older 5kw monarch diesel gen.

Generator runs great, starts easy has 120 volts at outside recepticals shows 240 volts on voltmeter when switched to 240 but there is no voltage at the L1 L2 L3 LO posts. Hertz adjust to 60 with no problem. Have load tested it with two 1500 watt heaters for one hour with no problems. What could the problem be? Any help appreciated I have owned this gen. for more than 20 years and have used it during several hurricane outages using the 120 recepticals for lights and refrigerator. Have never used the line post but would like to use the 240 volts to run my well pump when power is out. I do not know the model no. of the unit as there is no id. tags on it. It has a contactor switch and knob that says contactor closed or open. Where would the contactor be located on this unit? I think it is an older MEP002 but not sure.

Show us some pictures. Of the control box, inside and out. Normally in older sets, you have a reconnection switch, and then a CB, (circuit breaker). The AC meter normally gets its reading from the reconnection switch. You are losing your AC voltage between the switch and CB. So find the CB. Turn it on, (with the gen set TURNED OFF) and check to see if the CB is functioning properly. Test it several times. If it is working correctly, turn the gen set on, and make sure the CB is turned on, mesure if you have AC voltage going into and out of the CB.

Here are the pictures you requested. oldmodelmaker2

Oh baby! Its been almost 50 years since I saw one of those. I don't have books for it, but there should be a wire diagram/schematic on one of the doors. Might be TM's in smokestack. Are there data plates on it? Model numbers? Serial numbers? I know an old fart who MAY have some documentation on it.

The two panel lights, (DS1 and DS2) are missing, but that's not a show stopper. And you can find the right ones easy. They were the same ones used for the last 50 years.

Looks like the Freq transducer leaked at some point in time. If the freq meter works right, then it must have leaked a long time ago, and been replaced. Take a look at the back of the Freq Transducer to find out. Sometimes they leak, and still work.

Just because DS4 doesn't light up, is not reason to think the load terminals are not hot. DS4 is a "press to test", so ALWAYS test it before assuming the CB1 isn't closed.

What about the volt re connection switch? What position is it in? And is it hot, (live).

As you can see, you have a Battle Short switch. Its also possible that the output circuit breaker will not close, due to there being a fault. There is not fault indicator to tell you if there is a fault, so the only way to find out, is try it.

older 5kw monarch diesel gen

Thanks for the reply Guyfang. Where would the output circuit breaker be located? The only circuit breaker I find is the DC breaker. The freq. meter works when I adjust the speed. The volt re connection switch works when I switch it to 240 volts, next position up from where it is at in the photo. Is there supposed to be a light in the push to test button? If so, it doesn't light up when pressed. I will take a look at the frequency transducer when I get a chance. There is a wiring diagram on the panel door for the line post. will try to send a pic. Thanks again Here are better pictures of the two schematics that are on the gen. Use different camera without the flash.

oldmodelmaker2 said:

Thanks for the reply Guyfang. Where would the output circuit breaker be located? (Its someplace behind the control panel. The contactor open/close switch and light, (DS4) on the control panel, control the CB. But the CB is someplace, and I am trying to remember where, its been almost 50 years since I laid hands on one like this. Behind the bulkhead, I think. ) The The only circuit breaker I find is the DC breaker. The freq. meter works when I adjust the speed. The volt re connection switch works (thats because this switch ONLY takes voltage readings, NOT changes the output.) when I switch it to 240 volts, next position up from where it is at in the photo. Is there supposed to be a light in the push to test button? (Yes, there is suposed to be a light bulb in it. If there is not one, I can find a NSN/Part number for one for you. If the top of the light socket is loose and moves around, the light is missing. Unscrew it and see if its just burnt out, or missing.) If so, it doesn't light up when pressed. I will take a look at the frequency transducer when I get a chance. There is a wiring diagram on the panel door for the line post. will try to send a pic. Thanks againView attachment 767050

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Can you get a better picture, without the flash? Its hard to read. And a good one of the schematic?

Hey Guyfang, I got the 240 on line and working fine. Also the 120. There was no DC to the contactor switch. Junpered 24VDC to switch and the contactor closes and opens with the contactor switch. I have 240 across L1 & L3 and 120 across L3 & L0. Also the bulb in the push to test was good. We are ready for the hurricanes..Thanks a bunch from the Florida Modelmaker.

Good job getting this set to work. I would still try and figure out why you have no 24 VDC to the contactor switch. Might be a simple thing you can figure out easy. Don't thank me! You did all the work.

Guy