Chinese Electrical Circuits

[Randy W]

I'll mention that the double breakers in the U.S. are generally used for 220V circuits (although I have seen them used like this - going to two different 110V circuits). American electrical transmission is two hot 110V lines out of phase, with a third line for neutral. Putting the two hot leads through one double breaker allows for a 220V circuit which can be disconnected with one switch.

 

The Chinese electrical transmission lines have just 2 lines - hot and neutral.

 

My old home (built in 1952, same as me ) in La Porte, TX had 220V wiring throughout the house - the wires were connected to 2 110V breakers. That was apparently up to code in those days. But I sure got a surprise when I went to install an outside security light - I had only turned off ONE of the breakers.

 

This house was wired with 3 conductor wires - 2 hot 110V (and out of phase) conductors and a neutral. Then in connecting to a socket, they would pick off a single hot lead and the neutral - no ground.

[tsap seui]

Randy, my guess is that "double pole breaker" (for lack of a better term is running one appliance with the wires being fed down different conduits to the same appliance. Then again, if it is running two different circuits with a common bar between them...only problem I see if that is the case, if one of those circuits overloads, it is going to have a helluva time popping the breaker because the other side isn't going to want to pop with it, it would just keep sending current downline. When an appliance needs two hot wires run to it in America, the double pole breaker has two hot wires running off of the one common double pole breaker....but the breaker is hooked up to both busses in the panel box...not to the same buss....and you have a heavy neutral wire running back to the neutral bar....same thing for the ground wire (heavier). I'm guessing (since the jumper feeds both side of that breaker) that it is going to possibly the A/C condensor and the alternating that goes on is done in the breaker itself, reducing the need for two buss bars like we have.

 

It is very interesting to me....there IS NO buss bar in that box. The short jumpers along the top ARE the feeds. And they are all run with a small gauge wire. You would think logically, or electrically at least, that they would have used a heavier wire to feed the breakers. In America we have actual heavy metal buss bars that each breaker firmly clamps onto as their feed. Buss bars are thick, can carry many circuits, and will not get hot.

 

I don't think you have any problems really, the box would never pass American code with those small gauge jumpers like that... but...if you were running everything say like in the heat and humidity with the A/C, washing clothes and running the dishwasher along with the lights and such I'd sure go out there and touch those jumpers to see how hot (or not) they are.

 

It will be interesting to see if that double pole breaker is indeed running two separate circuits, whenever you give it a try. That could present a problem should one overload. And it would be very easy for your electrician to put in two separate breakers in its place. Running two separate circuits off of a double pole type breaker would get you a red X from an American inspector and it is not safe, that's why I think that breaker is feeding one appliance...either your A/C condenser, or a hot water tank if you have one instead of the instant hot wall hung type they use in China.

 

At a time that you are running many appliances at one time, including the small "instant hot" type hot water heater if you have that instead of the US type water tank...just feel the breakers and the jumpers....that will be your best way of seeing if there is a problem. Same thing if you have a breaker pop again. Again, I don't think you have any problems, it is just the way things are done there. In the US we overdo some things electrically to be on the safe side. At least you got better breakers put in.

[Randy W]

Yes, exactly! That's really my one concern is the wire gauge being enough to carry the full 63 amp rated load. I don't think there's anything heating up in there, but I can't say that I've stuck my fingers in there to check (except for the old main breaker which WAS heating up).

 

There's no reason in China to run one appliance off of a double breaker, since there's only the one phase. Two wires would carry twice the current - or you cam simply use a larger gauge.

 

The main breaker and this double breaker at the other end are both rated at 63 amps, so a short should trigger one or the other. I agree about single breakers being better, but I'll leave well enough alone. The double breaker DOES feed into two different conduits, so I'm fairly certain that it runs two separate circuits. My guess is that BOTH would break at the same time - this functionality has to be the same in the American circuits, since a single short would have to be enough to throw both sides.

 

For the A/C's, these plug into a single over-size socket at the wall (or floor) unit. The refrigerant line running outside to the compressor also carries the electrical connection. The A/C's seem to carry anywhere from a 5 amp to a 20 amp load from looking at various spec sheets. The water heater runs off of its own compressor, which appears to be identical to the A/C compressors (they're all heat pumps). I've also got a 2000 watt oil filled heater that I only use ONE of the two elements on.

 

We have four separate A/C units, and the water heater - five compressors in all.

 

So I think the saving grace in all this is that the load is fairly light relative to the breaker ratings. The wire gauge doesn't seem to be a factor - but I'd definitely prefer a heavier duty buss.

[chilton747]

I'll mention that the double breakers in the U.S. are generally used for 220V circuits (although I have seen them used like this - going to two different 110V circuits). American electrical transmission is two hot 110V lines out of phase, with a third line for neutral. Putting the two hot leads through one double breaker allows for a 220V circuit which can be disconnected with one switch.

 

The Chinese electrical transmission lines have just 2 lines - hot and neutral.

 

My old home (built in 1952, same as me ) in La Porte, TX had 220V wiring throughout the house - the wires were connected to 2 110V breakers. That was apparently up to code in those days. But I sure got a surprise when I went to install an outside security light - I had only turned off ONE of the breakers.

 

This house was wired with 3 conductor wires - 2 hot 110V (and out of phase) conductors and a neutral. Then in connecting to a socket, they would pick off a single hot lead and the neutral - no ground.

Well you know that since there wasn't any ground then you could make yourself the ground. Just touch both items (lamps or what not) with both hand and whallop you are the ground.

[chilton747]

I would be safer than sorry. Put a clamp meter on the incoming line when you have everything fired up and see what the reading is.

[Randy W]

I would be safer than sorry. Put a clamp meter on the incoming line when you have everything fired up and see what the reading is.

 

 

Well, every time I've thought about buying one, it was always EXPENSIVE and I only had a 1 shot use for it at the time. Maybe I'll come across one priced more in line with my budget out here