It can always be something simple. -
Yachts - 07-07-2016
As many of you know I have been having generator issues. When the temperature of the genset box rose I would begin to lose voltage on line 2. If the outside temperature was hot the problem was exacerbated. I changed voltage regulators , and contact boxes. Several people were convinced it was the power head.
Well today while in 100 degree heat the breaker that protected the voltage regulator tripped and would not reset. So improvised with a 10 amp auto fuse.. All of the sudden no matter what temperature the box was I had full voltage. No one had ever heard of one of those breakers going bad but when the breaker got hot it was losing voltage and "flapping" causing the Voltage drop.
I was about to spend 3k on a power head when all it needed was a 20 cent new fuse.
RE: It can always be something simple. -
bikestuff - 07-08-2016
To add to what Marc said....
The thought is that the voltage regulator on the generator is protected by a small 5 amp pop-out breaker. Normally this breaker is supposed to protect the regulator wiring. But in Marc's case, the breaker did not pop out all the way. It was only partially out and was still feeding some noisy voltage to the generator head so the head was providing some power to the coach. Very much a temperature related failure mode. When it was cool the generator provided power, but as it got hotter the breaker began to "rattle" and as a result the regulator would get noisy input voltage and could not do its job properly. Since the breaker was upstream to the regulator, changing the regulator did not help.
The interesting thing about this problem is that Marc experienced a lot of secondary problems. ACs would stop cooling. The transfer switch freaked out multiple times. All this happened only when really hot outside.
Here is the chain.... Voltage Regulator Breaker -> Voltage Regulator -> Generator Head -> Transfer Switch -> AC units.
So the lesson to be learned: I am not sure there is a specific lesson, but me thinks that when you see a voltage drop on one leg of the generator, you should look closely at the output of the regulator and if you see weirdness on the output, be sure to look at the input voltage to be sure it is clean. An oscilloscope would allow you to see the noise caused by the breaker rattle, I am not sure a standard voltmeter would respond quickly enough to see the problem.
Thanks to Marc for staying after this problem. If I ever have a similar issue, I will have a much better idea of where to look.
bill