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No voltage out

Was possibly overloaded , already replaced the diodes and did not help

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Here is a simple test. With engine off apply 12v ac 1 amp to 110v outlet plug on generator. This will energize the field windings and cause the armature to produce dc voltage at the brushes and produce a nice magnet if all is well. If dc voltage is present at comutater, remove 12v ac and start engine to check for output. enjoy

Posted on Nov 30, 2008

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How do I balance the voltage of the 3 phases L1-N, L2-N and L3-N?

If you are measuring unbalanced voltage when the unit is running but unloaded, the problem most likely is in the generator windings. One of the windings could possibly be shorted or failing.

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Start em650z

Capacitors typically fail due to overloading and large current inrushes like HVAC motors compressors etc. Or shorted wiring / windings. Diode? Are you referring to diodes in the exciter? Often fail due to over current

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Getting NO power from the MR2 160/2 Mecc Alte Spa altenator stator. Generator repairman said he didn't find anything wrong using his voltmeter. Measured 6 vac out. I tested caps and they seem good....

There are a few more components to check in the system. From the information provided this is not a Kohler generator as Kohler makes all their own AC alternators under 350KW, seems you may have just a Kohler engine (probably a CH25). Cannot find any info on the voltage regulator which leads me to believe it may be integrated into the main controller. Curious to know who the manufacturer is. If the capacitors are good, try checking the diodes. A volt/ohm meter with a diode check will do. Voltage reading on one side and nothing on the other. If you have no access to a diode check feature, try reading it through a battery NOT SHORTED TO BATTERY hook a meter to a battery and put the diode between one of the leads to the positive, one way will read voltage the other will read open, no voltage, or OL. Look for any fuses or breakers blown / tripped. 6 VAC on the output is about residual voltage meaning voltage the alternator makes without any help from a voltage regulator or field voltage. This usually means the alternator / rotor windings are still good. This alternator is brushless so you could seperately excite this unit via a 12V battery through your field. Look for your exciter field winding, it should have some kind of label on it saying F+ and F-, apply 12V here momentarily on + & - respectively with the unit running and you should see your output voltage spike. This tests the alternator. If this tests ok, then check to make sure your wiring / fuses from the alternator to the controller or voltage regulator (voltage sensing leads) are ok. If all these check ok, it is likely you have a bad voltage regulator.

Jul 15, 2011 | Kohler Power Generators

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Model pm0525312.18 serial 914080230 engine runs good but the voltage drops of from about 125volts to 90 volts when you put on about 1500 watts. does this model have a voltage regulator? what is a bridge...

According to the parts pdf, there is no voltage regulator. Voltage is adjusted by the rpm of the engine. If your have a meter that reads hertz (Hz), you can set the engine rpm by adjusting hertz to 60 cycles (Hz). At 60 cycles the engine is running at about 3600 rpm. Most engines develop their max horsepower at this rpm. If you are loosing power/voltage and the engine speed is not dropping below 3600, than most likely could be problem with capacitor, brushes or diode (bridge diode). The diode converts ac voltage from stator to direct current to power the magnet (rotor). Check for brush wear and test capacitor for value printed on part. It should test with 5% of stated value. Diode can also be easily tested with meter. Good holidays

Dec 05, 2010 | Coleman Powermate Powermate 5000W...

1 Answer

I need a wiring diagram for coleman pm04350001 generator. the 220 recept. is not working and am trying to troubleshoot.

High no-load voltage Capacitor with high capacity
Check and replace. Low no-load voltage Speed to low Check and adjust rpm Faulty rotary diodes Check and replace Breakdown in windings Check winding resistance Capacitor with low capacity Check and replace. Proper no-load but low loaded voltage Capacitor with low capacity Check and replace. if wires are connected start with the Diodes first electronics parts stores will have these in stock as well as cheeper. hope this helps

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1 Answer

I was running two sawzalls on my pmo43350 coleman generator .Now it stopped producing electricity. the engine runs great but no juice to outlets. ithink i overloaded it.

You may have overloaded it, and it may have been damaged.

Check your circuit breakers first. If there was an overload, they should have tripped if overload was long enough in duration and high enough in capacity.

If the breakers are good, then check your diodes and capacitor regulator in the end of the alternator. While you are here, check your brushes as well.

Do you have a manual for your generator?

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1 Answer

I have a Nikota 3500 generator, and I had a shorted circuit in my cabin. Now the generator puts out only 92 to 103 volts. Is there something I can do to fix this myself? Do you think it may have knocked...

Usually a power surge (short) or sometimes an overload will take out the diodes. Like you have suggested I would say that you have just knocked out one... Test them and replace the bad one and you should be good to go.

I hope that this will help you to solve your problem!

Thanks for using Fixya!!


Nov 29, 2009 | Power Generators

1 Answer

I have a North Star Model 5500 belt driven generator. I am using

Hi there,
Yes it is very possible that you blew 1 or more diodes in the rotor when you overrevved the generator. You also likely shorted the MOV devices that go across the diodes as well. What happened is that the over speed of the rotor caused it to make a much higher voltage than it was designed for and something had to give. I'd suggest that you also look at the capacitor that connects to the stator windings (it's a little like a voltage regulator), you've probably exceeded its voltage rating.
This is pretty much why there are governor mechanisms on generators, much more than 20% or so overspeed makes nasty things happen.


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