MEP 701 VR2 wires

[The_New_Guy]

Okay. I'm going to be up front here with the hope it provides context for the help I am looking for and not a bunch of rediculous comments suggesting I shouldn't even own a MEP. Thank you in advance.

I am not an electrician or engineer. I don't have any years of service and only own one piece of milsurp equipment. I am, however, reasonably handy and a long time reader of steelsoldiers and I think you guys are pretty great.
Here in South Dakota, we tend to get winter storms that knock out power for hours to days to weeks. I have been using a MEP701A in 120v 1ph to run the household essentials for a number of years.

During the spring oil change and test run, I noticed the voltage would creep up continuously. So, I opened the panel to start poking around for any obvious issues. Once inside, I noticed a wire that burned the sheathing off and damaged the sheathing on two other wires. The burned wire goes from the part labeled A1-VR2 and I believe is wire labeled A1-TB2-9.

The diagram seems to show this as a - not a + wire.
So, here is where I think I am at:
1. I think I need a new VR and will swap in a SX460 clone.
2. Is the VR2 likely fried? Only the VR2 or both?
3. What the hell does the VR2 do and do I need it if I swap to SX460?
4. Clear diagrams and/or descriptions are appreciated.

Open to anything helpful.
Thanks!

 

[peapvp]

Hi,

your 701A is a 016A with ASK if I am not mistaken

All 016A Manuals; Wiring Diagrams are pages FO1 and FO2 in the first two manuals listed

VR1 is VAR and VR2 is alternator Voltage Regulator

 

[The_New_Guy]

Thanks. I think it is a 16B in an ASK and I do have the TMs for it. Unless I missed it, the TM doesn't really state what role the VR2/alternator(?) fills.
Do you have any thoughts why that wire out of it would have burned up?
Thanks.

 

[peapvp]

Thanks. I think it is a 16B in an ASK and I do have the TMs for it. Unless I missed it, the TM doesn't really state what role the VR2/alternator(?) fills.
Do you have any thoughts why that wire out of it would have burned up?
Thanks.

I looked at the Wiring Diagram for 016A. I am not sure if there are differences between the two. I do not have the TM’s for the Bravo unit.
The legend is printed on each diagram to identify components properly.
The alternator charges your batteries. Same as in any car. And VR2 is the regulator for that.

 

[peapvp]

I looked at the Wiring Diagram for 016A. I am not sure if there are differences between the two. I do not have the TM’s for the Bravo unit.
The legend is printed on each diagram to identify components properly.
The alternator charges your batteries. Same as in any car. And VR2 is the regulator for that.

I need to correct myself. I looked at both manuals, Alpha + Bravo.
The second listed TM is the Bravo manual.

 

[peapvp]

Thanks. I think it is a 16B in an ASK and I do have the TMs for it. Unless I missed it, the TM doesn't really state what role the VR2/alternator(?) fills.
Do you have any thoughts why that wire out of it would have burned up?
Thanks.

Here is test of VR2




Wires usually burn when the current going through the wire exceeds the amount of current the wire can handle.
It usually indicates that something is defective on one end of the wire.

 

[The_New_Guy]

Thanks peapvp! Very helpful! I have heard of the battry charging circuit being a common problem so that would make sense. Weird that both issues would come up at the same time but maybe that's just my luck.
I will take the alternator out of the system, replace the VAR and runt it for a bit to check function.
I really appreciate the help.
Thanks

 

[Guyfang]

I looked at the Wiring Diagram for 016A. I am not sure if there are differences between the two. I do not have the TM’s for the Bravo unit.
The legend is printed on each diagram to identify components properly.
The alternator charges your batteries. Same as in any car. And VR2 is the regulator for that.

The 016A and 016B are about as different as two 3 KW gen sets can get. The 701 is a 016B in a box. The TM's should be in the TM forum. If not, say something. I am old and may have forgot to upload them.

 

[peapvp]

The 016A and 016B are about as different as two 3 KW gen sets can get. The 701 is a 016B in a box. The TM's should be in the TM forum. If not, say something. I am old and may have forgot to upload them.

Guy,
The test for VR2 is from the 016B TB.
It’s all Kosher. It also states it in the picture.

Peter

 

[The_New_Guy]

Sorry I didn't get the new VR "manual" posted up last nigh like I said I would. But, better late than never.
I really appreciate the feedback.
Thanks!

 

[jas671]

I know that this is an old thread, but, I'll comment anyway.
It is likely that if the battery was connected backwards that this could happen, as it would then be a dead short through VR2. I did this to my Kubota tractor a few years back by connecting a lithium jump start box backwards.

VR2 is likely fried. If you replace that and the burned wiring, some of which is actually part of the VR2 assembly, you should be good to go.

That said, does anyone have a good source for VR2? I have a MEP-016E that has a failed VR2. The VR2 from my parts unit is also bad, and has way too high an output voltage.

 

[Guyfang]

Can you post a picture of the data plate? Because MEP-016E is something new to me. Are you sure its not an MEP-016B?

 

[Guyfang]

If your set is a MEP-016B, then there are several DC volt regulators in ebay.

 

[jas671]

Can you post a picture of the data plate? Because MEP-016E is something new to me. Are you sure its not an MEP-016B?

MEP-016E is the designation for the MEP-016B that has been retrofitted with a Yanmar L100 engine.
Here is a link for manual for doing the conversion: https://media.greenmountaingenerato...2032327/MEP016B-MEP016E-Conversion-Manual.pdf

Here is a data plate from another thread on the MEP-016E here on SS.

 

[Guyfang]

I am corrected! In 20 years active doing power generation and almost 9 years contracting for the Army, I never once saw an E model. The DC volt reg will be the same as the B model. Like I said, several on ebay.

 

[2Pbfeet]

What is 120V 3 phase used for? That's a new one to me.

All the best, 2PbFeet

 

[jas671]

I am corrected! In 20 years active doing power generation and almost 9 years contracting for the Army, I never once saw an E model. The DC volt reg will be the same as the B model. Like I said, several on ebay.

FWWI, my two Yanmar L100 converted units have MEP-016B on the dataplate.

There are many differences, including an electric lift pump that is the same type pump as the aux fuel pump, instead of an engine driven one.

 

[Guyfang]

What is 120V 3 phase used for? That's a new one to me.

All the best, 2PbFeet

Lots of commo vans, repair vans and such. When I was in Hawk, all the commo rigs were 120-3 phase.

 

[Guyfang]

FWWI, my two Yanmar L100 converted units have MEP-016B on the dataplate.

There are many differences, including an electric lift pump that is the same type pump as the aux fuel pump, instead of an engine driven one.

A lot of time, after an upgrade, small things got forgotten. Data plates were on of them. When the upgrades were done by the owning unit, this was very often the case. These kind of upgrades should have been done at the D.S. level, normally. The electric fuel pump was an extra that could be ordered separately.

 

[jas671]

FWWI, my two Yanmar L100 converted units have MEP-016B on the dataplate.

There are many differences, including an electric lift pump that is the same type pump as the aux fuel pump, instead of an engine driven one.

A lot of time, after an upgrade, small things got forgotten. Data plates were on of them. When the upgrades were done by the owning unit, this was very often the case. These kind of upgrades should have been done at the D.S. level, normally. The electric fuel pump was an extra that could be ordered separately.

My two MEP-016E also have MEP-016B on the data plate.