MEP005A frequency meter not working.

[yohanusmarcus]

Just bought a 1971 mep005a today. Seller said it wasn't charging so I wasn't clear on what he meant. He started it before we loaded it up an it did not produce power. When I got home with it, I started it holding the start switch approximately 5 seconds and it started producing power at 120v, but the frequency meter doesn't appear to work. I don't have a manual for it and need advice. Should I just buy a new meter as I have read that it's common for the transducer to go bad on these. Thanks in advance

 

[Ray70]

Hello,
The manuals are all available right here at the top of the page in the TM section, then Generators then find the Mep-005 folder.
99% of the time that problem is caused by a faulty frequency transducer mounted inside the control panel.
That particular transducer is pretty much obsolete, but there are usually newer versions available that will work, they just have slightly different mounting hole locations.

 

[Ray70]

Here's a handful of options, if yours ends up testing bad.
The gage/ transducer combo's are a bit pricey.
The newer transducer will work in an 802/803, 002/003 and I believe will also work in an 004,005 and 006.

300-12, TRC Instruments Frequency Meter With 69595 Transducer | eBay

Removed from military generator. NSN 6625000030971. Mfg Number: 300-12, 69595. Manufacturer: TRC. NSN: 6625-00-003-0971.

www.ebay.com

NEW TRC FREQUENCY METER AND FREQUENCY TRANSDUCER PART # 69-595 MATCHED SET | eBay

Diaflange, 2.800 in. Depth behind mtg flange, 3 mtg holes0.150 in. Radius, freq transducer 50/60hz, ac input, dc output. FREQUENCY TRANSDUCER MATCHED SET. PART # 69-595.

www.ebay.com

FREQUENCY TRANSDUCER | eBay

FREQUENCY TRANSDUCER 50/60 HZ, P/N 19280 MILITARY GENERATOR.

www.ebay.com

TRC Frequency Transducer Control Converter 60 HZ p/n 13211E6901 10380 New qty. | eBay

Pr9shelfA for inventory .

www.ebay.com

 

[Light in the Dark]

Alternate source for the last one Ray called out. https://www.easternsurplus.net/Part...ertz-Control-Converter-MEP-Electric-Generator

 

[yohanusmarcus]

Started the machine this morning and it's running great. Voltage meter reads 240 volts, power meter reads at 25%, rated current meter is approximately 30% and the frequency meter needle bounces from 48 to just under 48 1/2. I tested the transducer with digital volt meter had 120 volts ac in and 2 volts DC out. Also checked the convenience receptacle and no voltage there at all, of course that could be a bad plug as on side is cracked.
My wife also read something about adjusting the governor, but I don't know where it might be or if it has one. Any further ideas or tests I should make?

 

[Ray70]

When you start the machine are you holding the switch up for several seconds after it starts? If not that can affect the Hz meter function.
2nd, if you have a kill-a-watt meter or frequency setting on your DMM, what is the frequency that it reads?
If its not around 61.5, adjust your throttle until it is.
Lastly, the output of the transducer is not a DC voltage signal that you are looking for, it's DCmA
Having DC voltage is a good sign, but that's not exactly what is driving the gage.
First make sure you are starting it correctly, then make sure the engine speed is correct.
If those both check out , the transducer is last to check out.

 

[Light in the Dark]

As Ray said, you need to nail down what RPM you are currently running at (as its directly proportional to hertz). Kill A Watts are a great cheap tool for your arsenal.. so is a digital multimeter with the more extended features. If you find you are at or near the right RPM, it is easily adjustable to correct then as Ray says, you can diagnose the last bits of the puzzle. I wouldn't worry about the governor just yet.

 

[2Pbfeet]

FWIW: I use a small panel mount digital frequency meter that I wired to a short extension cord, and put a heat shrink cover on the terminals to keep an eye on my generators. It is bright, easy to read, and portable. If I'm not at the generator when it is in use, I plug it in near me in the house, just to keep an eye on things. I keep meaning to put it in its own project box, but that is not making it to the top of project lists and the moment.
Something like this;

Amazon.com

All the best,

2Pbfeet

 

[yohanusmarcus]

When you start the machine are you holding the switch up for several seconds after it starts? If not that can affect the Hz meter function.
2nd, if you have a kill-a-watt meter or frequency setting on your DMM, what is the frequency that it reads?
If its not around 61.5, adjust your throttle until it is.
Lastly, the output of the transducer is not a DC voltage signal that you are looking for, it's DCmA
Having DC voltage is a good sign, but that's not exactly what is driving the gage.
First make sure you are starting it correctly, then make sure the engine speed is correct.
If those both check out , the transducer is last to check out.

Yes I've held the start switch for at least a minute.

 

[yohanusmarcus]

When you start the machine are you holding the switch up for several seconds after it starts? If not that can affect the Hz meter function.
2nd, if you have a kill-a-watt meter or frequency setting on your DMM, what is the frequency that it reads?
If its not around 61.5, adjust your throttle until it is.
Lastly, the output of the transducer is not a DC voltage signal that you are looking for, it's DCmA
Having DC voltage is a good sign, but that's not exactly what is driving the gage.
First make sure you are starting it correctly, then make sure the engine speed is correct.
If those both check out , the transducer is last to check out.

I see now on the transducer 0 to .5 mv if I read that right my eyesight ain't what it used to be. I'll probably have to get the unit off my trailer as I have two of them side by side and can't access both sides of the machine.

 

[yohanusmarcus]

Also is it supposed to run with the battle short switch on?

 

[Ray70]

the face of the gage reads FS=500 UADC so .5 milliamps DC should give you 62hz on the gage.
Milliamps, not millivolts.

 

[yohanusmarcus]

the face of the gage reads FS=500 UADC so .5 milliamps DC should give you 62hz on the gage.
Milliamps, not millivolts.

Thanks Ray I just couldn't see it's that small print

 

[Ray70]

No problem... I used your picture up above and zoomed in on it.
My eyesight up close is dwindling down over the last couple years too!
Need a flashlight and glasses to see the menu at restaurants now!

 

[Light in the Dark]

My wife's fighting with me to get reading glasses for the small stuff. I told her I didn't see the need.

She wasn't as amused as I was.

 

[Guyfang]

You wrote:
Yes I've held the start switch for at least a minute.

This is not a good idea. If you hold it up 10-12 seconds, and the voltage has not come up, its not coming up. But if you continue to hold it up, you are liable to damage the exciter function.

Use a meter to find out what your hertz is. Use the 120 volt outlet. If you have no output at the plug, cycle the CB, (Circuit Breaker CB3) next to the plug. If it still has no output, Check for AC voltage at the two hot wires that hook to the plug. Make sure you have the right hertz. If you are running the engine too slow, bad things can happen. Once its putting out 120 volt, the hertz should be right. BUT don't guess. Once you have set the throttle control knob for the right hertz, LEAVE IT THERE. You do not idle these machines. Simple turn the set off, and leave the know where its at.

You wrote:
Also is it supposed to run with the battle short switch on?

The word Emergency, or battle short mean it CAN run with S17, (Battle short switch) up, but if you need to use the S17, you have a problem. One of the idiot lights should be on, while running if the S17 is in the up position. What light is on?

 

[yohanusmarcus]

You wrote:
Yes I've held the start switch for at least a minute.

This is not a good idea. If you hold it up 10-12 seconds, and the voltage has not come up, its not coming up. But if you continue to hold it up, you are liable to damage the exciter function.

Use a meter to find out what your hertz is. Use the 120 volt outlet. If you have no output at the plug, cycle the CB, (Circuit Breaker CB3) next to the plug. If it still has no output, Check for AC voltage at the two hot wires that hook to the plug. Make sure you have the right hertz. If you are running the engine too slow, bad things can happen. Once its putting out 120 volt, the hertz should be right. BUT don't guess. Once you have set the throttle control knob for the right hertz, LEAVE IT THERE. You do not idle these machines. Simple turn the set off, and leave the know where its at.

You wrote:
Also is it supposed to run with the battle short switch on?

The word Emergency, or battle short mean it CAN run with S17, (Battle short switch) up, but if you need to use the S17, you have a problem. One of the idiot lights should be on, while running if the S17 is in the up position. What light is on?

None of the lights are on with s17 on. They all light when I toggle the reset test switch, so all the bulbs are good. I'll have to remove the 120 receptacle to check directly on the wires. I don't idle the machine, if anything I'm running more than 60 HZ. Currently I don't have a kill-a-watt meter or a dvm that will read frequency, I'll have to get one or both soon. I do understand basic electrical nomenclature. (Frequency is related to rpm of the engine. This machine produces both single phase 120/208, or 3 phase 240/480 etc.) I'm just not familiar with this machine per say. Eaven though I believe it's the same unit we used at Ft. Knox in the late 80s.

 

[yohanusmarcus]

None of the lights are on with s17 on. They all light when I toggle the reset test switch, so all the bulbs are good. I'll have to remove the 120 receptacle to check directly on the wires. I don't idle the machine, if anything I'm running more than 60 HZ. Currently I don't have a kill-a-watt meter or a dvm that will read frequency, I'll have to get one or both soon. I do understand basic electrical nomenclature. (Frequency is related to rpm of the engine. This machine produces both single phase 120/208, or 3 phase 240/480 etc.) I'm just not familiar with this machine per say. Eaven though I believe it's the same unit we used at Ft. Knox in the late 80s.

I just started the machine to check for lights on the only light that is on is the battle short light

 

[Guyfang]

Will it run without S17 on?

 

[yohanusmarcus]

I just started the machine to check for lights on the only light that is on is the battle short light

Will it run without S17 on?

No