My "new" MEP-002A will not display Hz

[1800 Diesel]

Your Frequency transducer is probably shot. (upper left corner of your 4th pic.) an easy way to test it is to detach the 2 AC in wires on the left side of the transducer and attach a line cord in their place. Plug it into utility power and see if it reads 59-60 hz. If you still get nothing then most likely the transducer is dead. If by some slim chance you do get a good reading, then you will need to look at the rest of the system, probably starting with the transformer feeding the transducer.

Rather than start a new thread I'll use this one since it's basically the same issue for me with an MEP-002A. At governed speed the generator is producing proper voltage and frequency (verified by a known good external meter). The problem is that the unit's freq meter generally pegs to the right. I checked voltage on the AC input side & read about 1.8V, obviously not 120V. I also removed the two AC connections and connected grid power and the freq meter pegs to the right. On the surface that seems to indicate a bad transducer but then why does it show the same results with only 1.8volts AC coming in? Another question, does the low voltage indicate bad transformer(s)? So far I haven't had to service one of those, but they do appear to be a PIA to remove and replace...

Edit 1: Found TM-12 instructions for resistance testing T1 & T2 primary and secondary windings. Planning to get that done tonight or in the morning and will report findings.

Edit 2: Before I started removing wires connected to T1 transformer I found that the J9 amphenol connector was loose with only one or two threads engaged. I backed out the connector and cleaned up the pins & sleeves a little and reconnected. Now I have 120 volts at the AC input of transducer A3. Started up unit but still no good frequency reading. Tried a different freq meter and same results. Tried adjusting the transducer settings but no success. Also connected grid power to A3 & freq meter pegs to the left side. Verified wire numbers were correct at each connection on both AC & DC sides of A3. So now I've pretty much decided the A3 transducer is beyond salvage so I need to come up with a replacement.

Edit 3: Maybe it was a bad idea connecting my issue to this thread. Moderator--was this not the correct thing to do?

To update (and now I'm really lost):

Installed a known-good freq meter and transducer from an MEP-003A I have in the shop and then started up the MEP-002A and set it to 60hz using my external meter. The on-board meter is pegged past 65hz, same as the original meter/transducer.

I checked AC voltage into the transducer #2 terminal and got 120v (I connected my voltmeter black to L0 & red to #2.) I also checked TB5-13 across to L0 and got 120v. Got no voltage from L0 to TB-12.

Now for the really confusing part: I then disconnected the generator AC input wires and connected line voltage to the transducer at #1 & #2 and the frequency meter pegs to the right at 65hz +, just like when the unit is running. Does anyone have any ideas what's happening??

 

[1800 Diesel]

I guess everyone's stumped just like me.... this evening I checked voltages on a few terminals on a known-good MEP-003A unit that I've had for many years.

#2 AC input to transducer reads 120v & #1 AC input reads none or residual voltage. These values are from L0 to each terminal separately. (Of course they also read 120v across each other.)

I then checked TB5-13 to L0 and got 120V and residual from L0 to TB5-12. These readings are identical to the ones I'm getting on the problem set. The only thing I haven't done is installed a third transducer & freq meter, which I'll try to do tomorrow.

If anyone has any brainstorms please let me know. I'm feeling like the lone ranger out here....

 

[Chainbreaker]

If anyone has any brainstorms please let me know. I'm feeling like the lone ranger out here....

So, if you were to transplant the -002's transducer & meter into your -003 would that tell you something? Seems like you have done everything else but that. However, that should be the same as running the transducer and meter on grid power (known good voltage & Hz). Pretty strange situation, but there is a problem somewhere... I'm wondering if it could be something quirky like a bad ground strap connection (intermittent) to Control Cabinet?

 

[Guyfang]

This is the first time I have seen this thread.

Is is this a new set to you? Have you ever seen it run right? If you have never seen it run right, the troubleshooting chain is longer.

First off, if it's new to you, LOOK at both the transducer and meter, and make sure they are 60 hertz. The same with your "known", ( how do you know that they are good?) good transducer and meter. Don't scoff, I have seen it happen many times before. If it isn't written on the components 60 hertz, then look up the part numbers in the TM. As a minimum, the part numbers will be on the components.

Normally I would say it's the transducer. As Chainbreaker mentioned, better to install known bad parts in a known good set. One at a time. Putting "known" good parts in a set that dosnt work, brings you nothing. What does the TM say, in the testing of the transducer? 120 in, and what do you get out? I am using a tablet, as my GD computer is non-op. If the transducer passes the test, it's good. You have a problem someplace else. Start with the transducer test. There is no if,ands or buts. It works, (right output) or it doesn't. If you still have doubts, then put the components in the working gen set, one at a time. Meter first.

The TM calls for a matched set, when replacing either part. I tend to disagree. The reason they are a matched set, is because at the factory, some old and wizened person hooked them up to 120 volts, and then adjusted both the transducer and meter to read perfictly together. You can do that yourself, if you just need to be perfictly 100%, right on the money.

 

[1800 Diesel]

So, if you were to transplant the -002's transducer & meter into your -003 would that tell you something? Seems like you have done everything else but that. However, that should be the same as running the transducer and meter on grid power (known good voltage & Hz). Pretty strange situation, but there is a problem somewhere... I'm wondering if it could be something quirky like a bad ground strap connection (intermittent) to Control Cabinet?

Morning Chainbreaker--On the reverse swap-out of meter & transducer, that's not a bad idea. I'll give that a try today.

Also, thought about the cabinet grounding issue the other day but all I did was to connect a small alligator-clipped ground wire from the main ground lug (for earth ground) to the control cubicle cabinet. Today I'll actually remove all grounds on the unit, clean contact surfaces and reinstall with new fasteners. I did notice the small hex bolts & washers for all the ground straps are rusted. I didn't actually do anything with any ground connections on the AC Output Control Box but will add that to my list. I would think a missing or bad ground connection would affect other gauges/meters, but with these sets, I guess one never knows what gremlins exist.

I'll rework all the grounds sometime today and also install the original meter/transducer pair in my 10K unit and post any results good or bad.... Also, appreciate your assistance!

 

[Guyfang]

Morning Chainbreaker--On the reverse swap-out of meter & transducer, that's not a bad idea. I'll give that a try today.

Also, thought about the cabinet grounding issue the other day but all I did was to connect a small alligator-clipped ground wire from the main ground lug (for earth ground) to the control cubicle cabinet. Today I'll actually remove all grounds on the unit, clean contact surfaces and reinstall with new fasteners. I did notice the small hex bolts & washers for all the ground straps are rusted. I didn't actually do anything with any ground connections on the AC Output Control Box but will add that to my list. I would think a missing or bad ground connection would affect other gauges/meters, but with these sets, I guess one never knows what gremlins exist.

I'll rework all the grounds sometime today and also install the original meter/transducer pair in my 10K unit and post any results good or bad.... Also, appreciate your assistance!

If you think the ground is a problem, disconnect the meter ground wire and use an ohm meter from the wire end, to panel ground.

 

[1800 Diesel]

This is the first time I have seen this thread.

Normally I would say it's the transducer. As Chainbreaker mentioned, better to install known bad parts in a known good set. One at a time. Putting "known" good parts in a set that dosnt work, brings you nothing. What does the TM say, in the testing of the transducer? 120 in, and what do you get out? I am using a tablet, as my GD computer is non-op. If the transducer passes the test, it's good. You have a problem someplace else. Start with the transducer test. There is no if,ands or buts. It works, (right output) or it doesn't. If you still have doubts, then put the components in the working gen set, one at a time. Meter first.

Guyfang, Strangely enough, TM 24 (Depot Maintenance) doesn't actually have much detail for testing the transducer other than connecting a known good freq meter to the set and verifying 60hz. I've looked though all the TMs for the 002A & 003A units but haven't located any further details for testing. The DC voltage out is so low it's next to impossible to test. I think I'll go back to original parts and then swap out meter first with original transducer installed and then do the reverse. Thanks for weighing in!

Wishing you and the good people on this forum a great Thanksgiving week!

 

[1800 Diesel]

If you think the ground is a problem, disconnect the meter ground wire and use an ohm meter from the wire end, to panel ground.

Guyfang--I checked the negative meter wire (#D74A16) & it appears to be a "floating ground" with no continuity to any frame grounds. Checked the same on my [working properly] MEP-003A & it shows the same condition (that the negative side of the transducer and the negative side of the meter (same wire #D74A16) is not common to ground.

Edit--I missed your question about the generator being "new to me". The answer is yes. I did the standard fuel system maintenance and oil & filter change and then ran the unit to test its viability. Everything else is working properly (except a sticky linkage on the throttle control).

I've seen threads on the other generator forum where folks advised to reverse the leads on the freq meter when the pegged needle condition is found. However, since that advice doesn't follow the wiring schematic (and expecting damage to the meter) I'm reluctant to go down that path. As everyone knows, these meters aren't sitting on a shelf at the dollar store...

 

[Guyfang]

I took this out of the MEP-006A book. Same, same.

3-9. Frequency Meter and Transducer Test.To test the frequency meter and transducer of the controlcubicle, proceed as follows:

CAUTIONThe frequency meter and transducer are amatched set and must be tested as a set.
a—. Connect a variable frequency 120 Vac sinusoidal inputto the ac side of the frequency transducer,b. Connect a master frequency meter across the input.The master frequency meter shall have inaccuracy of aminimum of 3/4% or greater of the set frequency meter andtransducer (l/20 of l percent).c. Vary the frequency from lowest scale reading to fullscale reading.d. The error at any point in frequency meter shall not begreater than l percent.e. If the above requirements are not satisfied, replaceboth the frequency meter and transducer.

Not really a satisfying answer. I seem to remember seeing someplace, a test procedure that game me concrete figures to measure.

 

[1800 Diesel]

I took this out of the MEP-006A book. Same, same.

3-9. Frequency Meter and Transducer Test.To test the frequency meter and transducer of the controlcubicle, proceed as follows:

CAUTIONThe frequency meter and transducer are amatched set and must be tested as a set.
a—. Connect a variable frequency 120 Vac sinusoidal inputto the ac side of the frequency transducer,b. Connect a master frequency meter across the input.The master frequency meter shall have inaccuracy of aminimum of 3/4% or greater of the set frequency meter andtransducer (l/20 of l percent).c. Vary the frequency from lowest scale reading to fullscale reading.d. The error at any point in frequency meter shall not begreater than l percent.e. If the above requirements are not satisfied, replaceboth the frequency meter and transducer.
Not really a satisfying answer. I seem to remember seeing someplace, a test procedure that game me concrete figures to measure.

Unfortunately I don't possess any of the required test equipment (with the exception of an EXTECH meter that does read frequency) and I have no way to vary frequency unless I change engine speed or make adjustments on the back of the transducer--which so far has not made any difference to the needle position on the meter. And I always leave the throttle control on these units to start up at near 1800 RPM and make fine adjustments after the engine warms up.

I'll get back on the task later this afternoon and let you know if anything new comes up. Thanks for checking in!

 

[1800 Diesel]

So, if you were to transplant the -002's transducer & meter into your -003 would that tell you something? Seems like you have done everything else but that. However, that should be the same as running the transducer and meter on grid power (known good voltage & Hz). Pretty strange situation, but there is a problem somewhere... I'm wondering if it could be something quirky like a bad ground strap connection (intermittent) to Control Cabinet?

Installed the original MEP-002A freq meter/transducer set into another MEP-003A I'm working on and the meter worked correctly, although since I had fiddled with the adjustment screws on the back of the transducer, the meter reading is low by ~2 hz so I'll need to adjust it tomorrow.

Didn't have time today to remove and clean any grounds. Hope to get to that tomorrow. Rapidly reaching the point of installing an aftermarket freq meter powered by AC voltage and end this rat killin'....

 

[Guyfang]

You have changed out both the transducer and the meter. and also put them in another set and they worked correctly. You have applied line voltage to the A3 and it still dosnt work. About the only thing I would try now, is to take two wires and run the from the output side of A3 to the meter. If it works, then it can only be the wiring between the A3 and meter. By any chance, is there a coil, or spring between the meter terminals? If so, remove it. Someone else had the same problem. The coil is for shipping purposes only.

 

[1800 Diesel]

You have changed out both the transducer and the meter. and also put them in another set and they worked correctly. You have applied line voltage to the A3 and it still dosnt work. About the only thing I would try now, is to take two wires and run the from the output side of A3 to the meter. If it works, then it can only be the wiring between the A3 and meter. By any chance, is there a coil, or spring between the meter terminals? If so, remove it. Someone else had the same problem. The coil is for shipping purposes only.

Yesterday I connected my VOM between the DC output terminals of the transducer and the terminals at the M3 meter and found 100% continuity on both wires (- lead D74A16 & + lead D75A16).

I did not check the AC side but did confirm I'm getting 120v on the #2 terminal--this one apparently is the "hot" one and the #1 is the neutral since it reads near zero voltage. At first I thought the #1 reading was an anomaly but I found the same "residual voltage" on #1 terminal on both working MEP-003A units.

If I'm getting 120v at #1 on A3, is there any reason I should check T1 or T2 transformers? So far I have not done that. With main circuit breaker closed I'm getting a clean 120v at L1 & L3 (with no loads), but did connect a small heater (750 watt) to the convenience outlet for about a minute with no issues.

No coil between the terminals on M3.

Later this evening I still plan to remove all ground straps, clean contact areas & reinstall with cres fasteners and a little anti-seize.

 

[Guyfang]

Both T1 and T2, get their input from the A2. Both T1 and T2 directly feed the A3. The only way that's possible, is to insure that they are the same phase, or they would make a short. Or am I wrong? Would going through the transformers keep that from happening? I am not a Double E. Are any of our EE's keeping an eye on this thread? How about a hint here.

If both components have been installed in another gen set, and worked, then the components have no influence on the problem. If the wires from the A3 to the M3 have been tested and are good, the wire harness has no influence on the problem. If the 120 volt AC input to the A3 has been tested and is good, (comes from the A2) What else do we have? The A2, and the T1 and T2.

On your A2, are there jumpers between 1,2 3 and between 4,5 and between 8,9? Have you looked at the wires hooked up to the A2?

Yesterday I connected my VOM between the DC output terminals of the transducer and the terminals at the M3 meter and found 100% continuity on both wires (- lead D74A16 & + lead D75A16).

Did you disconnect both end of the wires before testing the wires?

 

[1800 Diesel]

Did you disconnect both end of the wires before testing the wires?[/COLOR]

OK, we're dogging things off here in FL for Thanksgiving preps with family. I'll regroup with my MEP work sometime on Saturday. Still have some loose ends to troubleshoot.

To answer your question about the DC wires to the meter from A3, no I did not disconnect them, but will recheck on Saturday with them as "stand-alone" and disconnected at both ends. Good point...

Again, a big FL panhandle Happy Thanksgiving to all!

 

[Guyfang]

I also measure from the wire to ground. Never know, could be worn through someplace. Or, could the tires to the meter have contact with another source of voltage, perhaps from another wire in the harnes?

Well, have a happy and pleasant Thanksgiving Day to you and everyone who reads this Forum. We here in Germany have to push off the turkey and stuffing until the weekend. Sadly, we have not yet convinced the Germans to celebrate with us yet. I suppose we could drive to the Grafenwoir Post, and join the the Soldiers today. Might just have to think about that one!

 

[Chainbreaker]

And today in the U.S. its happy leftovers day (the day after the annual T-Day gorging). Burp...!

 

[Guyfang]

The bird is thawing for Saturdays festivities. Better to be a few days late, then not at all.

 

[1800 Diesel]

And today in the U.S. its happy leftovers day (the day after the annual T-Day gorging). Burp...!

Amen to that! Had a New Orleans T-day with family. 2 smoked turkeys, 1 smoked ham, oyster dressing, mirliton dressing, a bunch of other sides and I lost track of how many pecan and apple pies were there for the choosing! As my father used to say (many years ago) during these amazing meals & times with family--"I wonder what the rich people are eating today?" God bless America!

 

[Guyfang]

My Father said the same exact thing. It doesn't translate well, here in germany. Whenever I say it, people look at me like I have a third eye in the middle of my forehead. Still make good sense to me!!