I had to replace a lot of defective oil pressure sensors on Generac
gensets for that reason. I had forgotten until you brought it up. I
tested for that by disconnecting the terminal from the post on the oil
pressure switch and making sure there was sufficient oil in the
crankcase started the generator. If the engine ran with the oil pressure
switch disconnected then stopped when the wire was shorted to ground,
that indicated a problem. The switch shorted the connection to ground
when oil pressure was lost. There is a time delay allowing oil pressure
to build up and open the connection when proper oil pressure is reached.
With the engine running, use an ohmmeter set to the lowest scale, the
switch should test open with the engine running. I found that the big
old oil pressure switches meant for older automobile oil pressure lights
worked better than the OEM replacement available from Generac
which was a cheap dinky little switch and it was a very common failure
point on their gensets. ^_^
On Friday, September 6, 2013 1:44:01 PM UTC-5, TOM wrote:
n shuts down. -- posted from http://www.homeownershub.com/maintenance/gener
ac-generator-natural-gas-starts-but-won-t-stay-runnin-762399-.htm using Hom
eOwnersHub's Web, RSS and Social Media Interface to home and garden related
Are you sure the gas supply can keep up with the needs of the generator? H
ow old is the unit, when did it last run satisfactorily, etc, etc.
On Friday, September 6, 2013 5:46:31 PM UTC-4, firstname.lastname@example.org wrote:
Could be something simple like that. Or it could be more
serious. I went through diagnosing one last year that also
started up, ran for some number of seconds, maybe 10 - 15 secs
or so, then shut off. As I recall, a few things happen
around that time. One is that upon starting, the ignition
voltage is supplied by the battery, but then after starting,
it switches to being supplied by one generator winding that
serves that purpose. If that winding or associated circuit
is bad, it loses ignition. Also, as I recall, the generator
control looks for normal voltage after start-up. If it doesn't
see it, then it will shut it down.
In the generator I had, it was a bad rotor for sure, and
possibly a bad stator too. I took a look at all the complaints
on Amazon about similar Generacs and concluded it wasn't worth
fixing. That had also been the conclusion of the service guy
who diagnosed it for the neighbor I got it from. Being that it
was only about 5 years old, I thought I might get lucky and be
able to fix it, but it didn't pan out.
I found the Generac service manual online which had good detail
on the various test procedures.
On Friday, September 6, 2013 6:22:19 PM UTC-4, email@example.com wrote:
Also, the unit here had a couple of fuses that were accessible
right at the control panel. Checking them is quick and easy.
As another simple test, if you're comfortable working with AC,
put a test meter on the generator output. If you have 240V
during the time it's running, then you know the generator
section is working. If not, then you know you have bigger problems.
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