MEP-003 overcharging the batteries

[texascadillac42]

After running my newly acquired MEP-003 for 2 hours or so today, I noticed that the battery voltage gauge was fluctuating quickly, from the green to the red "overcharge" zone. Confirmed this with a voltmeter on the batteries, which showed 30 volts. I searched and read a thread or two about DC voltage regulators going bad, as well as the capacitor which is hooked to them.

I believe one of these 2 components is the problem with mine, but the other threads did not mention a fluctuating voltage gauge, just one that stayed over towards the red, overcharge, side of the gauge.

I also have a spark when connecting the battery cables to the unit, which was another symptom of a bad component in the system.

Any other thoughts? I am going to pull the cover off the VR tonight and examine the wires for any obvious problems, and will post my findings.

 

[Speddmon]

probably the VR going bad. The capacitor is only in the circuit to protect the VR from spikes and surges. The diodes in the VR can go bad in 1 of two ways...open, meaning no voltage out of the VR, or shorted meaning too much voltage and something akin to the AC going into it getting to the batteries.

 

[Carl_in_NH]

The spark may or may not be an issue when you connect the battery cable; charging a functioning electrolytic cap will cause a little spark, too.

You can check with your amp meter and see how much current the generator is drawing from the battery steady state with the master control switch in the 'off' position. Should be close to zero once that cap charges - but could also be a small number, like a milliamp or two.

If you see a current draw, disconnect the cap from the charging regulator and see if the current drain goes away; if so, the cap is leaky and you should replace it.

My guess? I suspect your charging rectifier / regulator assembly is what's toasty.

 

[texascadillac42]

I hope to pickup my other 2 003 units tomorrow or Friday. I suppose I could just steal one of the VRs from them to try it out....

I pulled the fan shroud off to get a better look at what is going on in there. In another thread discussing the same issue I thought I read that the capacitor should have one wire going right back to the mounting screw for grounding purposes. My unit does not have that. Also, there is a longer tube like thing mounted below the VR with one wire on each end of it, what does this thing do?

It was at an angle and the outer "tube" portion of it was up against the terminal that one of the wires coming out of this tube was hooked up to. I wonder if this shorted something out?

I can post a pic of what I am talking about if it helps. Thanks.

On edit, is the long tube thing under the VR the capacitor? I assumed it was the cylinder piece that was on top of the VR, but directly attached to it....

 

[coyote62ny]

had the same problem with my mep-003 the long tube with a wire coming out of each end is the capicitor sounds like your vr is shot mine charged at 30 volts as well it ended up being the vr changed the vr now it charges at 28 volts gauge stays at the uper edge of the green you are lucky to have a extra set to get parts from i had to buy a new vr it cost 130.00 if you want to get a used one so you dont have to rob one from another set try tomBadgett atgulf coast trucks office number is 1-281-422-3200 cell1-832-323-1445 he tests all his used parts on a gen set to make shure they are good he is the cheapest i have found for used parts for these sets hope this helps

 

[texascadillac42]

I don't really have an "extra" set, I bought 3 sets total, but really I need all 3 to be working, useable sets. Thanks for the phone number, I will definitely call him as soon as I confirm that my VR is bad. $130 isn't too bad for a new one if I have to go that route though.

 

[coyote62ny]

the place i got my vr from was southern automotive wholesalers pontiac mi. phone number 1-248-355-5555 their stock number is s.a.w 10385252 part no. fvr-4006 i remember the guy i talked with said they only sell to private people through ebay so he put one on ebay so i could get it.the only real test you can do is to test the stator with the shroud off remove the wires that go to the vr and test the two stator wires as follows start generator test stator wires for voltage it should be 30 to 35 volts ac across the two stator wires DONT RUN THE GEN SET MORE THAN 2TO3 MIN. or you will over heat the engine and be careful about loose clothing so you dont get caught in the blower wheel as far as testing the vr with an volt ohm meter the guy at southern automotive told me there really wasnt any way to test the vr without complicated equipment they should know they made the vr or you could just get a 6 amp battery charger that will charge 24 volt batteries and plug it into the 120 outlet on the generator i just wanted mine to be the way it was supposed to be hope this helps

 

[texascadillac42]

I appreciate the help. I am probably going to end up ordering a VR and capacitor tomorrow and getting this thing ready to work.

 

[coyote62ny]

the surplus places want 50.00 for the capacitor you can go to an electronics supply store and get a capacitor that is 75 volts 50 microfarids 3/8 inch in dia. will fit the mounting bracket that the old capacitor was in you will have to solder wires on the new one make shure you get the + side of the capacitor on the terminal that the battery wire is hooked to this wire has a red band on it just above the connector the electronics stores sell these for 3 to 5 dollars a lot cheaper than used surplus