Generator question

[Highbeam]

Don't worry about charging the battery. Just use the generator and if the battery is dead then pull start it. If you use the genny frequently enough then the battery won't die. The running generator will recharge the battery. It really is that simple.

I've used my 11HP Coleman genset to power electric heaters during power outages. It works fine. Plenty of tools too.

I am about to dump the coleman since the gen head is not giving full voltage anymore and it is not worth fixing. The 11HP tecumseh is sure working great, easy to pull start.

 

[tommu56]

Highbeam

have you tried to flash the windings may be the armature lost its magnetization

my old generator had that issue id it set for a couple of months.

tom

 

[Highbeam]

Highbeam

have you tried to flash the windings may be the armature lost its magnetization

my old generator had that issue id it set for a couple of months.

tom

No Tom, I've pulled the brushes and they had plenty of life left. The genset will make full voltage with no load and drop down as I apply load. It won't run my air compressor but will run lights. The engine does not lug at all and frequency stays at 60, just voltage goes down. I also can't weld worth benas with it anymore since the low voltage under load means low amps at the arc.

90 volts at the refrigerator during a power outage is not good.

So you think a reflash would do it?

 

[Highbeam]

Highbeam

have you tried to flash the windings may be the armature lost its magnetization

my old generator had that issue id it set for a couple of months.

tom

No Tom, I've pulled the brushes and they had plenty of life left. The genset will make full voltage with no load and drop down as I apply load. It won't run my air compressor but will run lights. The engine does not lug at all and frequency stays at 60, just voltage goes down. I also can't weld worth benas with it anymore since the low voltage under load means low amps at the arc.

90 volts at the refrigerator during a power outage is not good.

So you think a reflash would do it?

 

[tommu56]

Highbeam

I would try it before trashing it

start it up and put meter on brush holders to see + - stop it and and i use the 12v starting battery and tap the + to + and - to- for a couple of seconds, i finallly ran wires out through the cooling slots so i didn't have to take it apart to flash it

some times i would get a film on slip rings that would stop current to armature (actually it is a rotating field) and i would crocus cloth off the film.

tom

 

[RonMar]

I doubt flashing it will do any good as it is already putting out voltage. Flashing is required when there is not enough residual magnetism in the rotor iron for the generator to self excite, IE: It starts and runs, but no voltage output. This usually happens when it is shut down or runs out of fuel while powering an electrical load. The spindown under load basically neutralizes any residual magnetism left in the rotor from the field coils so there is no rotating field at the next startup to start the power generation process.

If it is putting out less than rated voltage, I would suspect one of the following 3 problems.

1. For a purely harmonically excited generator(no voltage regulator) it probably has a bad rectifyer diode on the full wave bridge rectifyer. This is limiting the current from the harmonic winding being fed back to the field winding via the brushes. Less field current=less output voltage.

2. Some generators of this type also have a series resistor(usually large wire wound) for adjusting the field current and fine tuneing the generator output voltage. IF this has shook loose and it's adjustment has shifted(also not unlikley on a generator) then the voltage could just need an adjustment.

3. For an actively excited generator that uses a voltage regulator(higher end units), there is probably a loose connection or a problem with the voltage regulator circuit.

If you have a picture of the innards(behind control/plug-in panel and where brushes are located) I can probably point you in the right direction to help troubleshoot it. What model number is it?

 

[kraftykeltic]

If the Generator Slip rings are tarnished it will also cause a low voltage/ amperage condition. My generator, coleman 5500 will set for years between uses. But the slip rings have to be cleaned before use to get the voltage out. Something about copper tarnish not being a good conductor, to excite the windings

Tom

 

[Highbeam]

My ill genset is a coleman powermate 5500/6850 surge model. It has the standard coleman genhead on it which has a plastic end bell. I get full voltage with no load, and then as I add electrical load to the generator the voltage goes down and down. I don't even know for sure whether the voltage regulator is in the genhead or in the control panel. The big blue capacitor is in the genhead.

 

[tommu56]

Highbeam

goolge colemanpowermate there is a trouble shooting page for the generators


maby that will help

tom

 

[RonMar]

Well looking at the parts manuals for the 5500W Powermate at the colemanpowermate.com website, it appears that all the powermate series have an Automatic Voltage regulator. If corrosion on the slip rings/limiting current to the rotor is not the problem, then I would suspect a problem in this AVR circuitry.

Good Luck.