Near the beginning of the video you indicated that just because a plug does not have a ground connector, the circuit may still be connected to ground. It's important for people to understand that in almost all residential homes, The ground and neutral are tied together. In that situation, the two prong power cord may still be providing earth ground to the circuit.
I appreciate this video and your teaching style! Very thorough and calmly spoken, yet not boring. AND you've got a ton of videos, so you're a great resource. Thanks!
i know Im asking randomly but does any of you know of a method to log back into an Instagram account?? I was stupid lost my password. I would appreciate any tricks you can offer me.
@Bruno August i really appreciate your reply. I found the site through google and I'm waiting for the hacking stuff atm. Seems to take a while so I will reply here later with my results.
Electrician here > The ground and neutral are ONLY bonded at one point at the main service panel. The ground returns stray current (From s short to the equipment case ) to the neutral point ( where it is bonded) and causes a short circuit that causes the breaker (fuse) OC to open (blow). There is ALSO a wire connected from this point to earth via a ground rod ( many options, called grounding electrode conductor) ) this is ONLY to shunt lightning, period. It has nothing to do with dissipating a short circuit. Why there is a separate neutral and ground is so the return current comes back on the neutral ( it is neutral ONLY to earth is IS a circuit conductor) and does not bleed back on the ground back into the equipment case and then thru you to earth.
In Australia, we have 240 v grid supply. We use a MEN (Multiple Earth Neutral) system, The Neutral which comes into the house is a ground return stake buried deep into the ground every 300 metres or so. This Neutral (common ground) is connected in the meter box to a local house ground, which is a copper stake hammered into the ground. In case of a Neutral link burned out, we have the local ground as a safety measure. We use RCD's (in the USA GFCI's) which has a Neutral and an Active (hot) connection in and out, and from this gadget to any household power point. In case of a leak to ground, there will be a difference between the Neutral and the Active (hot) and the RCD (GFCI) will trip at 15 mA and within say 10 ms. I believe this system is also used in the USA, but perhaps not being compulsory,,, maybe not a lot of people are aware of this system.. Please comment and stay safe.
Differential probes are pricey so, I don't connect my scope to ground. You convinced me that it can be risky. I wonder if it will reduce noise. She is a very sharp oscilloscope, congratulations.
Go check the electrical panel, and look for the neutral from the power company, and tell me where the white (Neutral / earth ground) and bare wires are connected. You will find that they are hooked together.
First most modern devices are double insulated so they do not have a ground prong. Second the ground and neutral are never connected in the device. It would immediately trip a GFCI. Laptop power supplies are isolated. There is no connection to the ground. If you have a device that is mains powered everything inside in the mains voltage side is referenced to the round. The ground prong connected is only to the case/frame, not to the circuits. Its purpose is to cut the power of the phase wire touches the case. Note no device can assume that one of the sides is the neutral. There are systems where there is no neutral or where the plug goes either way, or the socket just may have been mismired.
You know about those "ground adapters," for connecting a 3-prong plug to a 2 contact outlet, and how you're supposed to connect the green wire to a ground? When I worked as a radio/tv engineer for K***-TV (I omit the 3 letters , to protect the guilty, lest an agent of OSHA should read this), we used to call those adapters "ground busters," which enabled us to use the 465 'scope with its chassis "hot."
Simply Put yeah. I’m not really sure how it works outside, ore at least past the main fuse. Which is 36 amps. We do have “fase” (brown) and “zero” (blue) as a single fase 240volts input. And zero being earth potential . About it being really earth I don’t know, cause ground. Here is a green wire with a yellow stripe. And that also grounds out waterline, gas line, heater radiator. But the latter we only have in our bathroom where the shower is, cause that’s code. And where our washing machine is with our central combi gas boiler.
AC works with a "neutral" line at constant potential and a "hot" line that goes above and below the "neutral" line, so I suppose it's not impossible they have your local earth ground connected to the neutral? But not only could they not guarantee that the power company's earth ground is the same as yours even if they were next to each other, they're not and there's a huge resistive path between theirs and yours so you'd have a kilometers-long ground loop. That can't be it. But I can't think of anything else that even begins to explain it.
the neutral line is connected to ground (yellow-green) 220vac (Europe, Greece) inside the box where the power meter is. from there to each houses physical ground. (usually about 2 meter long poles underground )
I understand and appreciate the point of this video, but one thing is unclear to me. At about 3:55 you discuss cutting off all but the earth ground pin from an old extension cord so that it is safe to probe. Could you explain what we are doing with the resultant measurement?
bro they wouldn’t give me one wither so i had to use my wallet also. had to return it sadly because i realized i had higher priorities like paying to fix my vision
My power supply earth-ground terminal shows a few ohms resistance to my soldering iron, as expected. But both the positive and negative terminals show 45 MΩ (megaohms) to that same soldering iron -- was hoping they would show as an open loop instead like yours did in this video. Is it fair to say my power supply doesn't have proper isolation from earth ground and my oscilloscope is at risk.. or is 45MΩ enough resistance to protect it?
I assume that's either the actual resistance of "the ground" or your power supply does have some sort of humongous resistor connecting negative to ground just in case. I've seen some diagrams where there is a huge resistor connecting the AC neutral and DC ground on either side of a transformer, too. But 45 megaohm would need 45 kilovolt to produce even 1 milliamp, so just don't let it get hit by lightning and you're fine.
So I suppose running a 1 inch wire from the outlet to the metal outlet box does not qualify as an appropriate earth ground 🤔. I dont want to run ground wires through my 80 year old walls 😢. And I certainly do not want to use my scope in the bathroom which is the only room in the house with a proper earth ground 🤣. I might use one of those 3 prong > 2 prong converters with the ground hanging off and run my own conduit outside into the actual ground 🤣. I'm not crazy leave me alone.
Can’t see a thing you are doing in your tests with the soldering iron station because your arms are in the way. Have no idea what you are connecting or not connecting. Explanation’s are nice but video could have been less choppy with better visibility of what you are doing.
I would assume it would work fine, but I wouldn't want to guarantee it because oscilloscopes are precise pieces of equipment and might rely on earth ground as a super-stable reference.
My Hantek came with a 2 pin plug, no ground pin. I guess that is because the scope is double isolated, and as such, it is wrong to earth a double isolated electrical equipment. However the scope grid input doesn't show the double isolated sign. I used my own 3 pin plug because I use RCD's (in the USA GFCI's) on all of my circuits,,, and they trip with a leakage of 15 mA in about 10 ms. On the equipment tested at 240 vac I use an isolating transformer.... I would like some comments as what is done in the USA. In Australia, on all new homes it is required to have a safety switch (RCD / GFCI). to eliminate the risk of electrocution. How about the USA ?
Near the beginning of the video you indicated that just because a plug does not have a ground connector, the circuit may still be connected to ground. It's important for people to understand that in almost all residential homes, The ground and neutral are tied together. In that situation, the two prong power cord may still be providing earth ground to the circuit.
The best explaing video regards to probing and earth ground i have ever seen. Thanks!
I appreciate this video and your teaching style! Very thorough and calmly spoken, yet not boring. AND you've got a ton of videos, so you're a great resource. Thanks!
i know Im asking randomly but does any of you know of a method to log back into an Instagram account??
I was stupid lost my password. I would appreciate any tricks you can offer me.
@Elliott Blaine instablaster :)
@Bruno August i really appreciate your reply. I found the site through google and I'm waiting for the hacking stuff atm.
Seems to take a while so I will reply here later with my results.
@Bruno August it did the trick and I actually got access to my account again. I am so happy!
Thank you so much you saved my ass !
@Elliott Blaine glad I could help :D
You cleared up so much for beginners. It was simply put thanks man
Electrician here > The ground and neutral are ONLY bonded at one point at the main service panel. The ground returns stray current (From s short to the equipment case ) to the neutral point ( where it is bonded) and causes a short circuit that causes the breaker (fuse) OC to open (blow). There is ALSO a wire connected from this point to earth via a ground rod ( many options, called grounding electrode conductor) ) this is ONLY to shunt lightning, period. It has nothing to do with dissipating a short circuit. Why there is a separate neutral and ground is so the return current comes back on the neutral ( it is neutral ONLY to earth is IS a circuit conductor) and does not bleed back on the ground back into the equipment case and then thru you to earth.
Great video. Thankyou. Love the hairdryer and shower analogy. As you say, don’t be that person 🤣
wow Very informative you Just deciphered so much of my myths. one session with a wise man worths more than reading a book. much appreciated
Very well put!! I understood! Thanks for the information and dedication.
In Australia, we have 240 v grid supply. We use a MEN (Multiple Earth Neutral) system, The Neutral which comes into the house is a ground return stake buried deep into the ground every 300 metres or so. This Neutral (common ground) is connected in the meter box to a local house ground, which is a copper stake hammered into the ground. In case of a Neutral link burned out, we have the local ground as a safety measure. We use RCD's (in the USA GFCI's) which has a Neutral and an Active (hot) connection in and out, and from this gadget to any household power point. In case of a leak to ground, there will be a difference between the Neutral and the Active (hot) and the RCD (GFCI) will trip at 15 mA and within say 10 ms. I believe this system is also used in the USA, but perhaps not being compulsory,,, maybe not a lot of people are aware of this system.. Please comment and stay safe.
Excellent video. Let me know exactly what I was looking for. Thank you!
Differential probes are pricey so, I don't connect my scope to ground. You convinced me that it can be risky. I wonder if it will reduce noise. She is a very sharp oscilloscope, congratulations.
Go check the electrical panel, and look for the neutral from the power company, and tell me where the white (Neutral / earth ground) and bare wires are connected. You will find that they are hooked together.
Your gnd clip on the probe is earth grounded. When it touches any point in your circuit you are grounding that point.
First most modern devices are double insulated so they do not have a ground prong. Second the ground and neutral are never connected in the device. It would immediately trip a GFCI.
Laptop power supplies are isolated. There is no connection to the ground.
If you have a device that is mains powered everything inside in the mains voltage side is referenced to the round. The ground prong connected is only to the case/frame, not to the circuits. Its purpose is to cut the power of the phase wire touches the case.
Note no device can assume that one of the sides is the neutral. There are systems where there is no neutral or where the plug goes either way, or the socket just may have been mismired.
Awesome! as usual.
What about a DC circuit running on a battery. Would you connect the alligator to the negative.???
great video simply Put, thank you
Cool beans!
You know about those "ground adapters," for connecting a 3-prong plug to a 2 contact outlet, and how you're supposed to connect the green wire to a ground? When I worked as a radio/tv engineer for K***-TV (I omit the 3 letters , to protect the guilty, lest an agent of OSHA should read this), we used to call those adapters "ground busters," which enabled us to use the 465 'scope with its chassis "hot."
Thank you Sir 🙏
Thank you so much.
Whenever you use a hair-dryer in the shower, it's advisable to wear rubber gloves :).
remember when James Bond throws a fan into the villain's bath( against DrNO) ah ah ah
We still have ungrounded wall plugs in the wall here. Europe that is. Funny stuff, grounded wall plugs are in the bathroom and washing room.
That's actually horrifying. Hopefully they at least have some of the fastest-acting fuses in the world so you only die a little bit.
Simply Put yeah. I’m not really sure how it works outside, ore at least past the main fuse. Which is 36 amps.
We do have “fase” (brown) and “zero” (blue) as a single fase 240volts input. And zero being earth potential . About it being really earth I don’t know, cause ground. Here is a green wire with a yellow stripe. And that also grounds out waterline, gas line, heater radiator. But the latter we only have in our bathroom where the shower is, cause that’s code. And where our washing machine is with our central combi gas boiler.
AC works with a "neutral" line at constant potential and a "hot" line that goes above and below the "neutral" line, so I suppose it's not impossible they have your local earth ground connected to the neutral? But not only could they not guarantee that the power company's earth ground is the same as yours even if they were next to each other, they're not and there's a huge resistive path between theirs and yours so you'd have a kilometers-long ground loop. That can't be it. But I can't think of anything else that even begins to explain it.
Simply Put I’m gonna dig into this. This made me curious now.
the neutral line is connected to ground (yellow-green) 220vac (Europe, Greece)
inside the box where the power meter is. from there to each houses physical ground.
(usually about 2 meter long poles underground )
Good Explanation! !
I understand and appreciate the point of this video, but one thing is unclear to me. At about 3:55 you discuss cutting off all but the earth ground pin from an old extension cord so that it is safe to probe. Could you explain what we are doing with the resultant measurement?
Brilliant!
well after the other videos i have watched. this one makes sense.
I feel that soldering iron example. Recently my tech was soldering on high voltage caps. Turns out they weren't discharged. Oops.
bro they wouldn’t give me one wither so i had to use my wallet also. had to return it sadly because i realized i had higher priorities like paying to fix my vision
After 5 minutes, I totally lost you. Very confusing vid!
Now consider the anti-static safety you are supposed to use, if it is not earth grounded it isn't effective
Anti-static safety equipment typically has(or is supposed to have) a 1 meg ohm resistor in series between the bracelet, mat, etc and earth ground.
My power supply earth-ground terminal shows a few ohms resistance to my soldering iron, as expected. But both the positive and negative terminals show 45 MΩ (megaohms) to that same soldering iron -- was hoping they would show as an open loop instead like yours did in this video. Is it fair to say my power supply doesn't have proper isolation from earth ground and my oscilloscope is at risk.. or is 45MΩ enough resistance to protect it?
I assume that's either the actual resistance of "the ground" or your power supply does have some sort of humongous resistor connecting negative to ground just in case. I've seen some diagrams where there is a huge resistor connecting the AC neutral and DC ground on either side of a transformer, too. But 45 megaohm would need 45 kilovolt to produce even 1 milliamp, so just don't let it get hit by lightning and you're fine.
@@simplyput2796 Thanks for taking the time to answer and put my mind at ease! Cheers
So I suppose running a 1 inch wire from the outlet to the metal outlet box does not qualify as an appropriate earth ground 🤔. I dont want to run ground wires through my 80 year old walls 😢. And I certainly do not want to use my scope in the bathroom which is the only room in the house with a proper earth ground 🤣. I might use one of those 3 prong > 2 prong converters with the ground hanging off and run my own conduit outside into the actual ground 🤣.
I'm not crazy leave me alone.
Can’t see a thing you are doing in your tests with the soldering iron station because your arms are in the way. Have no idea what you are connecting or not connecting. Explanation’s are nice but video could have been less choppy with better visibility of what you are doing.
Some misstatements here but fairly good information.
Neutral bond can be problematic. As you called out that they were “shorted” together it’s technically a neutral bond so earth is found via neutral.
What if I don't connect my oscilloscopes ground (3rd pin in the plug) to the earth ground ....
I would assume it would work fine, but I wouldn't want to guarantee it because oscilloscopes are precise pieces of equipment and might rely on earth ground as a super-stable reference.
@@simplyput2796 Thank you for your quick reply ... I thought so too ... Your channel is a great place on youtube .... 😊😊
My Hantek came with a 2 pin plug, no ground pin. I guess that is because the scope is double isolated, and as such, it is wrong to earth a double isolated electrical equipment. However the scope grid input doesn't show the double isolated sign. I used my own 3 pin plug because I use RCD's (in the USA GFCI's) on all of my circuits,,, and they trip with a leakage of 15 mA in about 10 ms. On the equipment tested at 240 vac I use an isolating transformer.... I would like some comments as what is done in the USA. In Australia, on all new homes it is required to have a safety switch (RCD / GFCI). to eliminate the risk of electrocution. How about the USA ?
Usa added gfi near water years ago, and now has afi
Arc fault interrupt. To all circuits in new homes.
the editing is horrible with this constant flash switching cutting frames yikes.
Yeah, math sucks!
What happens if I have no ground in my home 😬