Genset Adjustment

[egaito]

We've been having frequency issues with the generator, in that the frequency is running a bit high and
making some of the appliances and air conditioner blowers unhappy.

After a lot of reading, I can see that I need to reduce the RPM a bit by adjusting the governor, but am not
quite sure how to go about it. The genset is a Westerbeke 15kw BTD. It does not appear to have an electronic
speed control on it.

I have seen online articles suggesting that the speed control is in the injection pump, and conflicting articles
that indicate I can adjust the governor arm directly.

I identified where the governor arm adjustmen is, with locking mechanisms that restrict movement in
both directions. One of them is a simple bolt with a locking nut, the other is similar with some sort of
plastic cap on it that doesn't readily release itself, and I haven't forced it.

Has anyone ever adjusted their own, or am I digging a hole here by trying to slow it down a bit?

At rest I'm seeing 64.26 hz, which is too high. If I cause every AC on the boat, and the oven to load things
up, I can get it down to 59.3 hz.

Oddly, the voltage seems to be going up with load.....

At near 0 load, I'm getting 122.4v at 59.3 to 59.6 hz. When I load it up, I'm getting 129.5v at 61.4 to about 61.7 hz and briefly
saw as much as 133v.

So, I guess my question is whether or not it's worth trying what appears to be a minor tweak on my own, or just calling someone in before I get myself
into trouble?

Any thoughts?

 

[DCMY #92]

I have a few questions before suggesting a course of action.
Did the governor perform normally (60 Hz a zero and full load) previously?
If so, has anything changed (maintenance, long period with no operation, etc?)

 

[Avenger]

Page 59:

http://westerbeke.com/operator's manual/36856_rev2_15btd_operator_man.pdf

 

[egaito]

I have a few questions before suggesting a course of action.
Did the governor perform normally (60 Hz a zero and full load) previously?
If so, has anything changed (maintenance, long period with no operation, etc?)

I thought I had replied to this, but alas, there's nothing on the thread.

I would call it a bit of a "creep" up in frequency over a couple of years. It always ran at about 62
unloaded, then crept up to 63 at times, according to the old gauge on the panel. We didn't think much
about it since there were no symptoms until we upgraded the galley to "modern" appliances and replaced
the AC units, and subsequently began having trouble.

Reading up on it and testing with a multi-meter has lead us to this point. I hate to call someone out to look at
it if it's a simple adjustment, but of course, I don't want to screw anything up either!

 

[egaito]

Page 59:

http://westerbeke.com/operator's manual/36856_rev2_15btd_operator_man.pdf

This must be a different year...it doesn't look like ours at all.

 

[Avenger]

If you post a pic of the throttle arrangement we can probably figure it out.

 

[GJH]

What did Westerbeke have to say when you contacted them?

 

[egaito]

What did Westerbeke have to say when you contacted them?

I found an engine manual online that I apparently missed because it wasn't a genset manual. It included
how to adjust the engine for generator use, and matches what I observed and surmised about how to
adjust it. It confirmed how I thought things should work and with a little luck, I'll post positive results tomorrow......

 

[egaito]

I found an engine manual online that I apparently missed because it wasn't a genset manual. It included
how to adjust the engine for generator use, and matches what I observed and surmised about how to
adjust it. It confirmed how I thought things should work and with a little luck, I'll post positive results tomorrow......

Adjusting things turned out to be easier than expected, once I was able to positively identify the right bolt to turn.

Finding the right frequency was a bit more complex as we had several items complaining and had to find a "sweet spot"
that keeps everyone happy. The inductive cooktop was the most sensitive, so we focused on getting it to run with several AC unts
running as well. For us, the "magic number" turned out to be about 63.25 hz unloaded, leaving us with 58 heavily loaded. The cooktop
becomes sensitive at that point, but shutting off one AC unit makes it happy again.

Beats the heck out of forcing every AC unit to call for cooling just to make dinner!

From here, I'll look into what appears to be an optional electronic governor control that isn't on our unit.

 

[Avenger]

That's still a fairly significant range. You shouldn't be seeing more than maybe a 2 Hz droop between full load and none.

There may be a speed droop adjustment on the injection pump that can help with that, but I'd need to know what pump you have.

 

[Pascal]

While this will work for a while it seems to be a bandaid on a more serious issue.

I looked at this as we ve had an issue with Charmer's drawer dishwasher which appears to be sensitive to higher freq. (Over 61hz). Both NL and WSBK specs indicate the governor should maintain RPM therefore frequency within 2% as load increases. That's just over 1 Hz.

Your 5hz drop is way too much, that's about 150rpm

General troubleshooting suggestion include dirty filters, air issue or injector pump issue.

 

[davidwigler]

Ed, try taking the fuel return line loose and blow some compressed air through it. Mine had a blockage that caused erratic RPMs under load and I chased fuel supply issues for months before trying that and it solved the problem completely.

 

[egaito]

While this will work for a while it seems to be a bandaid on a more serious issue.

I looked at this as we ve had an issue with Charmer's drawer dishwasher which appears to be sensitive to higher freq. (Over 61hz). Both NL and WSBK specs indicate the governor should maintain RPM therefore frequency within 2% as load increases. That's just over 1 Hz.

Your 5hz drop is way too much, that's about 150rpm

General troubleshooting suggestion include dirty filters, air issue or injector pump issue.

Fuel should be fine...both filters are fresh. I have not serviced the air cleaner recently so that's worth checking.

Thanks,

 

[egaito]

Ed, try taking the fuel return line loose and blow some compressed air through it. Mine had a blockage that caused erratic RPMs under load and I chased fuel supply issues for months before trying that and it solved the problem completely.

That's one I would not have thought of!