MEP-802a AC disengages when I release the switch

[mikejoconnor]

hey all, I'm looking for some input.

I just picked up a MEP-802a. Replaced all the fluids/filters, added batteries and it started up. The connivence outlets produce 60 hz and L1-L3 is dialed in to 240 volts. However when I try to engage the AC, the light only comes on if I hold the switch in the up position. Battle Short mode does not effect this. I tried removing and cleaning the k1 relay, but that didn't do the trick.

Any suggestions?

attached is a picture of the K1 relay. Are any wires suppose to be connected to the two screws on top?

 

[peapvp]

Could you please post picture{s} of the inside of your cubicle? Thanks

 

[Ray70]

I once had an 802 doing the same thing. In my case it was a faulty short circuit / overload relay.
The TM tells you how to test the K4 Circuit interrupter, but if your light illuminates the relay has to be working because the light is powered by a switch inside K4 that closes when K4 pulls down.
Also check the wiring and the diode on S1 start switch, but my money is on the overload relay not allowing K4 to latch on.

 

[kloppk]

For starters check to be sure there is a diode installed on S5.

Only 4 of the 6 small terminals on K1 are used. The lone two small ones are not used.

 

[Guyfang]

Have you ever seen this set work right?
Or is it new to you?
If its new, look for the diode on S5, like Kurt wrote, but ALSO, check to see if the S5 is wired correctly.

 

[mikejoconnor]

Thanks for the feedback. It is new to me.

I'll check S5, k4, and the overload relay. More pictures are attached.

 

[zarathustra]

The circuitry to hold the K1 contactor shut is fairly straightforward. It is only complex in that the generator has built in overload / short sensing circuitry that will shut the AC off if a fault is detected. I do not believe that the Battle Short switch will override that fault.

The S5 switch energizes the K1 relay. When that happens it also engages contacts in the engagement circuitry will keep K1 on when the switch is released. That circuitry runs to and through the normally closed S5 terminals and several (4, as I remember) terminals on the overload detection module..( that's the black module on the far left of the inside of the control box).

If anything in the "engagement circuitry" opens up then the K1 shuts off.

If you use the schematics to draw a block diagram on how the engagement circuit works it would be easy to trouble shoot.
The problem I had was a marginally bad S5, but I wouldn't start replacing things 'till I discovered the cause.

Good luck...

 

[Light in the Dark]

If you end up with a problematic overload, I might be able to assist in a replacement for you. New/open box for that unit are up on the big auction site 350-400.

 

[peapvp]

One of the more common failures is this Diode on the S5 switch - test the Diode if you haven’t done so.

 

[peapvp]

Plus it appears that this diode is installed backwards

 

[Guyfang]

Thats what I saw when I looked at the pictures in post #6.

Thats why post #5 is always the first step. Check the wiring against the schematic. And when ever the S7 will not bypass a fault, CHECK THE WIRES.

Clean looking set!

 

[mikejoconnor]

Plus it appears that this diode is installed backwards

That was the ticket. Thanks.

That diode was bothering me, but I had not yet made the connection. Turned it around and all is well. Now I need to put it under some load, because apparently it's done nothing but idle for 98 hours.

 

[Guyfang]

Gen sets are not to be idled. They should never run with less the 60 hertz on the meter.

Or do you mean its been run, without supplying a load. Some how that rings wrong. Someone turned the diode around. By accident or on purpose.

 

[Light in the Dark]

Someone turned the diode around. By accident or on purpose.

I'd say thats par for the course on some items being moved out these days. Either trash machines, or purposely made to not function with small changes like this.

 

[Guyfang]

Can you blame a unit? The MEL lets them get something new, instead of continuing to run and support something that is on its way out, and repair parts are no longer being procured.

 

[peapvp]

That was the ticket. Thanks.

That diode was bothering me, but I had not yet made the connection. Turned it around and all is well. Now I need to put it under some load, because apparently it's done nothing but idle for 98 hours.

@mikejoconnor,

I think it was about 4 or 6 years ago when a Staff Sergeant from Edwards AFB called me. They had 6 or 10 802/803 units they were retrofitting with our Auto Start Board and they were testing the Gensets prior to installing our boards to run manually and had the same problem.
The Gensets were brand (no reset) new and had 3 hours on them.
If they had 6 or 10 them at Edwards, then there where probably more.

It was my understanding that those had a delivery date between 2006 and 2011 and had been stored for later use.
I am not sure on how this internal Process Works.

Peter

 

[Guyfang]

I would think that between 10-15 thousand 5 & 10 KW gen sets were procured. Most go to units and get used. Some, go into storage, for use later on. Some go into storage in a Supply activity, waiting for someone to drop a requisition. Some go into storage, like on board ships, waiting for a deployment, or some other reason to come out of storage. But what ever happens to them, when they get turned into the supply system, they make a stop at DRMO, or what ever its called today. There, they spend at least 90-120 days. After that time is up, they might get sold, might get DEMILLED. So, lets say a set hits DRMO in Germany. Someone in Korea, needs a set. They can:
1. Request through the normal supply system, a gen set. The Item Manager looks in his high speed, low drag computer, and sees one in Germany, condition code A. He sends a request to the German DRMO to send the gen set to the SSA, (Supply Support Activity) that services the needing unit, and away it goes.
2. The unit in Korea needs a gen set. It it turns in one, unserviceable, to the supply system, and the Battalion S4, (Supply Wiesels) are on the ball. They look in in the high speed computer and see one is in the DRMO in Germany, and send in a request. The Item Manager looks in his computer and sees no other condition code A gen set anyplace closer, and hacks off on the request, and away it goes.
3. The unit in Korea needs a set. They go to DRMO, and ask if there is one available. The DRMO says, "No, not here, but, we found one in Germany. Do you want it?" The unit says "Roger" and it will get said gen set ASAP.

Anything you get from DRMO cost the unit NOTHING. Not a penny. If its a Property Book Item, (that means it is accountable) it needs needs to be added to the requesting units Property Book.

So, where am I going with all this? Say a gen set, or sets, are in storage. The CECOM, (people responsible for Power Generation in the Army) have a fielding plan for the new gen sets being slowly but surely issued to all units and activity's in the Army and or Military. They try to send gen sets that are in good shape to units or activity's needing them. Edwards could have been issued the sets from DRMO, or a SSA, to replace worn out or non repairable sets. Or some new project was created, and they submitted a request for , "Gen Set, 10 KW". They might not have been high enough up on the totem pole to get the new issued gen set, and the Supply system will issue what ever fits the bill. It may not have the same NSN you ordered, but will properly fill the need you have.

Oh, only a fool believes the TTM. Time Totaling Meter.

 

[peapvp]

I would think that between 10-15 thousand 5 & 10 KW gen sets were procured. Most go to units and get used. Some, go into storage, for use later on. Some go into storage in a Supply activity, waiting for someone to drop a requisition. Some go into storage, like on board ships, waiting for a deployment, or some other reason to come out of storage. But what ever happens to them, when they get turned into the supply system, they make a stop at DRMO, or what ever its called today. There, they spend at least 90-120 days. After that time is up, they might get sold, might get DEMILLED. So, lets say a set hits DRMO in Germany. Someone in Korea, needs a set. They can:
1. Request through the normal supply system, a gen set. The Item Manager looks in his high speed, low drag computer, and sees one in Germany, condition code A. He sends a request to the German DRMO to send the gen set to the SSA, (Supply Support Activity) that services the needing unit, and away it goes.
2. The unit in Korea needs a gen set. It it turns in one, unserviceable, to the supply system, and the Battalion S4, (Supply Wiesels) are on the ball. They look in in the high speed computer and see one is in the DRMO in Germany, and send in a request. The Item Manager looks in his computer and sees no other condition code A gen set anyplace closer, and hacks off on the request, and away it goes.
3. The unit in Korea needs a set. They go to DRMO, and ask if there is one available. The DRMO says, "No, not here, but, we found one in Germany. Do you want it?" The unit says "Roger" and it will get said gen set ASAP.

Anything you get from DRMO cost the unit NOTHING. Not a penny. If its a Property Book Item, (that means it is accountable) it needs needs to be added to the requesting units Property Book.

So, where am I going with all this? Say a gen set, or sets, are in storage. The CECOM, (people responsible for Power Generation in the Army) have a fielding plan for the new gen sets being slowly but surely issued to all units and activity's in the Army and or Military. They try to send gen sets that are in good shape to units or activity's needing them. Edwards could have been issued the sets from DRMO, or a SSA, to replace worn out or non repairable sets. Or some new project was created, and they submitted a request for , "Gen Set, 10 KW". They might not have been high enough up on the totem pole to get the new issued gen set, and the Supply system will issue what ever fits the bill. It may not have the same NSN you ordered, but will properly fill the need you have.

Oh, only a fool believes the TTM. Time Totaling Meter.

Guy, I am glad we were able to amuse you. I will email the Staff Sergeant and see if he wants to put in his 25 cents in!
Peter

 

[Guyfang]

We used to have a gen set, a 52300. It was a 45KW, 400 hertz set. They were older then dirt. Great sets. But the Army was getting rid of them. They had lots of problems, but it was always penny anti stuff. I only saw one engine destroy itself. And it had max help from a guy who simply went over the edge. he drained the oil, and jumped the LOP. Anyway, one of my sets had the serial number of 303. It was so old, the Lord learned on it. We got a TWIXT, (early e-mail) in 1974, to turn in all 52300 sets with over 10,000 hours. Old 303 was my baby. I loved that set. So I went out to a 3 KW, took out the TTM that read 350 hours, put it in 303 and never looked back. My CWO, just smiled and went the other way. We kept 303 until mid 1977. She had way over 20,000 hours by then. But the TTM read maybe 8,000. See the last sentence of the previous post!

 

[peapvp]

@Guyfang what gigglywater are you consuming tonight?