MEP004A Frequency Problem

[Motownmike]

HI everyone. I just purchased this set, and thanks to Sewerzuk's videos, I was able to get it running in no time at all.
I do have a question/issue. After the start and flashing of the field, I get voltage output on the gage, but the frequency meter starts to rise on start then when it reaches operating rpm it drops back to zero, as if it's tripping something off.
The service receptacles are working fine and like I wrote above the voltage meter works correctly. I don't notice any change in my drop light that's hooked to the service plugs.
I'm guessing that since the set is putting out power ( I didn't check the L1-L3 terminals yet) that it's a sensing issue.
Any suggestions?
Thanks, Mike

 

[Ken_86gt]

The frequency gauge is powered by a transducer that is mounted in the panel behind the meter. The system has a reputation for not being very reliable. My guess is that the transducer has failed. But- check for voltage on it while running, ~120V on the input side, and check the wire connections on the transducer and meter.

Many of the transducers are matched to the meter and should be replaced together..... You can buy a digital frequency meter that operates directly off of the 120V input if you want a much cheaper replacement option. It is made by Hardy Diesel and costs about $20. These can be found on your favorite auction site or hardydiesel.com.

 

[Motownmike]

Thank You

I'll meter that out when I get home from work today. I think the gage is functioning because it does register, it just falls off as the rpm reachs steady-state. The transducer sounds like the culprit.
Mike

 

[PeterD]

T... The system has a reputation for not being very reliable. ....

Ken has a flair for understatement! There are other alternatives, both long term (replacement) and for short term. Some digital VOMs have frequency (Saw one in Harbor Fright the other day, in fact) and the Kill-A-Watt device also will read frequency.

My MEP-004's frequency meter transducer has two adjustments on the bottom (only accessible when removed!) and I think that moisture manages to get into them causing issues there. In my case I exercised the adjustments with a screwdriver (after marking the original positions) and things settled down a lot. Then I used the AC shop power to fine tune the adjustments so that 60 Hz was exactly (well, as close as one can get on that meter!) to 60 as possible. I did not bother with the 50 Hz calibration, I'm never going to run at 50 anyway. Total time was well under an hour, most removing the transducer and the meter and hooking 'em together on the bench to test (using a suicide cord, of course). The transducer's input is 120 volts which helps greatly in testing.

Just work carefully, and you should be OK, but if that is not the solution and you don't really care about keeping it original, there are a lot of replacement options too.

 

[1942 Mk1]

I have an MEP004 that I have finally got to run, but have no power output. Where can I access the procedure to flash the field? And while I'm about it, what do I use for search words to find Sewerzuk's video?

Thanks,
Carroll

 

[PeterD]

I have an MEP004 that I have finally got to run, but have no power output. Where can I access the procedure to flash the field? And while I'm about it, what do I use for search words to find Sewerzuk's video?

Thanks,
Carroll

Assuming that the generator set works...

either:

1. When starting continue hold the start switch up until the volt meter and/or frequency meter read close to working voltage/frequency. There is a special interlock that prevents problems with the starter running so this is safe (and the recommended way to do it.)

or

2. Once running, should you forget to do as in #1 above, simply press the start switch up to the start position for a few seconds. The field will then flash. Again, that interlock will prevent the starter from engaging.

Which video? There is one in this tread: http://www.steelsoldiers.com/auxill...ifferent-voltages-including-single-phase.html but I'm not sure it is the one you refer to. Search for all posts by a username and then the titles should give you a clue. Also, IIRC Iggy posted a run video as well which he did with his son?

 

[sewerzuk]

HI everyone. I just purchased this set, and thanks to Sewerzuk's videos, I was able to get it running in no time at all.
I do have a question/issue. After the start and flashing of the field, I get voltage output on the gage, but the frequency meter starts to rise on start then when it reaches operating rpm it drops back to zero, as if it's tripping something off.
The service receptacles are working fine and like I wrote above the voltage meter works correctly. I don't notice any change in my drop light that's hooked to the service plugs.
I'm guessing that since the set is putting out power ( I didn't check the L1-L3 terminals yet) that it's a sensing issue.
Any suggestions?
Thanks, Mike

Glad I was able to help!

Normal behavior for the frequency meter is for it to rise partially as the engine is picking up RPM and quickly peg low, and then slowly come up to the actual frequency. Every set I have worked on does this. So, you MIGHT simply have the set adjusted to too low of an RPM, and the gauge is pegged low because frequency is too low.

As others have discussed, the frequency transducer in these sets is unreliable. I have had to replace several of them.

Maybe I missed it, but I haven't seen anybody recommend checking actual frequency with a standalone frequency meter. I do this on every set that I work on...probably close to 1/2 the time I find that the set's meter is off, sometimes by a lot. I worked on one that was indicating 60hz but was running at 48hz. Even if you do get your meter to work, I wouldn't trust it until you have verified it with another meter. Edit: some electronic equipment, particularly transformers and digital equipment, are extremely sensitive to frequency. 1 or 2 hz probably won't damage anything, but the 12hz in my example almost certainly would.

Some of the transducers are adjustable, some are not. The ones that are not are calibrated to a specific frequency meter (you need a matched set, as ken_86gt explained).
If you do try to adjust yours, you'll find that the 2 adjustment pots are locked into place with a small dot of epoxy; you'll need a small razor blade to carefully carve the epoxy out of the slot.

 

[sewerzuk]

I have an MEP004 that I have finally got to run, but have no power output. Where can I access the procedure to flash the field? And while I'm about it, what do I use for search words to find Sewerzuk's video?

Thanks,
Carroll

I have several of my generator videos here:
http://www.steelsoldiers.com/auxillary-equipment/77132-mep-operation-testing-video-thread.html

most of them demonstrate the proper way to start up an MEP.

 

[Motownmike]

Standalone meter

Hi Sewerzuk, I do have a Fluke here that can check the freq, my fingers were getting too cold out there so I gave up for the evening. We've got a pretty stiff wind blowing out here and I can't fit the set into the barn without removing the stacks.
I'm pretty happy with the condition of this set, It fired up with barely a touch of the start switch, which surprised me!
The Deka batteries that came with it were down to .65 volts each (!) I have a charger over here that can recharge practically dead batteries, made by Soniel, I think. I left it charge for a night and a day and they seem to be good to go, still have to check the cells S.G. though.
Tomorrow I plan on messing with it some more and hooking up the O-scope as well. I want to caulk up the seams on the stacks to help prevent water entry, there seem to be little nooks and crannies that let some moisture in here and there.
I think I got the best of the bunch that were selling in Lansing. I inspected them all, and even though this one had more hours than one or two of them, the general condition is excellent for a set this age.
Thanks also to Pete & Ken!
Mike

 

[1942 Mk1]

Thank you PeterD and Sewerzuk,

Your response(s) gives me answers and insight. The explanations in text and videos clear up some fuzzy areas. Will post findings as soon as time permits me to do these tests.

Sugaring season is approaching fast. I have been working in the woods the last 6 weeks on pipeline maintenance and new installation. I still have the Thiokol in the shop un-finished, the snow fall hasn't been great, so have not really applied myself to the inside work.

This MEP-004 is to be a back-up gen for the sugarhouse, and a back-up power supply for my house in the event of a power outage. When I got it (July 2011) it would not start. I cleaned the water separator, renewed fuel filters, bled fuel system, hot wired the shut-off solenoid, nothing I did would permit fuel at the nozzles. Sent the IP to diesel shop, and $980.00 later, it started and ran flawlessly.

The next problem to overcome was it wasn't producing power. It just may in fact be that I didn't hold the start switch in long enough to excite the field. I have read things that didn't sink into this skull until your answers pointed out things to me.

I have done searches here, but have not had much success, (not too computer literate), but the subject matter of this thread prompted a perfect opportunity for me to open the inquiry.

Many thanks again for the timely responses, and I will keep you posted.

Carroll

 

[Motownmike]

No Field Flash

Well, I went out today to do some more checking on the set. When I tried to flash the field, the starter would just grind on the flywheel, and I couldn't flash the field.
For some reason the starter is engaging while the engine is running and I push the switch up, I tried it a couple more times with the same tooth grinding result. It was about 10 or 15 degrees cooler that yesterday. I was thinking the solenoid was sticking, or a relay is not working properly.
I went throught one of the manuals I downloaded but did not see any component locations, I see the K5 relay is the field relay on the schematic, but don't know where it is on the set.
Or am I going in the wrong direction?
Mike

 

[sewerzuk]

Well, I went out today to do some more checking on the set. When I tried to flash the field, the starter would just grind on the flywheel, and I couldn't flash the field.
For some reason the starter is engaging while the engine is running and I push the switch up, I tried it a couple more times with the same tooth grinding result. It was about 10 or 15 degrees cooler that yesterday. I was thinking the solenoid was sticking, or a relay is not working properly.
I went throught one of the manuals I downloaded but did not see any component locations, I see the K5 relay is the field relay on the schematic, but don't know where it is on the set.
Or am I going in the wrong direction?
Mike

This narrows the list down a lot; either your set is throttled clear down to idle and turning at such a slow speed that it isn't tripping the speed switch (which is supposed to prevent the starter from grinding), or the speed switch itself is defective.

I believe the same speed switch ALSO has a contact in it that doesn't allow the field flash until the genset has come up to speed; the same speed that the starter is supposed to disengage at.

So, you have 2 symptoms pointing toward the same component; no field flash and no starter safety.

I would try throttling the set up to a higher RPM and try to reflash the field. If the starter still grinds, you may have a defective safety switch.

 

[Motownmike]

Reset switch?

Thanks Sewerzuk, I will give that a try when I get home from work today. I'm worried that I messed something up, the throttle control was all the way in and since there is no tach on this, I left it there for half an hour while I checked for leaks. I'm thinking of installing an add-on tach and freq meter.
It does have one of the matched set frequency transducers so I'm thinking it's the low throttle speed that's the culprit.
I understand that there might be a reset button on the left side of the engine (air cleaner side) that may also be the culprit.
Well at least it was working a couple days ago, hopefully just a simple mistake or old switch failing. By the way where is the speed switch, is it the same as the overspeed switch that's supposed to be on the left side of the engine? The manual I downloaded is not very detailed.
Mike

 

[PeterD]

I agree with Sewerzuk, I think your engine is running at way too low RPMs. Certainly with the throttle pushed in full way, it is very possible. Does the engine seem to be running fast, or slow (tough without experience or a tach, but...) You want it at 1800 RPM to generate 60 Hz power, but any engine speed between 1500 and 2000 will be a starting point.

What I've done, and I know a few others too, is to pull out the throttle half way. That seems to work well as a starting point.

 

[sewerzuk]

Thanks Sewerzuk, I will give that a try when I get home from work today. I'm worried that I messed something up, the throttle control was all the way in and since there is no tach on this, I left it there for half an hour while I checked for leaks. I'm thinking of installing an add-on tach and freq meter.
It does have one of the matched set frequency transducers so I'm thinking it's the low throttle speed that's the culprit.
I understand that there might be a reset button on the left side of the engine (air cleaner side) that may also be the culprit.
Well at least it was working a couple days ago, hopefully just a simple mistake or old switch failing. By the way where is the speed switch, is it the same as the overspeed switch that's supposed to be on the left side of the engine? The manual I downloaded is not very detailed.
Mike

The -004's VR isn't as sensitive to idling as the -002/-003 one. I would guess your machine is still OK, especially if it was going so slow that the field wasn't flashing (if the set isn't making power, there is ZERO strain on the VR). Extended idling wouldn't account for the issues you're having with the speed switch, anyway. The fact that your starter motor isn't disengaging tells me that the field flash isn't happening. So, until you can get the set started without the starter motor grinding, it will probably never make power...and the frequency meter won't ever indicate anything! I think you should fire the thing back up and bring the RPM's way up, then try the field flash again...

I'm not aware of any reset button inside of the generator; at least I have never run into one. Not sure what it would reset over there anyway? Does your set actually have a button, or did somebody else suggest it?

The speed switch is on the same side of the engine as the air filter; it screws into the side of the block, and has a connector with several wires connected to it.

One other thought...maybe there is some confusion with how to adjust frequency? That little knob on the control panel that is labelled "frequency adjust" doesn't do anything on a utility set. The way you adjust frequency is only with engine RPM...

 

[PeterD]

...

I'm not aware of any reset button inside of the generator; at least I have never run into one. Not sure what it would reset over there anyway? Does your set actually have a button, or did somebody else suggest it?

The speed switch is on the same side of the engine as the air filter; it screws into the side of the block, and has a connector with several wires connected to it.
...

And a push button on the top to reset it if there is ever an over-speed condition, so perhaps that is what he's referring to as the reset button?

I too should have mentioned the bogus frequency control on the panel! I'm sure that confuses a lot of people who don't know that adjustment is only for the precise sets, not the utility MEP-004.

 

[Motownmike]

Thanks PeterD & Sewerzuk!

As soon as I got home, I pulled the throttle halfway out, checked the overspeed reset (yes that's what I was referring to) disconnected and reconnected the canon plug and fired her up. Starter dis-engaged properly and the frequency meter went straight to 62 HZ. I adjusted the throttle down and it stabilized right at 60HZ.
It was that simple, my bad...
Thanks to both of you for taking the time and spelling it out to me.
I knew about the variable frequency knob being inoperative from the manual I downloaded. I was just hesitant to throttle up the set without knowing what I was doing.
Anyways, I'd be scratching my head for a while if it wasn't for this site and specifically both of you helping.
When the snow melts around here I will look into converting it to single phase.
Mike

 

[PeterD]

... Starter dis-engaged properly and the frequency meter went straight to 62 HZ. I adjusted the throttle down and it stabilized right at 60HZ...

Everyone loves a happy ending!