Mep 806B Frequency Drop

[Mitchell45]

We have a Mep806B model generator. She runs great but when connected to a load bank and applying a load the frequency drops from 400 to 390-392 and does not recover until the load is removed. Any ideas what it could be?

 

[MrShawn305]

Two things:

First, is it an 806 or 816? I thought the 806 is a 60hz model and 816 is the 400hz

Second, on the control panel, there should be a frequency adjust switch. Does the frequency increase if you hold the switch in the up position?

 

[Guyfang]

Indeed. What do you have?

MEP-806B is a 60 hertz gen set.
MEP-816B is a 400 hertz set.

Have you ever seen it run properly? Is the set new to you?
How much of a load are you asking the gen set to accept?
Have you downloaded the TM's, and perhaps read them a bit?

 

[Mitchell45]

Sorry I’m so used to working with 60hz I mistakenly said 806 but it is indeed an 816B 400hz

To answer your questions, when you push the frequency adjust switch the frequency would not go up, no the generator is not new to me and it has run well in the past.
To answer your questions, when you push the frequency adjust switch the frequency would not go up, no the generator is not new to me and it has run well in the past, and yes I have the TO’s

We were able to correct the issue, just had to adjust the set screw providing fuel to the actuator. But now unfortunately the other issue we are seeing is we have the same generator paralleled to another and they are running great and sharing fine until we put about 45kw between the two and then the power reading shoots through the roof and throws the generator system overload/ generator output power abnormally high fault on. Not sure if anyone has seen that before?

 

[Guyfang]

Never seen a fault like that.

Are you running a PP, Power Plant setup? Or two PU's?

 

[Mitchell45]

Running them as a power plant setup on a trailer.

 

[Guyfang]

With the Distribution box and assorted cables? Like a AN/MJQ-41B? Or are both mounted on one trailer? Reason being, the D-box and paralleling relay in it can cause problems. And often, when it is two sets, (as PU's instead of PP's) and only a paralleling cable and a buss bar, the connections, if not tight, can generate heat and give the gen sets the indication of a overload.

400 hertz. What kind of load? Plain Restive, like a load bank? Or an active load, equipment that has sup loads that can turn on and off at will?

Since you are in Utah, are you at Tooele? Or active duty? Thats all I worked on for 20 years, 400 hertz, Hawk and Patriot.