Generator tripping 240v circuit breaker

[hammick]

Removed the tab on the outlet and the generator runs and puts out power like new.

[Sunking]

Well Sunking I have to disagree. First I am no electrician but I have a lot of wiring experience. Two black wires doesn't always mean L1 and L2. There are often at least four outlets on a 20a or 15a circuit. Two black wires on all but the last outlet and the tab is intact. One black travels to the next outlet.

That would be 6-wires (2 black, 2 white, 2 green).You would not break the TAB at any daisy chained outlet in the scenario you just mentioned. The last outlet would only have 3 wires of L>N>G. You had a dedicated outlet with 4-wires making it 2 dedicated circuits. One circuit on L1, and another on L2.

[hammick]

Well Sunking I have to disagree. First I am no electrician but I have a lot of wiring experience. Two black wires doesn't always mean L1 and L2. There are often at least four outlets on a 20a or 15a circuit. Two black wires on all but the last outlet and the tab is intact. One black travels to the next outlet.

[Logan005]

I know when wiring a half duplex switched outlet in homes, I break the tab, to split the receptacle. seems designers don't do it as much these days. All 3 bedrooms in our house are wired like this.

[Sunking]

As there are a few people on the forum from other parts of the world, those wire colors and configurations may not apply. So make sure you know what you are doing.

Well Hammick is in the USA. This being a DIY site means most have no clue what they are doing. If they did, they would not be here in the first place.

[Bala]

That is inexperience and lack knowledge of electrical codes and color codes. Black = Hot, White = Neutral, Green = Ground...

I am not criticizing you, just pointing out any electrician who sees two black wires automatically knows what he has (L1 and L2). So when you seen 2-Black, 1-White, and 1-Green should tell you immediately you have a 4-wire 240/120 circuit. It is what you did not know that got you into trouble.

As there are a few people on the forum from other parts of the world, those wire colors and configurations may not apply. So make sure you know what you are doing.

For Australia we have only 240V for households, small gensets. Only 3 wires know as active neutral and earth. Active and neutral have a few color variants. Earth is always green. White is not used for AC here.

[Sunking]

Both wires were black and it didn't even dawn on me they were separate legs..

That is inexperience and lack knowledge of electrical codes and color codes. Black = Hot, White = Neutral, Green = Ground...

I am not criticizing you, just pointing out any electrician who sees two black wires automatically knows what he has (L1 and L2). So when you seen 2-Black, 1-White, and 1-Green should tell you immediately you have a 4-wire 240/120 circuit. It is what you did not know that got you into trouble.

I am glad you figured it out, and thankful it was just a generator output and not utility power. If it had been utility power a tripped breaker would have been the least of your problems. You would have had an ARC FLASH to deal with. Which brings us back to your batteries again. Make that mistake with them and you will be introduced to Arc Flash 101. With Arc Flash 101 there are only two grades the teacher issues. One is nice and Adorable, and the other is a big fat Fire

[hammick]

Both wires were black and it didn't even dawn on me they were separate legs. I guess the fact that there is only one 120v duplex outlet on the genny should have clued me in. I didn't notice the tab removed on the outlet I replaced. The other 120v outlet is a 30a RV plug.

[Sunking]

I kept the wiring exactly as it was. Just didn't know I needed to remove the tab. .

Unless you have experience working with it, you would likely not know unless someone with experience pointed it out. You are lucky you got recept with a Link.

Let it be a lesson and remember when you are running a circuit with both L1 and L2 something is different about it you need to pay attention too. Generally speaking a circuit with both L1 and L2 are 240 volt circuits.

240 VAC circuits comes in 2-Flavors, 3-wire and 4-wire.

• 3-Wire circuits are L1, L2, and G and strictly for 240 loads only.
• 4-Wire Circuits are L1, L2, N, & G The load is both 240 volt and 120 volt. Good examples are Ovens, Cooktops, and Dryers. For example a electric dryer heating elements are 240 volts, while the motors and controls are 120 volt.

Tip for anyone when you need to run a 240 VAC circuit, run 4-wires. Your device may only need L1, L2, and G initially, but some time in the future you may need a Neutral to derive 120 volts. Nothing prevents you from running the 4th wire, just tape it up so it cannot short anything out. If for some reason in the future if you need the 4th wire is a lot easier to run it now vs later. Only down side is the 4th wire cost more initially, but is an Ace in the hole if needed.

[hammick]

I replaced the cracked 120v outlet with a 120v outlet I bought at Lowes. I kept the wiring exactly as it was. Just didn't know I needed to remove the tab. Above my pay grade to know why the 240v breaker was the only circuit tripping.

I won't be able to remove the tab and start it up until Sunday but I suspect it will work just fine.

Lesson learned and I didn't get lit up.

[Sunking]

Keep reading the posts Dereck.
He replaced a broken duplex on the genny he was reconditioning.

DOH! OK does not change much, he did not know how to wire a Multiwire. more specifically to break the LINK.

[inetdog]

I would call that factory wiring that is done properly.
Multiwire receptacles are permitted but seldom used. Hammick indicated he found the problem to be the TAB that connects both halves of the duplex receptacle together. That tells me he had to wire it himself and ran 4-wire circuit to it. If the LINK as it is technically called had been removed it would have worked. But with the LINK in I would certainly hope the genny breaker operated. as it had a Bolted Line to Line fault.

Keep reading the posts Dereck.
He replaced a broken duplex on the genny he was reconditioning.

PS: It is possible that there was a blown single pole CB that he did not tell us about that allowed one phase to successfully power the two receptacles with the link still in place.
Still some wiring details missing.

[Sunking]

Would you call a duplex receptacle mounted on the genny house wiring?.

I would call that factory wiring that is done properly.

Multiwire receptacles are permitted but seldom used. Hammick indicated he found the problem to be the TAB that connects both halves of the duplex receptacle together. That tells me he had to wire it himself and ran 4-wire circuit to it. If the LINK as it is technically called had been removed it would have worked. But with the LINK in I would certainly hope the genny breaker operated. as it had a Bolted Line to Line fault.

NEC is very specific about Multiwire circuits as they requires special attention. It is covered in 210.4 and 240.15 (B)(1). In short requires that a Ganged Dual Circuit breaker used, and can serve only Line to Neutral loads.

Having said all that, I am happy Hammick found the problem and I hope he understands what happened. So Hammic if you want to use a Multiwire circuit you need a special circuit breaker for them and labeled as Multwire. They require 4-wires L1, L2, N, & G. Don't forget to TAKE THE DAMN LINK OUT OR BOOM as you discovered.

[inetdog]

Not in a house premises wiring. Multi-wire outlets are very rare and have very strict rules.

Would you call a duplex receptacle mounted on the genny house wiring? If the OP is talking about a house outlet cord connected to the 240V out of the genny, I agree with you.
My genny has one 30A 120 twist lock, two 20A duplex receptacles on opposite phases, and one 20A 240 twist lock.
All have their own compact CBs.

[Sunking]

I am guessing to maximize the output capacity, most generators I have seen run specific power to each plug.

Not in a house premises wiring. Multi-wire outlets are very rare and have very strict rules.