unsolicited advice even if you know they are completely wrong. Speaking from bitter experience...its different if they ask for help, but this never really happens. Most would rather fail and make mistakes and cover it up after, rather than take a hit on their pride and have some else tell them how to do their job as they know they are still learning and should already know what you have to tell them...
RS components used to be a great company but they now not there stock is on the low side also we had some ups delivered and they must of been friday unit one sparked and stopped working another was not assembled probably great videos keep up the good work
If you own a Chevy say 68 to 88 v8 if your starter solenoid goes out ( starter spins but doesn't engage) you can take the plastic backing off the solenoid, inside is a copper disc flip it over and it will work. They get arch burnt over time.
A relay has a single contact per line, whereas a contactor has two contacts per line, effectively opening the gap twice as much per linear movement for the contactor, breaking any arcing faster.
Thank you very much for this video. I wouldn´t touch this thing even for my workshop at home. Cheap electronics that can switch high power creeps me out a bit.
I always feel really intimidated when I go into shops aimed at the trade. I guess it's because they would know that I'm just some eejit, with a screwdriver.
You're no worse than the majority of people that go in. They're just selling components. The only reason they often say "trade only" is because their premises are charged rates depending on the type of business, so they can't sell to the public. They don't check on business names either. So you could say Siskin's Engineering. I used to just have a cash account that meant you paid for the goods when you bought them and got your invoice/receipt there and then.
Don't be afraid. Half the tradesman (bricklayers, carpenters, electricians, plumbers, ..., you name them) I talked with during the renovation of a house only know what they are doing "because that's how you do it". It is really hard to find one who knows *why* he is really doing something. With bit of reasearch on the internet and a decent amount of common sense, you can pretty much do what most of them do without looking akward. The only thing I feel weird about in shops for the trade is, when I buy one or two of a thing while they usually ask "how many boxes of 50 do you need?" ;)
RS do free next day delivery on any order - many times I've realised I've run out of some little widget like some cable glands or something and had a 69p order delivered to the farm the next morning for free! Saves the embarrassment of looking like a numpty at the counter. Their site is really good for drilling down to the exact size/rating part that's required.
The great thing about the RS Trade Counters was the people staffing those establishments KNEW what they were talking about. The Birmingham RS Trade Counter employed the (locally legendary) Ray Cutler - what Ray didn't know was not worth knowing. Got a problem? ask for Ray. Semis and electromechanical - he was awesome! I think he did evening classes at one of the local Tech. Colleges too - hardly surprising!
Just to note. The #14 NO is the NO held closed for the stop loop of a latching circuit for a 2-wire start/stop. The coil wire would be looped through that contact and a NC pushbutton which is the stop button.
Something I learned as a young man was to always listen to those with experience. Clive, Thanks for sharing your knowledge with us.
Hi BC, the "shunts" you mention are called shading rings and they create a second magnetic pole that is out of phase with the main pole to hold the iron circuit closed as the control voltage passes thru the zero crossing. :)
of course obvious just never had a clue,thanks
I worked at an electrical supply house for some time while at school; there's some very cool capacitor switching accessories for all of the contactors used to deal with. Essentially, it would switch a smaller module that was in parallel with the contactor with a high value resistor in circuit a few milliseconds before switching the actual contactor, which would trickle some current into the capacitors; in turn helping with the inrush that you were discussing.
You know after watching you for a bit, I found my love back for electronics and making my own diy projects. Thank you. Right now I’m working on a digital/analog (red and blue leds).
Used to work on some Irish made ice builder systems that used Omega (or similar name) branded contactors, found to our cost they would randomly stick in, the ice builder used the same condensing units as a milk cooling tank which had priority for the units, someone had used a spare terminal on the contactor to join a couple of wires, one night while making ice the milk tank called for cooling, this contactor didn't drop out and the two cooling signals being on at once caused a latching effect which froze the milk and sheared the paddles off the stirring motors!
That looks to be a very good copy of an older Telemecanique contactor. I have put in many different contactors in my time. There are many different brands but they all look pretty much the same inside.
Keep up the AWESOME work Clive.
When I worked for a major Australian power company, our industrial service techs were told by their leaders (young people, straight out of Uni, with no real world experience), that they wern't allowed to fault find control equipment with the panel live. These were industrial application gas burner controls, sometimes quite complex and the only way of fault finding, in most cases, you needed power on. We have RS Components here in Aust. and they are very good to deal with.
6 years later and still helped me out when it tripped, disassembling it was easy thanks to your video
I love using relays. There's something rather satisfying about the click. Very useful too when you only want to use a small switching voltage to activate larger loads, you could easily make a Hive style Internet heating system for a fraction of the costs, in the £20-30 range instead of £200+
Looks like a clone from a telemecanique contactor, even the colours are right. It would be interesting to see them side by side teared down.
More like KlöMö/Eaton www.maschinensucher.de/pic/large/Schuetz-Klueckner-Moeller-DIL-00M-1/1799559.jpg
That looks like it but wrong colours. Here's a telemecanique:
sigma.octopart.com/10072577/image/Telemecanique-LC1D50B7.jpg
My thoughts exactly
its a rip off of a telemecanique LC1 D09F7 two generations out of date
thats a D50 which is a 50 Amp version
Do you know, Clive, I've been following your channel for over a year now. I went back over some older ones and was surprised how much I'd managed to soak in. So thanks for the education mate.
The knowledge creeps in stealthily. You only realise you have it when you can suddenly understand schematics.
I've started finding the phrase "take it to bits" slipping into my everyday conversations inadvertently. Also been getting urges to just starting take random things apart just to see them.
Don't resist the urge!! Take it to bits!!!!!!!!
For all you wondering (this is AFIR)
11 Common
12 Opener
13 Close
Higher numbers refer to special funtions like timer based contacs
A1/A2 is the coil
Also... we call these "Schütz" in german... to distinct them from relays. They break befor make, thus they can be used to switch phase alignment for i.e. reversing sync. motors.
There are a number of specialized relays of that kind. I.e. the aforementioned reversing of motors, or in conjunction with a thermal overcurrent sensor for breaking the supply to a stalling motor.
Nowadays the majority of these are made to work with PLCs, in my country it is 24V dc
And i want to make this one clear: As voilently as a keep my moneys together, i would never use a chinisium crap relay in something that is supposed to generate (abstraction layer to be inserted here) money.
Siemens, Hager, ABB... that is the way to go. Not cheap but also not prone to fail in less than a decade.
It seems Clive is a never ending encyclopedia of awesome electronic goodness. You sir need the electrical industry's equivalent of a Emmy Award...or two.
Sometimes the quality control is lacking in the little things - like the springs. Springy metal doesn't "just happen" due to the shape. It takes good design and consistent production (heat treating) methods. Spring today... flimsy (or broken) piece of wire tomorrow.
Good video. I've had problems when pricing work. I said it would cost £3500, and this other company said they could do it for £2000. They were using all Chinese parts. Not saying that's wrong, just make life hard for the small firms that are trying to do the right thing.
Talking about a factory when the machinery stops, reminds me of a service call I did some years back. This company was into making "filtration" products, and the input to the machine in question was big rolls of paper, which the machine was supposed to punch large discs out of. The paper production was continuing, and they were running out of places to put it. The controlling hardware on the machine was two boards full of 4000-series CMOS parts, and apparently some power supply issue had taken out a number of chips. The "fixer" on site couldn't quite seem to get a handle on the situation. There was a spare set of boards but they were of a different revision and both needed to be swapped out at once or it wouldn't work. We didn't find that out until the folks showed up who made the machine. I found a bad sensor whose wire ran inside the same conduit as some 220V power, which was probably why it failed and on replacing it they insisted that it be done the same way that it was, so I'm thinking that it didn't last. Perhaps some transient suppression on that particular input would have helped? I remember the guy's jaw dropping when I sketched out a simple crowbar circuit that could be put between the power supply and the machine to protect the boards in the event of future power supply issues. Two of us outside guys plus the factory guy plus the reps from the machine maker and after a couple of days it still wasn't up and running, management was not thrilled...
With regards to selecting the right contactor for a type of load, figures are stated on them AC1 is it's purely resistive rating. AC2 is for wound rotor and secondary resistance motors. AC3 is for starting and running squirrel cage motors (normal duty). AC4 is for inching and or plugging squirrel cage motors (considered severe duty). AC-6a is for switching transformers and other low impedance high inrush loads. And our old friend AC-6b is the capacitive rating usually reserved for switching capacitor banks for power factor correction, and it generally involves early make late break parallel contacts and big wire wound resistors to extend the contact life. For things like car park lighting go with the AC4 rating. PS I use those contactors that you tore down today in older machinery all the time, never had a problem with them, the reason for using them is not the cost, it's because they are exact copies of the old Telemanique contactors that are no longer produced so they fit all the existing mechanical interlocks, and auxiliary contacts, and motor overloads, straight swap and all the electrical and mechanical safety interlocks are maintained, proper job. Cheers, Michael.
DIN rail is so named because of the noise that occurs when the forklift knocks over the rack containing all of your stock of it.
😂
this contactor have better overall quality than any contactor i have ever used in my life (ABB, Schneider, Mitsubishi, fuji electric etc)
Looks just like a Chint contactor from China. I have used Chint and it's pretty decent gear. As for star delta there should always be a mechanical interlock between the contactors to prevent both being engaged at the same time. Some of the old systems didn't have that safety added
Also keep the contactor rating for inductive loads in mind. At a public transportation company we replaced contactors which were used to switch the sodium-vapor lamps at the tram stops. Turns out their combined ballast load was too much for continuous operation and the arcs jumping across the contacts had burned them away over time. There was nothing left of the contact plates.
As an Electrician who works with contactors like this (and even bigger ones) every day...
I NEVER thought about the possibility to cause very nasty shorts when pushing them in with a screwdriver. Thanks for opening my eyes. I will make sure to use an isolated tool from now on.
Pyrrha Nikos when you have a contactor setup with forward/reverse wiring, both contactors better not be drawn down at the same time. Usually you have the coils wired through the NC aux contact so you have electronic interlock
Yeah, that's switching 101, really.
No what I meant was (and not I'm not even sure if that's what he meant in the video) that it's in theory possible to bridge, say, contacts 11 and 13 when jamming a plain old metal screwdriver in there, assuming the contactor is old or broken or cheap or any combination thereof. And since 11 usually is on L1 and 13 is usually on L2... nasty things might happen.
Pyrrha Nikos
that can't/shouldn't happen by design, the manufacturer has to get several type test certificates to sell his stuff and the possibility to
touch live contacts won't help them get these 😉 what Clive meant was simply that you shouldn't press a contactor in by hand if you are not sure that there are others drawn down that could cause trouble by shorting something or mess up the routine of the plc or hardwired controls
That's not what he meant, if you look at a star/delta starter circuit the star point is shorted on the other side of the contactor, but if you bring the delta contactor in at the same time you short all 3 phases through the star point.
Ryan also brings up a good point, in that case you'd short 2 phases instead of all 3.
Plenty of BOOM though - I've seen the aftermath of an engineer thinking "Oh we don't need interlocking contacts she'll be right!"
Christopher Andrews
Exactly what I said! There are many more typical circuits where pushing in a wrong contractor would lead to a fatal error. one example is star/delta of course.
but there is also a serious chance of fucking up the control circuit if you push in random relais or contactors even if you don't blow everything up by shorting something.
shoving a screwdriver up to the contact is unlikely if you don't use brute force to push it in
DIN = Deutsches Institut für Normung - German Institute for Standardization. Bonus Info bit: Many people think it stands for "Deutsche Industrienorm" (German Industry Standard), but that is just not right..
Nahh it's "Do It Yourself" just spelled wrong :-)
I knew someone would be faster than me to post it...
@My Playhouse you sure? I thought it was "National Dyslexic's Association".
WOW Seegal... I always thought it was the latter. Thanks for the real thing.
Free education with Big Clive.
Thanks Clive, you are great.
main difference between contactor =Schütz Relais i learned are:
Double Contacts to better insure safe disconnection (not connection, safety first)
3 main power contacts 1-2 3-4 4-5
and some NO and NC auxiliary contacts for control and feedback "low power" cuircuits.
And also: dont poke it with a stick unless you know 100% what youre doing, a short circuit at 600V and somehundred amps makes go-boom the whole panel.
(edit: typo)
While reading through the log book of an elevator I found an entry that explained the splattered contactor on the table. It said. "Needs new contactor, old contactor refitted. I had a little incident."
Late comment, but FYI: DIN stands for Deutsches Institut für Normung (= German Institute for Standartisation), another common use is Deutsche Industrienorm (= German Industry Standard).
I've seen high pressure sodium floodlighting installations where the PFC capacitors in the fittings have gradually degraded over a couple decades to the point where the low PF has started causing the MCB to keep tripping!
I'd love to do a failure mode analysis on those.
Simple problem, Dremel hand tool variable speed control has become on or off at full speed. Assuming mechanical potentiometer switch...fixable by cleaning maybe or waste of time? Control is 2-10 it kicks in at full speed at 4.
More likely burnt up TRIAC.
Could also be the pot is just worn out. Had a similar problem on my old Ford Pinto's throttle position sensor. The engine idled ok, but died when you pressed the gas pedal. Replaced the "sensor" (pot) and the car ran perfectly again.
Sounds like triac failure. They often fail short circuit.
bigclivedotcom arrr nuts! I will have to return it, it's only 3 months old. Thanks dude love your videos.
My first experience with industrial contactors was at my middle school. The school's baseball field had three light towers that each had about 18,000 watts' worth of lamps (18 lamps x 1,000 watts) totalling 54,000 watts. They were all controlled by just three standard 20-Amp key switches.
One day my physics teacher showed our class the inside of the light control system (I think he was teaching us about Ohm's Law at the time, and was demonstrating methods of controlling large amounts of current with low-current devices). The three switches controlled about 20 or so industrial contactors, which in turn controlled the light towers.
At the time I thought it was cool, but now I think that system might have been a bit over-engineered.
The shunt as you say is actually a shading coil. This gives the coil a magnetic bias so that i can pull in the metal core. If it didnt have shading coils it would not pull in the core.
300,000 subscribers! Well played Clive :)
Ooh! That was sudden. I hadn't even spotted that.
Personally I'm surprised it's that few.
Clive you really are such a knowledgeable guy, thanks for the additional information about the inrush at the end of the video 👍👍
In the power station we often worked on these live in control circuits during fault finding. We used 110v ac contactor coils and if they were faulty they certainly buzzed!
I got to say I always learn something here, and I understand it when I do. If I don't I just ask and someone will take the time to explain. Very cool.
The inrush current is definitely an issue for driving SMPS loads. I had a PC with a 600W PSU connected to a digital lamp timer with a small relay timer inside and within about 20 cycles the relay failed in the closed (on) position. You could still hear the coil energize and de-energize when cycled, but the relay contacts just wouldn't separate.
You can get round that in some situations with a PTC Thermistor. However you have to know how to specify what type etc as too high a temp-co or resistance and your PSU can grey out or go bang etcetera and too low a power rating and the PTC will go pop. You "can" use a PTC all the way up to a 3KW load but personally I would say that's way out on the hairy side. One other option is an inductor. Again it's got to be specified properly as for mains work you really need something with insulation capable of at least 600V (due to back EMF and all sorts of nasties). On top of that you need a low DC resistance to avoid heating etc and the relevant category of insulation temperature (I can never remember which category is which temperature). Or alternatively the "bodge it and scarper" method I use at home is to use a relay capable of 10 or more times the load current. IE a 25A relay for a 600W load. There are mercury wetted contact type heavy duty relays you can get on some surplus sites which are useful for this but personally I'd not use them as I'm a bit paranoid about mercury.
My work uses absurdly huge lighting contactors for the outdoor halide lighting circuits.
These things make the most satisfying KACHUNK when they pull in or drop out.
-Edit: Found a Hopi on flash sale at AliExpress! It's on the way now.
"This is faulty. I don't care that it was my fault that it's now faulty, you should still replace it for free"
Hi Clive, another reason why contractors are used is that the design of how they work clean the contacts as they energise and de-energise you don’t get that with relays
Hey clive, still awesome & informative videos. I've got one suggestion tho: when testing industrial components like switches and contactors, it would be really nice to have an industrial one for comparison. I know ot would be more expensive to buy but in this case i'd like to see into a Müller or Siemens or whatever industrial brand contactor. Maybe they are better built, maybe you can't spot a single difference. Let me know what you think!
It looks very similar to the Schneider ones my work uses for iragation
All of the reasonable to good quality ones will look pretty much identical to this. It's the quality control that's important. I am much more comfortable installing the 110$ Schneider vs the 10$ ebay special.
also looks similar to the ABB contactors we use
Ave recently compared a name brand relay to a cheap chinese relay. There were quite some differences, most notably in the contacts which were build to last a lot longer.
Plus, for the industrial reputable brand relay / contactor you'll get a guarantee of a certain number of cycles, so there is probably some testing going on the factory. Not only does this increase practical reliabilty, it's also probably something you can insure against. No way the insurance is going to pay out if you don't have the parts with the guaranteed number of cycles (or if they find out you went over the number of cycles, although I wouldn't know how they could).
yeah i know it looks pretty decent, would still be cool to be able to show the difference, not only with contactors. Clive should take some more expensive parts to bit :)
and i agree that you can try those out if they are reliable but still, for a factory they cannot afford any downtime, so reputability of the used brands is critical. I'm not saying they are worse, but they could be.
Contactors in HVAC usually fail due to ants (insects) getting in between the contacts, the tell tell sign is a loud BUZZING coming from the contactor. In the south USA this and capacitors are the #1 failure modes of the outside condensing unit.
Be aware of the repairman that says you need a new A/C unit. Always get multiple opinions and do your own research.
Yeah I live in Kansas a.c. went out I know enough to take a look and fall had just hit so cold st night but hot during the day, anyway air shut off so the ants had built there nest up there at night cuz it was warm.
I never seen those, most problem on the HVAC part i work on it having a welded contact
Similar problem in Australia. Our A/C outdoor units get a 6-monthly spray of persistent insecticide to prevent this "problem" (failures arising from such "external sources" are NOT covered by equipment warranties!)
That's what happened to my AC unit! Made a forum post out there because I thought it was super uncommon, guess not: hvac-talk.com/vbb/showthread.php?2235721-Bug-in-contactor-caused-AC-compressor-buzz
I once repaired outdoor equipment and concluded that certain ants were attracted to various power rails. I think 48v DC was one of the popular flavours.
The last place I worked had a unit that used about two dozen VFD's and contactors (rated from 9-30 amps depending what was being driven) all labeled Allen Bradley. I was replacing one failed contactor and when I opened the A-B box, the wrapper and contactor inside were showing another brand, bit made in the came country as printed on the box. So it seems that a major brand name is not a guarantee that they actually made the component.
And yeah, contacts welding closed on a conveyor belt motor causes anxiety in workers that expect the belt to stop when they pause it.
Excellent video...I have had some recent experience having to replace a similar sized contractor that had it coil vaporized after the status light spring contact shorted. Not a great light fuse considering it was for a heat circuit. Fortunately it was not too cold out. Very interesting stuff to “play with”.
You should do a ferrule and crimping vid.
Outside Europe and a few bits of Asia they are not as common.
I would have no trouble using these in the home. Just not in the industrial space.
They are a copy of the old Telemechanique contactors, We have panels full of these things from many years ago that still work perfectly
Always learn something by watching these vids. Thanks Clive.
A rack of these came in the power distribution panel of a machine made in China. One of them melted a terminal. Diagnosing the failure, looks to me like the contact buttons on that one strip were not firmly closing and that there was some arcing on that one leg.
I was thinking of replacing the whole rack with domestic components ($$$$). Thankful to have found this video, confirming reasonably good component quality. So I’ll just get a replacement off of AZ for 12$ and carry-on. Thanks!
The contactor in older Mitsubishi electric r22 air conditioners have a sticker saying “don’t push this button” over the plunger. I always feel like pushing the contactor due to the reverse psychology effect
Usually the contacts are phosphor bronze because it resists welding.
My first "regularly-paying job" post A-Levels was assembling larger versions of these at the Arrow-Hart Plant in Roborough, Plymouth (early 1970's). No "Batch Release" on those - the NCB expected (and got) individual test certificates on every one we assembled. That was the job of the "real" Engineers - us plebs were just the "Assembly Operators"!
NCB specs were actually higher than MIL-STD specs in some places and the individual test certs were also in effect a certificate of conformity.
In my opinion as an electrician if your going to fit one of these cheap devices I'd recommend installing an automatic fire extinguisher in the control panel!
I've seen loads of these cheap contactors from China fail. Im in NZ and everything here has to be approved and certified before its imported. Im sure its the same in most parts of the developed world. I've seen these things on aliexpress for $10 or less with free shipping, but the real deal quality stuff from the local wholesaler will set you back probably $200 if its from Schneider or Allen Bradley etc. Thats because these companies have proper quality control processes and the products are tested and certified. No proper electrician would fit this rubbish and sleep at night.
Another tip for switching high loads is to use multiple contacts. Than you connect one side to pin 1 and bridge to pin 3 and pin 5 and on the other side you connect to pin 6 and bridge to pin 4 and pin 2. This way the resistance should be more equal over the contacts and hopefully prevent burning the contacts (its kind of a dirty trick in my opinion). I have taken many apart, sometimes when the contacts are in a not to bad state I clean them with a fibreglass-pen.
There is a list of utilization categories which divides contactors by their expected usage - a typical AC-7a contactor rated for eg. 40A might won't last long driving a motor rated for 25A, because of contacts burning out. Obviously, it will work at first, but will be prone to failing earlier. Proper category for electric motor might be AC-3 (which is shown on the video), but only on squirrel-cage motors. For mentioned MHL lightning best suited would be AC-5a contactor.
Overrating contactors may be good when you need two or three of them, but in industrial use, when you have hundreds of them in one place, it might cost a lot more - not only higher rated contactors cost more, but they sometimes are bigger in size, which leads to bigger switchgear, consuming more place, and so on. More important is choosing proper contactor for expected usage.
Bit more info: en.wikipedia.org/wiki/Utilization_categories
star-delta and fwd/rev should always be mechanically interlocked. Every time. Contactors can and do weld in. Interlock kits are so cheap. People who omit them are even cheaper.
I'm an automation technician in America for a warehouse that uses high speed sortation equipment from Dematic and we use similar contactors to this but they mostly use 120vac and most PLCs I deal with use 120vac for their inputs and outputs. Not too often do we use 24vdc PLC cards.We do have them in things like out automated HVAC system and our shrink wrap machines but otherwise it's mostly Modicon M340 controllers. I do wonder if those contactors at the place you described where they would trip up the PLC had Transient voltage suppressor resistors built into them? They suppress voltage spikes that can fry PLC inputs... kind of like a fly back diode does.
I really liked the mercury displacement contactors for HID lighting. They would last forever. And they need to, now that they are so hard to get anymore. :(
Mercury switches were amazingly reliable. Fortunately small ones are available in bulk on eBay from China because China.
There are still places to find them other than China... I work in the petroleum industry and they all over the place. Intrinsically safe by design
We use pretty similar contactors (but from Kloeckner Moeller) with the additional contacts on top at work in an old machine for heaters and motors. Yeah, have had stuck contacts, but usually the original ones work pretty okay :). Cool to know about these clones :) and how to take them apart, didn't know that you can :D. This chinese one does actually look quite good :).
For a comparison, look at a Sprecher and Schuh contactor. They are very well made as opposed to this one.
Hi, Clive.. Yes the contactor looks pretty standard construction, all that i would need to check is the contact material.
The spec sheet should state the material used.
A Friend of mine has an industrial oven for paint spraying, and it has two of these contactors in it, one of these and one of its bigger brothers. Both of them were a Pile of **** burning up quickly. I replaced with an RS Solid State Relay much better :) - Good Vid
DIN rail. We call it "Hutschiene". -> hat rail. In a side view it looks like hat. :D
yay I used to buy lots of stuff from RS a long time ago thanks for the lesson its good to take things apart !
There are apparently some things even the Chinese don't like to buy the Chinese version of. Not sure if contactors fall into that category.
condoms
makomk I bought two padded toilet seats from big lots , installed them , sat on one to take a dump... it broke into 3 chunks..
I am not sure how to comment on this.... Epic Shit?
I've rebuilt dozens of high quality Allen-Bradley's. It's a little sketchy, but what are you going to do when production stops, and the managers ... don't want to stock parts? Clipboards ... you gotta hate em.
It's already happened in my industry. The JIT (just in time) and KANBAN approach is only any good if the clipboard muppets know how to actually analyse the lead time data etc. Most of them have clip boards because 1 their memories don't work 2 to have data on so they can quote it to pretend to not be stupid and 3 to do crayon drawings.
Ha Ha Ha, glad to know you share my ... pain.
Looks like a good option for home automation/DIY projects.
Might be less dodgy than doing everything from basic components.
But when things go bang is half the fun!
Heat relay wont stop contactor if you are using screwdriver to hold it in. Lession learned.
Ah, no. The thermal overload breaks the coil circuit. Was there much smoke?
That depends on how it's wired
Does the lesion hurt?
I wonder how many cycles they are rated for? And more importantly how many cycles they will actually survive? Given the average Chinese manufacturer's rather generous assumptions!
Regarding the HID story that is why contactors typically have multiple ratings. I often see 30A contacts rated 24A or less for HID loads.
There's a common cultural idea in China called "face" (as in "saving face") that basically completely justifies straight up lying about something rather than admitting weakness. In the case of so many of these 'straight from the factory' aliexpress and ebay products, this tends to manifest as manufacturers grossly exaggerating ratings of products, usually because they won't admit being weaker than a competing product. This can end up with things being rated an order of magnitude or more higher than actual facts indicate, due to co peting products repeatedly 'out-facing' each other. It's seen as an entirely normal thing in China, but tends to annoy anyone here when they buy a 50,000,000 mAh battery pack and are greatly disappointed.
As a rule of thumb, you have to assume the ratings listed are exaggerated to some degree for any product not quality assurance tested directly and marketed by a western company (although it's been cropping up I've noticed even in recognized brands' products in recent years). I would generally trust industrial components though to a higher degree as the importance of efficiency of the production processes in China would lend itself to well designed factory gear. Then again, you also often end up with the 'reject bin' QA failed products when buying cheap off ebay or aliexpress. I guess buyer beware is the only real safe assumption, that and test the shit out of anything that has the capacity to blow up under normal operating conditions BEFORE using under said conditions.
Good warning about pushing the button. Did that on a 2-speed starter. Big explosion and copper plated arm and face. I was very lucky ...
These look like ripoffs of Telemecanique contactors. Those are much more expensive of course. The auxiliary contact is normally used for feedback to the PLC to let it know that the contactor is currently activated. I've worked with quite a few of those years back.
There are a few that look remarkably similar. If I remember correctly there were some "Square D" ones exactly like this back in the 90's.
By the looks it's a pretty common clone of Schneider contactors, I seen them by many brand names including Tracon, GMV ...
RS components is also present in Germany. I work for a great company which also deals with RS. Great stuff.
That's a clone of the older Telemechanique IEC contactors right down to the colors. Also, I shot first.
yes it do
Chinese bought all the old tooling. Then copied it over an over. Chint another brand using it
and Chana. Also made in India
Just wanted to comment that same thing. And yeah you shot first, fuck George Lukas.
Good you mentioned incandescent and lighting inrush current. It is critical to design for it. Stage/theatrical lighting can run 10,000 amp inrush. Normal industrial switching and contacting won't handle that!
This reminded me of a house fire 100m further up the road. The parents woke up, the man told his wife to go outside while he got the children. But he and the children of 4 and 2.5 never came out again. You try to imagine the dread that mother must have faced but I'm sure it's nowhere near how much she actually felt.
The fire was started by a spark from the fridge thermostat which ignited isolation material. It's a place you never look and it's an appliance you keep running 24/7 for decades. These people weren't marginals who bought some cheap brand or running a meth lab in their kitchen.
Interesting item Clive, at some point in the future maybe you,d discuss the difference between inductive, capacitive and DC loads and how to select the right contactor for the job can be very confusing with all the different manufacturing terminology's that you find in catalogues and the like cheers Clive Sean.
A video on both mechanical and electronic overload relays would be highly appreciated
So would it be devices like these but for lights as mentioned that cause that [Thunk!] sound in movies and TV whenever they show big banks of lights turning on or off like in warehouses and parking garages?
Yes, generally they are bigger in size as they would switch a much higher current load. We use contactors to turn on whole lighting panels for retail stores
Awesome! One of life's mysteries solved then :D
I would have said more of a *Tak!* (but hey, onomatopoeia is subjective). you can also run a line-delay between contactors and a single switch operates any number of arrays (of lights) in sequence. but you'll hear the *tak-tak-tak-tak-tak* like someone rhythmically switching the switches, when it's only actually the one switch, and while it looks cool, it's not just for effect.
About using cheapo components in industrial automation, only do it if you make significant amount of the same machine, if you build 1000 machines, then little savings per every bit and bob can really add up. If you have the time it might be even worth it to tear some sample components down and test it to failure.
If you build one and only machine or in low quantity, take the good components, the little money saved is just not worth the headache.
With reference to the maintenance man at the RS trade counter, not accepting you're judgement on the contactor failure welding in on position. Most see the good advice as intimidating or insulting and it makes them look incompetent, so they normally behave in a dismissive way. Some will get agitated and argue with you, which make you feel bad for interfering with their business. So for this reason its best practice to not give unsolicited advice even if you know they are completely wrong. Speaking from bitter experience...its different if they ask for help, but this never really happens. Most would rather fail and make mistakes and cover it up after, rather than take a hit on their pride and have some else tell them how to do their job as they know they are still learning and should already know what you have to tell them...
RS components used to be a great company but they now not there stock is on the low side
also we had some ups delivered and they must of been friday unit
one sparked and stopped working another was not assembled probably
great videos keep up the good work
RS componants have an Australian (or Asia/Pacific) department too, I''ve ordered Rose Joints & clevises from them & recieved them in the same week.
Bigclive how about some t-sharts "take it to bits" maybe.
If you own a Chevy say 68 to 88 v8 if your starter solenoid goes out ( starter spins but doesn't engage) you can take the plastic backing off the solenoid, inside is a copper disc flip it over and it will work. They get arch burnt over time.
Those linked out coil contacts have caught me out many times!
A relay has a single contact per line, whereas a contactor has two contacts per line, effectively opening the gap twice as much per linear movement for the contactor, breaking any arcing faster.
Thank you very much for this video. I wouldn´t touch this thing even for my workshop at home. Cheap electronics that can switch high power creeps me out a bit.
Definitely right. Awesome tinker grade equipment but you'd be crazy to put them in a liability situation.
Clive can you show the difference between this Chineesium Contactor and a Quality UK/ European one? Same with your other Chinesium tear downs.
You did well to get that back together!
That looks a lot like a Telemecanique contactor
Correct, it seems to be a exact clone, for some reason there is quite a lot Telemecanique (now Schneider) clone stuff available.
Yeah, Schneider Electric nowadays, but I doubt they're as reliable as the real thing.
Schneider is ok, though I'd still rather use Telemecanique
@@kyy7944 Telemechanique and Schneider are the same company
@@kint5ugee I'm aware of that, but the quality of products seem to differ from earlier ones
I seem to remember thermo king having all sorts of contactor / controller issues and also carrier for a short while too.
It looks like the old Eaton contactors
is it just my set up or is the picture slightly darker? really enjot the stuff you do., thanks for your informative and entertaining work.
I like the industrial stuff, could you do more switches and the like?
I disagree Clive.. Allways use Chinese equipment if your a contractor, that way you know you'll be called back about in a few weeks..
I always feel really intimidated when I go into shops aimed at the trade. I guess it's because they would know that I'm just some eejit, with a screwdriver.
You're no worse than the majority of people that go in. They're just selling components. The only reason they often say "trade only" is because their premises are charged rates depending on the type of business, so they can't sell to the public. They don't check on business names either. So you could say Siskin's Engineering. I used to just have a cash account that meant you paid for the goods when you bought them and got your invoice/receipt there and then.
Don't be afraid. Half the tradesman (bricklayers, carpenters, electricians, plumbers, ..., you name them) I talked with during the renovation of a house only know what they are doing "because that's how you do it". It is really hard to find one who knows *why* he is really doing something. With bit of reasearch on the internet and a decent amount of common sense, you can pretty much do what most of them do without looking akward. The only thing I feel weird about in shops for the trade is, when I buy one or two of a thing while they usually ask "how many boxes of 50 do you need?" ;)
RS do free next day delivery on any order - many times I've realised I've run out of some little widget like some cable glands or something and had a 69p order delivered to the farm the next morning for free! Saves the embarrassment of looking like a numpty at the counter. Their site is really good for drilling down to the exact size/rating part that's required.
The great thing about the RS Trade Counters was the people staffing those establishments KNEW what they were talking about. The Birmingham RS Trade Counter employed the (locally legendary) Ray Cutler - what Ray didn't know was not worth knowing. Got a problem? ask for Ray. Semis and electromechanical - he was awesome! I think he did evening classes at one of the local Tech. Colleges too - hardly surprising!
It looks identical with telemecanique small contactors as CA2 DN40 etc... :)
It seems very well designed.
That's probably because it's a copy of something that was designed through long experience.
You are my custom security officer BigC