generator not producing power

I have a Westerbeke 5.0bcd that I have been using under heavy load for the last several days - 4-5kw. Last night it suddenly stopped producing power. It wasn't heavily loaded at the time, about 2.5kw. It was as though a switch was turned off or a breaker or fuse tripped. I now do not get any voltage at the distribution switch.

I haven't looked at it in any detail yet. There weren't any odd noises or smells that I noticed, and the wiring seems intact.

I don't think there is a breaker or fuse, but am not sure. Really hope it's something like that. But I'm not sure why it would have failed when it did, given that I had reduced load a couple of hours earlier.

The motor starts and runs fine, and doesn't seem to be loaded up.

I'm looking for advice. Will get my voltage meter out when I stop later today and dig deeper but I'm not really familiar with AC generators.

Thanks, Jeff

If installed correctly, there should be a breaker within a few feet of the generator, sometimes inside the enclosure. See if that tripped and diagnose from there: bad breaker, some high load unexpectedly came on that tripped it, ???


David

No breaker. It turns out I'm getting about 7 volts at the genset.

I'm afraid I may have fried it by inadvertently overloading it, although if so it would have been overloaded hours before it failed.

I found the service manual online for my 8kW genset.

Has a good electrical troubleshooting section in it.

Try to find one for yours, if you can't, a close model one might still help.

The 5kW and 8kW use a different method to control voltage (excitation), so troubleshooting is not the same.

To the OP: Sniff around genny back end and try to detect any burnt electrical smell, that would indicate burned windings. Next is to remove the capacitor and test it. Capacitors blow on these and it is an easy fix.

check the capacitor first. you will need to have a meter capable of test them and look for the size(uf) on the body of the cap. they are a high failure item on light towers because people never turn off the load before shutting them down. also a fyi never shut down any generator under load unless its an emergency.

Jeff, if testing the capacitor, in case you are unaware, they maintain a charge so don"t touch the terminals or short to anything or you may get hurt. Google testing a capacitor with a multimeter if you haven't done this before.

With gen off, the capacitor is dead shorted through the windings. It will not retain a charge when unplugged. Still a good idea to bridge the terminals before doing anything.

Ski in NC said:

Capacitors blow on these and it is an easy fix.

Click to expand...

Two times close together we had the same symptoms on our Westerbeke 5.0. Both times it was a capacitor. I believe that there are two buried in the insides and they were not particularly easy to get to. Upside was that no problems now for about 5 years. Knock on wood.


And, yes, bridge the terminals first.

Thanks to all. You guys are awesome. I did find the troubleshooting documentation from Westerbeke online and it confirmed the advice offered here. I removed and tested the capacitor - there's only one on my 1999 genset - and it's dead. Off to find a local replacement.

As much as many of us like to complain about the prices of Westerbeke parts I appreciate an OEM that makes this documentation available and seems to provide ongoing support for their legacy products. Kudos to them.

Motor shops, electrical supply houses, HVAC shops, Grainger, etc often stock caps.

Ski in NC said:

Motor shops, electrical supply houses, HVAC shops, Grainger, etc often stock caps.

Click to expand...

I got one at Grainger. Put it in and all seems good. The replacement cap is a 35 uf(?) and it replaced a 32.5 which appeared to be original. Tech manual calls for 31.5. How concerned should I be? The Grainger guy said it would be OK and my consult with Dr Google was inconclusive.

My plan is to use it moderately until I'm able to stop and source an OEM or exact equivalent. Or should I just not worry about it?

Check your output voltage. The cap uf# will change the output.