mep-003 still over charging batterys

[coyote62ny]

replaced vr and capacitor got the parts from delks called delks talked to william he thought the problem was bad ground at the grounding lug and the cables that hook to it and the frame cleaned those and checked the output of the stator at the terminal block with it running voltage at 31 volts ac generator is grounded to a ground rod still goes to 31 volts across the batterys when running help please dont know what else to do thanks dean

 

[Speddmon]

IIRC the batteries ground through the starter frame and not the grounding lug on the frame. The slave cable grounds at that grounding lug, but from the factory the battery negative cable only goes to the starter mounting frame. The grounds are a possibility, but I'm willing to bet your VR is still no good. If you got 31 volts at the DC alternator, the regulator should rectify and drop it to around 28 volts or so.

 

[coyote62ny]

im thinking the same thing but i dont know if delks will take this one back i was also wondering where else you can get the capacitor as i still have the sparks when i put the battery cable on thanks speddmon

 

[coyote62ny]

William at delks said the sparks are normal my lawn tractor dont do that

 

[coyote62ny]

could someone tell me how the wires go on the terminal block for the vr mine has the capacitor hooked to the wire with the red band on it and to the terminal mounting screw ground the tm it looks like it is hooked to the bottom right terminal and ground but the in the picture the wires are all mixed together and you really cant tell whats what thanks

 

[coyote62ny]

sorry not bottom right bottom left

 

[Speddmon]

First off, the sparking is NOT normal. If you have sparking then you have some kind of unwanted draw on your batteries.

The capacitor is nothing more than a 50 Microfarad 75 volt DC capacitor. Available at just about any place that sells electronics components on the internet. E-bay would probably even have some listed.

Also, it sounds like your capacitor is hooked up correctly. One lead of the capacitor should be on the mounting screw of the terminal strip effectively grounding that side of the capacitor. The other end should be hooked up with the VR lead with the red band.

Go through like I told you in your previous post and determine which one of them is causing your sparking. But I'm willing to bet that if you are still charging at over 30 volts it's the VR causing the problem again.

 

[PeterD]

What are you measuring the voltage with? Make sure your meter is accurate--it would not be the first time that someone was thinking high (or low) voltage and only found out later the meter was off, not the voltage!

 

[coyote62ny]

checked it with two meters both good meters also shows high on the meter in the gen set ordered a brand new vr today from the company that made them for the military try that and see what happens thanks for the help

 

[coyote62ny]

if you unhook ground end of the capacitor no more sparks so the capacitor is bad but can you still use the generator with out hurting anything maybe just disconnect the battery when you shut it down thanks

 

[kipman]

How much for the new VR?

 

[Speddmon]

I hadn't thought of it until just now, but the way the capacitor hooks into the system, if the output transistors of the VR are shorted in just the right way, that could be allowing the current to flow from your positive lead through the shorted transistors in the VR and through the capacitor...the sparking may not be coming from a bad capacitor at all.

 

[coyote62ny]

thanks for the reply speddmon got a new capacitor just in case 2.66 cheap enough hope i can get this charging system figured out man that mep runs good . i got the vr from southern automotive wholesalers on e bay they cant sell to private people direct you need to type in this number with the spaces to find it 2920-01-038-5252 cost me 140.00 with shipping but i could not find a new one anywhere else if i can find someone with a digital camera i will post pics of my mep-003 thanks everyone

 

[coyote62ny]

they have 6 more voltage regulators left

 

[PeterD]

Just a point of interest. A good capacitor will spark when power is applied. Then if power is applied again it (assuming nothing discharges the capacitor) it won't spark. An open capacitor will not spark. A shorted capacitor will spark, then often times go bang. A leaky capacitor will spark and draw current.

The best way to test is to use an inline (or clamp-on DC) ammeter and monitor the power draw after the batteries are connected. An acceptable draw with everything off is about 40 MA maximum.

 

[Sarge29]

What does the capacitor do for the charging system? Can it be eliminated and everything still work OK?

 

[coyote62ny]

i was wondering the same thing a friend thats into electronics said it looks like they are using it to filter out unwanted ac noise

 

[Polycop]

My 003a sparks when I disconnect the batteries and I'm pretty sure it is charging right. That being said, I unhook the batteries when I'm done using it. In addition, I'm ordering a 750 amp battery disconnect switch (to make it easier) and a Solargizer (to keep them topped off).

 

[PeterD]

i was wondering the same thing a friend thats into electronics said it looks like they are using it to filter out unwanted ac noise

As an EE I will confirm that as why. Also there is little about that capacitor that makes it special, and there are a lot of substitutes you can use in a pinch if the capacitor is bad.

Side note: capacitors fail in one of two ways:

Open/low capacitance failure: The capacitor opens or has a much lower capacitance. This is roughly the equivalent to the capacitor not being there.

Shorted failure: a total short, or a low resistance. Normally when a capacitor is charged fully, it will become a very high resistance (you can confirm this with a standard analog multi-meter, the resistance reading starts low, then raises higher as the capacitor charges.) When a capacitor is shorted or has low resistance you risk a messy failure--they can explode with a messy bang. They will usually get hot as well.

It is also possible to have both types of failures in the same unit. So a capacitor will have low capacitance and exhibit a low resistance short too...

With some voltage regulators it is important to not put the capacitor on the wrong regulator terminal. Doing so will damage the regulator (the capacitor causes the contacts in the regulator to excessively arc and fail.)

 

[Sarge29]

I am not that good with electronics but understand the electrical side so I have to ask. Will it do any damage to just eliminate the capacitor? Is the AC noise detrimental to other things on the gen?