MEP 806A Frequency gradually climbing on its own

[Austin2406]

Does anybody happen to know why thr frequency would start climbing on its own on the 806A?

 

[Guyfang]

How far? How fast?

 

[Austin2406]

Gradually climbes to about 450hz to 460 hzat about 1 hz per second immediately after start up. We've checked MPU & GCU. Both are working correctly

 

[Guyfang]

Is this set new to you? Have you ever seen it work right?

 

[Austin2406]

No, not new to me. It was working fine then just started overspeeding.

 

[Ray70]

I'm assuming this is an MEP-816A, not an 806A as stated in the title.... Since an 806 would spill it's internals long before 12,000 RPM!

 

[Austin2406]

I'm assuming this is an MEP-816A, not an 806A as stated in the title.... Since an 806 would spill it's internals long before 12,000 RPM!

No, it's a 806A.

 

[Guyfang]

I'm assuming this is an MEP-816A, not an 806A as stated in the title.... Since an 806 would spill it's internals long before 12,000 RPM!

Ray,

Don't work that way. Same engine, as the 816A. But the main gen has more winding/fields.

 

[Guyfang]

How long have you had the set? Or better said, how long did it work right?

Have you done any work on it? Changed any parts? Removed or replaced anything? Engine or control cube?

How did you check the GCU? IAW the TM?

 

[Ray70]

Well, the 12,000 rpm thing was a joke, but you guys lost me somehow.... This is an 806a running at 450Hz? what am I missing?
Thought the 806a was a 60Hz machine and the 816a designation was 400Hz.? This is an 806a running at 400+Hz?
Have the earth's magnetic poles flipped?? What gives? Please explain where I went off the rails... Cause checking the TM didn't help me.

 

[Guyfang]

Did not realize you were kidding, as I have had people tell me that same thing.

That's what I am trying to find out. How that can happen. Normally can not happen. Need to know if any work was done on it of late. Need to know if any parts have been changed of late. How long it ran right. That way we can eliminate some things from the get go.

 

[kloppk]

OP might have been measuring the AC frequency out of the MPU to see the RPM drift up.

 

[Ray70]

Either that or he's using a cheap DMM? I once saw 400+ Hz on a cheap Chinese gen but it was due to dirty power and using a DMM.
I thought the OP meant he was reading it off the Hz gage, which blew my mind on an 806!
What are you actually seeing on the HZ gage?

 

[jmenende]

If the engine actually slowly incerasing rpm then i would check the ip and the governor linkage. Could be stuck or just set wrong.

 

[Guyfang]

Everyone needs to stop and take a deep breath here. Read and look at the TM's.

1. A MEP-806A can NOT read 400 hertz on the meter. Can not The meter only goes a little higher then 70 hertz?
2. A MEP-806A can NOT read 400 hertz on the meter. Because the Freq. Transducer can not read 400 hertz.

So where are the readings coming from? The 120 volt outlet? The load terminals?

I have to run now. So will be back later. How about some answers? And I HAVE seen a 806A produce 400 hertz!