The generator trips one pole /30 amp generator breaker even when the transfer switches are off

generator

I have a problem with my newly purchased home with a generator transfer switch previously installed and the generator left by the owners, knowing that winter was on its way I started the generator to make sure I had 240 volts and I did, so chase to winter, the power is out so I start the generator and put my transfer switch to generator from the off position on the transfer switch and it pops the 30 amp circuit breaker on the generator so I could only power up the 120 v circuits on the other generator leg that was live. I disconnect the red, black, and the neutral from the generator to the house neutral and the transfer switch leads and I read 120 volts from the black feed to the generator neutral and 120 volts from the red feed to the generator neutral and 240 volts between the red and black generator leads as would be expected but when I measure the black generator lead to the house neutral I get 0 volts and from the red generator lead to the house neutral I get 240 volts and the red generator lead is the same one popping the 30 amp generator circuit, I do not see anything that could be back feeding the house neutral, even with the main off it is popping the 30 amp generator circuit, when it does this the generator almost bogs down so much that it almost stops but the circuit trips before that happens, like there is a huge load on it just on the red lead side of the generator can anyone help, I am pretty comfortable with electricity having previously wiring a transfer switch at my previous home with no problems, the only thing different is the generator ground is wired back to the house ground could this be the problem?

Best Answer

You said:

I disconnect the red, black, and the neutral from the generator to the house neutral and the transfer switch leads and I read 120 volts from the black feed to the generator neutral and 120 volts from the red feed to the generator neutral and 240 volts between the red and black generator leads as would be expected but when I measure the black generator lead to the house neutral I get 0 volts and from the red generator lead to the house neutral I get 240 volts and the red generator lead is the same one popping the 30 amp generator circuit

If the black generator lead to the house neutral is 0 volts then someone has connected them together somewhere. That is why the red lead to the house neutral is 240 volts.

It sounds like something is seriously mis-wired here. Take apart what you have and post some pictures or better yet trace every wire and draw a diagram of what you have and post that with the pictures.