Winco generator runs but doesn't generate

[Nick Danger]

Posted this at alt.home.repair, and someone suggested this is the better
place to post

Looking for generator repair advice...
I have a Winco 900-watt Tri-Fuel generator with about 320 hours on it for
home standby use. It's worked well for years - it easily powers everything
in the house except the central AC. During a power outage last night, after
it had been running for about five hours, I turned on the basement light
switch, the lights flashed momentarily and then went out. The only other
load in the basement is a dehumidifier that I always keep running when on
generator power as it helps stabilize the output. I then found that the
breaker for the basement had tripped. We've been in the house over 20 years
and I've never seen that breaker trip. I reset the breaker and then the
entire house went dark. The generator kept right on running with no
noticeable change in sound (i.e. it didn't sound like it was working harder
or easing up). I tried resetting the breakers on the generator, plugged a
light into the outlets on the generator panel - but nothing worked. I turned
it off for a while to see if maybe the problem was heat-related. Still no
luck. It starts up just fine but produces no power. It seems unlikely that
the problem would be a loss of residual magnetism. It gets exercised
regularly, and it was running for five hours when it failed. Does anyone
have any suggestions for things to look for?

btw: After the main power came on, I turned on the breaker for the basement
and everything functioned normally.

tia

 

[Ulysses]

Posted this at alt.home.repair, and someone suggested this is the better
place to post

Looking for generator repair advice...
I have a Winco 900-watt Tri-Fuel generator with about 320 hours on it for
home standby use. It's worked well for years - it easily powers everything
in the house except the central AC. During a power outage last night, after
it had been running for about five hours, I turned on the basement light
switch, the lights flashed momentarily and then went out. The only other
load in the basement is a dehumidifier that I always keep running when on
generator power as it helps stabilize the output. I then found that the
breaker for the basement had tripped. We've been in the house over 20 years
and I've never seen that breaker trip. I reset the breaker and then the
entire house went dark. The generator kept right on running with no
noticeable change in sound (i.e. it didn't sound like it was working harder
or easing up). I tried resetting the breakers on the generator, plugged a
light into the outlets on the generator panel - but nothing worked. I turned
it off for a while to see if maybe the problem was heat-related. Still no
luck. It starts up just fine but produces no power. It seems unlikely that
the problem would be a loss of residual magnetism. It gets exercised
regularly, and it was running for five hours when it failed. Does anyone
have any suggestions for things to look for?

btw: After the main power came on, I turned on the breaker for the basement
and everything functioned normally.

tia

That's a rather small generator for running a whole house! I'd start by
looking for any obvious bad connections going to the AC receptacles on the
genny, then check the circuit breaker(s) for continuity. There may or may
not be a fuse inside the genny and if there is it may be for DC output,
assuming you have that. Next I would check the stator and rotor coils for
any signs of over-heating and possible bad wires. Check the ON/OFF switch
for continuity but that would probably only prevent the engine from running
if it was shorted. There is probably a bridge rectifier inside so I would
check that too--there should be continuity one way and not the other on any
and all adjacent connections and none should be connected to the rectifier
case. Next I would test the diodes on the rotor assuming this is a
brushless design. My guess is that it's either a bad circuit breaker or a
bad diode which was caused by an overload. Also there's probably a
capacitor somewhere (could be located just about anywhere) but I would
expect a low output rather than no output if it was bad.

 

[Nick Danger]

My bad - I meant 9000 watts. It's been a rough week.
If there's a bad breaker somewhere, then it's hidden from view. The
generator has a couple 120-volt outlets (one on each leg of output), a
240-volt outlet (I don't have anything I can test with that), and a big
twist-lock that connects to the cable that goes to the transfer switch.
There are only two breaker switches on the external panel of the generator,
and I reset those multiple times. There are no other breakers between there
and the main panel. Since everything in the house came on normally when the
main power returned, I don't see where there could be any problem in the
breaker box.

I've done some minor repairs on the engine side of the generator. It's easy
to find parts through Google - usually on eBay. But when I look up part
numbers on the generator side, I don't see anything. I'm not afraid to do my
own repairs but I want to know that the part I'm replacing really is bad.
Else, the expenses could add up really quickly. Part of me wants to see the
unit declared unfixable so I can buy a newer bigger one that can drive the
central A/C, since the really big storms always seem to occur on the hottest
humidest night of the year. But the other part of me has to contend with the
economic conditions of 2009 and is a lot more interested in the DIY option.

 

[vaughn]

My bad - I meant 9000 watts. It's been a rough week.
If there's a bad breaker somewhere, then it's hidden from view. The
generator has a couple 120-volt outlets (one on each leg of output), a
240-volt outlet (I don't have anything I can test with that)

Go to Home Depot or Ace Hardware, ETC. and get yourself a cheap neon
tester. They are usually good for 120 or 240, so you can test all three
outlets with it. Then do everything that Ulysses said, plus if your
generator has slip rings, make sure they are clean and that the brushes are
free in their holders and still long enough to make good contact

Part of me wants to see the unit declared unfixable so I can buy a newer
bigger one...

Bigger is not always better. Big generators use lots of fuel, even if
they are lightly loaded. Where I live, electrical outages can run into the
weeks, so my "whole house" generator is only 4 KW. We just practice load
management.

... that can drive the central A/C, since the really big storms always seem
to occur on the hottest humidest night of the year.

That is why we keep a spare $100.00 window unit for our bedroom. I can
install it in five minutes. It is small enough so that the generator can
easily run it, and we have it as a backup in case our central AC breaks.
Much cheaper tha having a huge generator!

But the other part of me has to contend with the economic conditions of
2009 and is a lot more interested in the DIY option.

You and me both! Plus I find myself coping with retirement (or joblessness,
whatever you want to call it).

Regards
Vaughn

 

[Martin Riddle]

Sorry for top posting...

Since its 240v and neither phase works, I would look at the field
connections, the diode bridge, and the exciter transformer if it has
one.

But it could be that the common of the 240v is disconnected, for some
reason. Leading to no output.

I would pop the screws and look inside, it may be visually apparent what
is wrong.

If the lights Flickered, then there was an intermittent connection which
might be easy to spot.
With the vibration, you'd be lucky to find a nut fell off somewhere.

Cheers

 

[Steve Ackman]

Posted this at alt.home.repair, and someone suggested this is the better
place to post

Looking for generator repair advice...
I have a Winco 900-watt Tri-Fuel generator with about 320 hours on it for
home standby use.

Yeah, I knew you meant 9000 watt even before seeing
your other reply.

It's worked well for years - it easily powers everything
in the house except the central AC. During a power outage last night, after
it had been running for about five hours, I turned on the basement light
switch, the lights flashed momentarily and then went out. The only other
load in the basement is a dehumidifier that I always keep running when on
generator power as it helps stabilize the output. I then found that the
breaker for the basement had tripped. We've been in the house over 20 years
and I've never seen that breaker trip. I reset the breaker and then the
entire house went dark. The generator kept right on running with no
noticeable change in sound (i.e. it didn't sound like it was working harder
or easing up). I tried resetting the breakers on the generator, plugged a
light into the outlets on the generator panel - but nothing worked. I turned
it off for a while to see if maybe the problem was heat-related. Still no
luck. It starts up just fine but produces no power. It seems unlikely that
the problem would be a loss of residual magnetism. It gets exercised
regularly, and it was running for five hours when it failed. Does anyone
have any suggestions for things to look for?

btw: After the main power came on, I turned on the breaker for the basement
and everything functioned normally.

When my 5.5 kW generator stopped putting out at
about 8 years of age, I popped the cover containing
the outlets. Probing around with the multimeter with
it running quickly showed where the electrus interuptus
was occurring. It's been a while, but it seems all
that was required was unscrewing a wire, cleaning
things up with emery and putting it back together.

 

[Ulysses]

My bad - I meant 9000 watts. It's been a rough week.
If there's a bad breaker somewhere, then it's hidden from view. The
generator has a couple 120-volt outlets (one on each leg of output), a
240-volt outlet (I don't have anything I can test with that), and a big
twist-lock that connects to the cable that goes to the transfer switch.
There are only two breaker switches on the external panel of the generator,
and I reset those multiple times. There are no other breakers between there
and the main panel. Since everything in the house came on normally when the
main power returned, I don't see where there could be any problem in the
breaker box.

In my experience generators react to short circuits and overloads each in
their own way--one may have melted stator wires, another may lose a diode in
the rotor, and still another may have melted output wiring connectors or an
open circuit breaker. I'm just guessing it was caused by a short because
you said it happened when you turned on a light. Plus this seems to be a
typical cause of failure.

I've done some minor repairs on the engine side of the generator. It's easy
to find parts through Google - usually on eBay. But when I look up part
numbers on the generator side, I don't see anything. I'm not afraid to do my
own repairs but I want to know that the part I'm replacing really is bad.

I have two gennys that are awaiting a final verdict--I have not yet
determined if the rotor or the stator is bad but I've been able to verify
that everything else is OK. So far I have been able to find all the parts
from the manufacturers but in some cases they are not worth the money to
fix. If you are really lucky they might give you the specs for the rotor
and stator coil resistances. On an old Homelite genny I simply replaced the
entire generator head with a new, better one for less than Deere's price for
a new stator. Some day I hope to know everything about generator heads but
to date some things are still a mystery. I can test the coils and measure
the resistance but usually can't verify that it's within range and if they
are different by .5 ohms if that is OK or not. I can test an excitor coil
and determine it's not open or shorted but if the rotor is not getting
excited then it is suspect.

From everything you described it seems very unlikely that the field lost
it's residual magnetism but that doesn't mean it's gettting excited. One
thing you can try is to plug in a voltmeter or expendable appliance (light
bulb perhaps), disconnect the circuit breakers, disconnect it from the
house, and try prodding the governor, raising the rpms and see if it starts
producing. Some generators will. But the voltage could easily go high
enough to cause some damage to applicances. I have a generator (5500 watts,
240V) that does this--it'll start producing at high rpms and maintain normal
voltage output at 3600 rpms AND both lines work and it will easily power
such things as saws, vacuum cleaners, bench grinders, etc but will not power
a 240V pump motor. It also will not connect to my OutBack inverters so I'm
pretty sure the frequency is off but I can't imagine how the two AC lines
could be out of sync. Sounds like a bad capacitor to me but it checks out
OK. If anyone has any suggestions please let me know.

Else, the expenses could add up really quickly. Part of me wants to see the
unit declared unfixable so I can buy a newer bigger one that can drive the
central A/C, since the really big storms always seem to occur on the hottest
humidest night of the year. But the other part of me has to contend with the
economic conditions of 2009 and is a lot more interested in the DIY

option.

I'm not familiar with Winco but every direct-drive generator I've had apart
had a tapered shaft for the rotor and the stator mounts to a plate that is
bolted to the engine in four places. This is all fairly standard. I have
two gennys with Mecc Alte Spa heads (5000W and 6200W) and both have been
trouble-free except when I shorted an output and lost a rotor diode. They
are available on eBay for reasonable amounts of money and if you are happy
with your engine and can't fix the other one this may be an option. You
just need to verify your engine bolt pattern will match and find out which
taper you have on your shaft plus the shaft length. I actually had my 6200W
head attached to a 4 HP engine just to see what it would do. It put out
around 2000 watts. The point is the shaft and bolt pattern was the same as
on a 10 HP engine.

 

[Ulysses]

I thought of another possibility, however it is very unlikely. Check to see
if the rotor is tight and not loose on the shaft. If it's not turning along
with the crankshaft you would get little or no output. Since the bolt that
holds it on should tighten as the engine and rotor turns it probably won't
come loose, but ya never know.