I was going to ask how everyone was slaving generators over with external batteries and connecting battery connectors. Is electrical taping the terminals together enough? Or is removing the terminals, bolting the lugs together, and then covering in electrical tape preferred?
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Slave plug for MEP genset - cost effective options(?)
- Thread starter Ray W
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I drop the positive into a glove while I'm testing.
Evvy Fesler
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Yikes! Don’t allow them to touch each other and don’t allow the positive to touch anything. What they meant by taping was to tape each one individually to prevent the lugs from shorting out.
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Tape works just fine. But don't be cheap with it. Tape is way more less expensive then a connector.
Tape = Electrical type tape on each battery connector individually. You don't need them bouncing around touching stuff inside.
The slave receptacle on each MEP is a direct 24v input and output. Actually, all military hardware that has engines, has a 24v slave port. On trucks, lots will have the 24v impact tool. Plugs onto the 24v slave port to change your tires, etc...
It allows a running Military item to use the slave port and cable to start another item.
Running HMMWV to start a generator, or another truck.
The slave receptacle on each MEP is a direct 24v input and output. Actually, all military hardware that has engines, has a 24v slave port. On trucks, lots will have the 24v impact tool. Plugs onto the 24v slave port to change your tires, etc...
It allows a running Military item to use the slave port and cable to start another item.
Running HMMWV to start a generator, or another truck.
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OK, time to reignite an issue...
The issue is:
will a MEP-XXX run WITHOUT slave cable or batteries after a slave start. Read above for opinions and below for my real world issue.
Today I got around to firing up a MEP-802A I picked up a couple of months ago. I used a slave plug.
Unit started and ran fine using slave plug with external batteries. Internal battery leads were taped up securely as GUYFANG suggested.
Unit was running great so I disconnected the slave plug and let the unit run while I was elsewhere.
Unit shut down after about 4-5 minutes.
Thinking this was strange I hooked everything back up and restarted the unit.
Unit started and ran fine.
I unhooked the slave plug and kept an eye on the unit.
After 4-5 minutes the low fuel light came on with a flicker and the unit shut down.
I reattached the slave plug and started the unit.
It started fine.
I unhooked the slave plug and the unit ran for 4-5 minutes then shut down.
This was the third time it shut down when the slave plug was removed and no internal batteries attached.
I hooked up the slave plug again, started the unit and let it run. With the slave plug attached to external batteries, the unit ran with no issues until I manually shut it down. (A)20min.
In order not to dedicate two batteries to it, I had hoped to be able to start it via my slave plug, remove the slave plug and let it go, but it appears that wont work.
By the above testing, it appears the unit must make some type of electrical circuit via the batteries(either internal or slave) when the unit is running in order for the fuel pump to work properly. Im guessing 4-5 minutes is just about enough time to empty the fuel lines and filter absent the pump working which is why it kept shutting down when no batteries/slave was attached.
Any thoughts?
The issue is:
will a MEP-XXX run WITHOUT slave cable or batteries after a slave start. Read above for opinions and below for my real world issue.
Today I got around to firing up a MEP-802A I picked up a couple of months ago. I used a slave plug.
Unit started and ran fine using slave plug with external batteries. Internal battery leads were taped up securely as GUYFANG suggested.
Unit was running great so I disconnected the slave plug and let the unit run while I was elsewhere.
Unit shut down after about 4-5 minutes.
Thinking this was strange I hooked everything back up and restarted the unit.
Unit started and ran fine.
I unhooked the slave plug and kept an eye on the unit.
After 4-5 minutes the low fuel light came on with a flicker and the unit shut down.
I reattached the slave plug and started the unit.
It started fine.
I unhooked the slave plug and the unit ran for 4-5 minutes then shut down.
This was the third time it shut down when the slave plug was removed and no internal batteries attached.
I hooked up the slave plug again, started the unit and let it run. With the slave plug attached to external batteries, the unit ran with no issues until I manually shut it down. (A)20min.
In order not to dedicate two batteries to it, I had hoped to be able to start it via my slave plug, remove the slave plug and let it go, but it appears that wont work.
By the above testing, it appears the unit must make some type of electrical circuit via the batteries(either internal or slave) when the unit is running in order for the fuel pump to work properly. Im guessing 4-5 minutes is just about enough time to empty the fuel lines and filter absent the pump working which is why it kept shutting down when no batteries/slave was attached.
Any thoughts?
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Your battery charging alternator is not putting out, or the FU-1 fuse is bad/missing. The set should run on just the battery charging alternator. Says so in the TM.
Scoobyshep
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Guy beat me to it... quick and easy test, turn on the panel lights and see if they go out when the batteries are disconnected. Long term I would be interested in the DC voltage.
Ray70
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Sounds like you have some kind of alternator issue going on... However...
It can not simply be that the alternator is dead or fuse is blown because you are not just using up the residual fuel left in the lines.
You need a substantial amount of current at 24V to keep the fuel solenoid open, so a completely dead alternator should shut down as soon as you pull the slave plug due to the solenoid shutting down.
Next time you start it, with batteries installed, take a look at the ammeter and see what it says, are you above or below Zero?
You should start out at about +20 and fairly quickly drop back to +5 for a few minutes and soon be back to Zero.
You should never be below zero, otherwise you have a charging problem.
I would think your alternator is probably working a little, but not enough to satisfy everything that needs 24V to keep you running without any batteries installed.
It can not simply be that the alternator is dead or fuse is blown because you are not just using up the residual fuel left in the lines.
You need a substantial amount of current at 24V to keep the fuel solenoid open, so a completely dead alternator should shut down as soon as you pull the slave plug due to the solenoid shutting down.
Next time you start it, with batteries installed, take a look at the ammeter and see what it says, are you above or below Zero?
You should start out at about +20 and fairly quickly drop back to +5 for a few minutes and soon be back to Zero.
You should never be below zero, otherwise you have a charging problem.
I would think your alternator is probably working a little, but not enough to satisfy everything that needs 24V to keep you running without any batteries installed.
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Don't rule out a flaky connection somewhere. Could be a loose terminal on the back of the alternator.
Assume nothing.
Assume nothing.
Thanks for all the suggestions, they are much appreciated.
Went thru all of the connections today. Checked fuses. Checked alternator belt.
Started the unit and removed slave cable connection. No batteries attached.
Unit ran like a boss and didn't shut down til I shut it down (after about 25 minutes).
I don't know what caused the original shut-down issue, but I'll guess something just may have not had good contact.
Ill take it either way; as I like this little guy.
Best to all.
Went thru all of the connections today. Checked fuses. Checked alternator belt.
Started the unit and removed slave cable connection. No batteries attached.
Unit ran like a boss and didn't shut down til I shut it down (after about 25 minutes).
I don't know what caused the original shut-down issue, but I'll guess something just may have not had good contact.
Ill take it either way; as I like this little guy.
Best to all.
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Nice job.
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I chased a problem on a 60 KW for months. It ran a week, it ran 5 min, it ran a day, it ran 20 sec, it ran 2 weeks, and so on. Then shut off. You have a problem in the set. Its not going to go away. Its not going to fix itself. Sooner or later, its going to drive you crazy. You need to find it.
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Now I can finish my thoughts. The Oberbefehlshaber, was exercising maximum pressure to move out. So I could not put everything down here that I wanted.
We are missing something here. On my walk, I thought about it. We are fixed on the idea that the Battery charging alternator, is bad/weak, or that we have a loose wire. And we might. But think about this.
The top 4 faults, shut the engine down. In your case, that might be happening. Since you have no batteries in the set, as soon as the engine get shut down, the exciter voltage to the battery charging alternator get shut off also. When that happens, there is no 24 VDC being supplied to the Fault indicator. And you do not get to see what idiot light comes on. I am not saying this is happening. But I will say its a good chance that it is. So what you need to do is put batteries in the set, and see if it will run 30-40 min, without failing. Or, hook up a slave cable, to a 24 VDC system, and leave it hooked up. Start the set, and see if it runs 30-40 min. The added benefit to this way, is that you can watch your battery charging meter, and see if it goes up to about 10? or what ever, stay there a while, and then slowly come back down. That will prove that your Battery charging altnerator is funtioning correctly.
We are missing something here. On my walk, I thought about it. We are fixed on the idea that the Battery charging alternator, is bad/weak, or that we have a loose wire. And we might. But think about this.
The top 4 faults, shut the engine down. In your case, that might be happening. Since you have no batteries in the set, as soon as the engine get shut down, the exciter voltage to the battery charging alternator get shut off also. When that happens, there is no 24 VDC being supplied to the Fault indicator. And you do not get to see what idiot light comes on. I am not saying this is happening. But I will say its a good chance that it is. So what you need to do is put batteries in the set, and see if it will run 30-40 min, without failing. Or, hook up a slave cable, to a 24 VDC system, and leave it hooked up. Start the set, and see if it runs 30-40 min. The added benefit to this way, is that you can watch your battery charging meter, and see if it goes up to about 10? or what ever, stay there a while, and then slowly come back down. That will prove that your Battery charging altnerator is funtioning correctly.