Mep-017a question

[FireFighterHill]

So I read through the TM trouble shooting and it doesnt answer my question. On one of my Mep-017a's when you put a load to it the hertz drop as low as 48. But when you take off the load the hertz jump and rapidly fluctuate over 60 hz.

When I keep a steady load on it I can keep the hertz at around 58hz by messing with the hertz adjustment knob and the throttle. But when the load cycles on and off that causes the problem to show its self.

I am not overloading the gen as does this when im only trying to pull 1.5kw from the convenience plug. The rpms also fluctuate when this happens. My confusion is if this is a voltage regulator problem or a rheostat problem or something else?

Also the two 15amp fuses behind the control panel, what do they protect?

 

[Carl_in_NH]

Your governor isn't adjusted correctly; look in the 2A042 engine TM - I think the instructions are there. If not, they will be in the genset TM.

 

[FireFighterHill]

You think that will fix the hertz fluctuation?

 

[68impalass]

Carl is correct, your governor is not adjusted properly. Those two fuses you speak of are for the convenience outlets only.

 

[FireFighterHill]

Great, I was worried I was going to have to replace the voltage regulator or some other part. Just for conversations sake, is there anything else that could be causing this I should look at while Im at it?

 

[68impalass]

I guess the only other thing that can cause this is a bad Hz transmitter or gauge. Do you notice the engine speed slowing down or speeding up when the Hz changes? 90% of the time it's the governor "hunting" for that perfect 3600rpm

 

[FireFighterHill]

Not that I recall. I will go through the governor setting procedure when I have a day im not having to watch my son too. Another question is there anyway to tell when these gens were made. There is a plaque on the gen heads one reas "Wisconsin 4-69" and the other "Hercules 7-69" does that refer to month and year? If not can I find out from the serial numbers?

 

[jbk]

the gov. on mine acted the same. it was the gov. rhrottle linkage, the brass bushings were binding. i replaced it with one that had the steel bushings and that corrected it. saturn surplus 15 bucks i think. be sure to tell them you dont wat the brass one. the fuses in side the control box are for the conveniance recept. the data plates on the engine and head are indeed the mounth and year of manuf.

 

[FireFighterHill]

I will check out the bushings when I adjust it. What the best way to lube them? silicone spray? graphite spray?

 

[jbk]

first do you have the steel or bronze bushings? if its the bronze dont bother order the steel. i wasted time on mine and ended up replacing. their should be no bindind at all.

 

[FireFighterHill]

Well im selling them and with as little as the guy is offering im not spending any more money on them. I told him that If I sell them to him for 1k he gets them AS IS. Im just trying to do everything I can so that he wont come back later and tell me ive sold him a lemon.

 

[FireFighterHill]

Well I went out to adjust the governor and lubing them up and adjusting them still hasnt fixed the issue. Its like the generator has a mind of its own.

So I put it under a small load and adjusted the governor. Then when I take the load off the rpms go way up and stay up and so do the HERTZ. When I place the load back onto the generator the rpms drop and the HERTZ drop down in the low 50s and stay there. If I give it throttle by pushing on the linkage the rpms go back up and the hertz go up to almost 65 and stay there. also messing with the voltage adjuster knob does nothing. By the way guys these generators dont have an rpm gauge.

So any ideas on what I should try next? Should I bother swapping Voltage regulators?

 

[Carl_in_NH]

Well, the Hz meter _is_ an RPM indicator; the output frequency is directly related to the engine speed. 60 Hz == 3,600 RPM (provided your meter and transducer work, which it sounds like is true).

Voltage regulation is a seperate degree of freedom that is, to some extent, independant to engine speed (within a reasonable RPM range).

The genset you're talking about has two issues; the voltage regulator isn't working, and the governor is also not functioning. VR issue could be bad connections in the wiring or a blown up regulator. Check that all related wiring is clean and tight. If that looks good, chances are you've got a bad regulator or panel voltage adjustment pot. As for the governor, I'd take it off and go through it looking for something that's binding and see if you can oil it up and get it to work. If not, spring for the $15 and get another one.

 

[FireFighterHill]

If im getting good voltage from the convenience outlet doesn't that mean the VR is good? I swapped known good regulators and the problem was the same. I think it is the pot.

In my messing around ive caused another problem. When I swapped the VR's I must have done something to the field cause now on the voltage indicator it shows nothing, but I still get power at the convenience outlets on both generators.

 

[Carl_in_NH]

What do you mean by 'getting good voltage'? Are you getting a measured 120V (using either internal or external meter) - or are you getting something higher? Higher output voltage that can not be adjusted by the pot typically indicated the output transistor in the regulator that drives the generator field winding has failed shorted. You really need to check this with an instrument like a DVM ($3 at Harbor Freight if you don't have one in your tool box).

The output voltage meter on the panel not working could be either a wire you broke in the metering circuit, or perhaps the output selector switch or the meter phase selector switch is dirty. Try cycling those switches back and forth a few times to see if your panel metering returns to operation.

EDIT: don't turn the generator output configuration switch with the engine running; it would be bad.

 

[FireFighterHill]

I know not to turn the output configuration switch behind the panel while the gen is running, is this also true for the voltage selection switch on the panel? Could the voltage adjusting rheostat cause this problem since it seems not to be working?

 

[Carl_in_NH]

You can turn the switch on the panel at any time; it's just for the metering circuit, and it's intended that it be used while the generator is running.

If you've got voltage at the outlet, yet the meter shows no voltage in any meter selection position then it's the meter circuit that's not working, plain and simple. Whether the VR and pot are working is a seperate issue. Use a DVM connected to the outlet and then check operation of the regulator and pot.

 

[FireFighterHill]

I went out and messed with it again I think ive narrowed it down to a bad governor. It puts out 120v no problem using the voltage adjuster to fine tune, I checked with my digital meter. And as far as the voltage not showing on the panel gauge, well im an idiot it, showed voltage after I moved the voltage selector around. So the only thing not working is the governor.