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Generator Problems
Posted: Thursday, August 27, 2009 10:19 AM
Joined: 06/06/2008
Posts: 3


I'm having a strange problem with one Northern Lights 65kW generator. Stbd side.

Very rarely, and only at night time, the voltage will spike from 240 up to around 300 volts, and frequency goes from 60hz up to around 64 or higher. Both analog meters go off the scale!

Luckily we have voltage bandwidth monitors which disconnect the supply from the buss (which wakes me up!)
but by the time I get to the engine room it's back to normal.
I've caught it once or twice, to observe the gauges, and the generator is running as normal, temp, speed, DC volts, etc.

Gen runs fine during the day, no matter the load.
I've checked the engine itself and nothing appears out of order.

Quite puzzled, and not able to take shore power here to swap out voltage regulators and test....

Okay, possibly the voltage regulator is faulty, but why does it only happen at night?

Any ideas?

Posted: Thursday, August 27, 2009 7:37 PM
Joined: 04/03/2009
Posts: 12

It sounds like your Voltage Regulator ACC Potentionmeter is breaking down. It is separate unit that is adjustable and connected byway of two wires to the voltage regulator. It is how you set the voltage for the generator. It is only about a $100  part and might be worth replacing. At least it is on my 35KW Onans.
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