Bringing an old generator back to life

[aczlan]

What are you getting for exitation voltage? Sounds like you have an open circuit somewhere.

Or he let it idle and fried the voltage regulator.
The MEP002 and MEP003 generators should NEVER, EVER, EVER, EVER be idled
At idle, the voltage regular WILL fry itself VERY QUICKLY trying to get the genset to make 120VAC when it is only spinning fast enough to make 60VAC

Aaron Z

 

[Bob Rooks]

How can you get them to idle? My DJB and DJC wind right up to 1,800 (60Hz) r/m?

 

[aczlan]

How can you get them to idle? My DJB and DJC wind right up to 1,800 (60Hz) r/m?

There is a throttle control on the MEP gensets with a locking mechanism that you use to set the governor. It should be set to ~62hz when unloaded and then LEFT ALONE.

Aaron Z

 

[Breen]

Did you ground it? The excess current has got to go somewhere.

 

[sewerzuk]

Woody, by FAR the most common no-power problem I have seen with the MEP-002a and -003a is improper starting; releasing the start switch too early prevents the generator from exciting, and it will not generate power.

When you start the set, you need to continue to hold the start switch in the start position for 10-15 seconds AFTER the engine has started. A speed switch will disengage the starter (unless you have the throttle set to idle) and prevent it from grinding.
Once you have the set running, you should set the throttle to 60 hz and leave it there. Running the set at low RPM will eventually burn up one of the power transistors on the voltage regulator and also result in a zero output.
If you are already starting the set correctly, do me a favor and turn the switch to start (with the engine running) and tell me what the meters do...

 

[woody2956]

sewerzuk.....wow...that worked every time.....thank you......now a new problem....in the convience outlet I plugged in a small hair dryer....and the governor took 30 sec to recover and when the dryer was shut off the engine rpm's went wat up and the engine slowly settled back 60 hertz,,,,the voltage was easy to regulate....as was the hertz untill a load was applied.....thank you again for your help........

 

[sewerzuk]

It should take nowhere near that long to recover...since it stayed low and then stayed high, I suspect sticky linkage. Try cleaning/lube on all of the linkage on the injection pump. Make sure to get some good lubricant inside all of the pivot points. Your generator should have had no problem with a small hair dryer; I believe they are designed for a 2hz droop from zero to full load.
After the linkage is repaired, try loading it with something larger...let me know what kind of frequency droop you see...

 

[woody2956]

sewerzuk....finally got back to the 003 and found the governor linkage was binding on the side of the fuel shut off solenoid.....I bent it away just enough to clear.....starts easier and responds much quicker....my next task is to find something to load it down in order to check it under something near a full load.....any thoughts of what might work? I thought maybe hook it to the house and hit it with the water heater....I am open to any and all ideas....thank you again for all your help....woody

 

[sewerzuk]

sewerzuk....finally got back to the 003 and found the governor linkage was binding on the side of the fuel shut off solenoid.....I bent it away just enough to clear.....starts easier and responds much quicker....my next task is to find something to load it down in order to check it under something near a full load.....any thoughts of what might work? I thought maybe hook it to the house and hit it with the water heater....I am open to any and all ideas....thank you again for all your help....woody

Glad to hear you sorted out the linkage issue...
Before I had my load bank, I loaded my sets with all sorts of stuff. Hot water heaters, clothes dryers, ovens, ranges, and other household appliances work well, but they do cycle on and off. That's fine for a short load test, but if your goal is something extended then it is best to find more constant loads. Halogen lights and space heaters are good because they are always on. If the set is powering your house, you can usually put a pretty good load on it by turning on all of the lights in the house, the TV(s), etc.

 

[Bob Rooks]

Side question:
I just acquired a DJB two cylinder and it needs a CB-4 circuit breaker (it was missing).
The parts book calls for a 320-1706-14 but I'm told the number changed to 320-1706-04, which I can't find anywhere (neither of them). This is a three lead breaker. Does anyone know of a substitute that can be used in place of the Onan part, or a good work-around?