Cummins EFC Governor

Cummins/Onan Air Cooled & Liquid Cooled standby generator troubleshooting and repair questions
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KevinSalyer
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Thu Dec 20, 2018 2:41 am

Hello, I've got problem with a Cummins generator. It seems like the engine operates below idle speed. How can I solve this?

It is a 120kW Cummins bought years ago. The warranty is expired. There is still problem here.

When I try to upload my pic, it says "It was not possible to determine the dimensions of the image. Please verify that the URL you entered is correct." but I uploaded it directly from my PC.
Chris
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Thu Dec 20, 2018 7:17 am

Is the image in a strange format, or very large? You may need to resize it slightly if it's huge. You can also send it to me via email if needed :teeth:
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
78buckshot
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Location: Stockbridge/Chelsea, Michigan

Thu Dec 20, 2018 5:13 pm

Is your generator fueled by natural gas or diesel? How old is the unit?
Chris
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Thu Dec 20, 2018 7:21 pm

A friend of mine sent me some info on this when I sent him your question. This was his response:

"You have a picture of the engine ? The efc actuator it self is located in the PT pump. That actuator is driven by a governor driver. If he follows the wires back from the actuator he will be able to locate the driver. If everything is working as it should all he will have to do is turn a rated speed pot clock wise."

"A easy way to check for proper rpm with a fluke meter is just to put the leads across any phase and set to frequency.

RPM & frequency are directly proportional.

60.00HZ will always equal 1800RPM with a 4 pole rotor & 3600 for a 2 pole

On the older units I like to set the frequency a bit higher that way it falls to 60.00 dead on when the unit is loaded.

The later ones seem to hold on it regardless of load."

The frequency to Hz part is for any generator, and is a very accurate way to determine engine speed.

Hope this helps!
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
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