Frequency meter erratic

[technoid]

My MEP 803a has an erratic. Frequency meter. My Fluke meter reads steady freq. So what is causing the analog meter on the panel to be erratic?

 

[Light in the Dark]

Have you checked the connections from the gauge, back through the machine to their source? A loose connection can cause intermittent readings. If your meter reads fine, and you don't hear the machine varying its RPM... we look at connections, or the gauge itself. Have you deoxidized the switches and connections in the machine? Oxidation can cause intermittent readings more often than loose connections.

 

[technoid]

They are all tight. What switch controls the meter? I assume its direct wired to its pickup.

 

[kloppk]

The Frequency Transducer A7 gets it's input from S8 the reconnection switch inside the control cube. It picks up L3 & L0 from there.

 

[kloppk]

Looks like the Freq Meter is a 200 micro amp AC current meter. So at 60 hz it looks like the current from transducer should be 100 microamps.

The -24 TM has test procedures for the transducer and the meter.

 

[technoid]

Thank you! I will go through the test proceedure. Love

 

[csheath]

My frequency gauge didn't read at all and my power and voltage gauge were inaccurate. I made some adapter plates and converted to digital meters.

The square combination meter for total voltage and Hz reads 5 volts low but the Hz matches exactly with my Fluke. All I had to do on it was attach the leads from the old voltage gauge to the new combination meter.

The volt amp meters I put on L1 and L3 seem to be accurate for both volts and current. The whole thing can be done for under $30 and some time and wiring.

 

[technoid]

My other analog meters are close in reading compared to the fluke. Its just the freq meter that is crazy.

 

[Ray70]

They also make a blue digital Hz gage in the same small package size as your V / Current meters. I just bought some for about $7 each. You can also get cheap round analog 90mm gages on ebay from a place in china. Direct read Hz for $12 and 300V AC for about $6. They are pretty chincy plastic, but they work and fit right into the original holes.

 

[technoid]

Thank you, I will put that in my notes for future reference.

 

[Guyfang]

My MEP 803a has an erratic. Frequency meter. My Fluke meter reads steady freq. So what is causing the analog meter on the panel to be erratic?

Please define "erratic". Movement full scale left then right and so on? Two three hertz back and forth? High or low amplitude? Regular as clock work? It helps to know. Is the engine surging any, in time to the motions?

 

[frank8003]

I burnt up an antique milliamp meter today,
45 years old.
let the smoke out of it

 

[technoid]

It bounces from 60 to 80 and sometimes down to zero. Its not a steady fluctuation. Sometimes it stays at 60 for about 5 seconds.

 

[technoid]

Engine runs steady. My fluke shows very little change in freq.

 

[Guyfang]

It bounces from 60 to 80 and sometimes down to zero. Its not a steady fluctuation. Sometimes it stays at 60 for about 5 seconds.

I would take the meter apart. That kind of thing sounds like a tiny wire is loose or broken off in the meter. AND YES, you can take them apart and fix them. Not often, I admit. But every once in a while.