MEP-002a Voltage Issue

[mtfleming]

I have a MEP-002a and had it checked out at Delk's. They put it on a load bank and could find no problems with it. When using this generator it goes (240V setting) first into a SMA Smartformer which drops the voltage to 120v and then to a charge controller to charge batteries. When used in this way the voltage will drop to about 200V and is no longer adjustable. I also have a Ridgid generator that I use. The voltage drops a little with it but not so much. Is the military generator made differently so that it not compatible with the Smartformer? Can I bypass the Smartformer and run the MEP-002a at 120V? I was advised at one point not to run it at the 120V setting.

 

[Light in the Dark]

Well using a step down doesnt make any sense here, as you can absolutely configure an 002A to output 120V single. Do you have the manuals for this set?

 

[Light in the Dark]

If not, start here: https://www.steelsoldiers.com/showthread.php?155935-All-the-TM-s-you-need-to-work-on-the-MEP-002A

Who told you not to run it at 120? Was it possible this person didn't know the set was adjustable output, so they said this thinking you were going to be running an unbalanced load (only one leg of 240V)?

 

[jamawieb]

Yeah, switch it to 120v single phase and bypass the smartformer.

 

[mtfleming]

William at Delk's said it was not a good idea to run the gen at 120V. He may have been thinking about the possible fault condition. The instructions say run a jumper from LO to #6 in section G. I am unable to find out where this is. As a side note, William passed away near Christmas. He was Delk's main generator guy.

 

[DieselAddict]

I'd be curious why it was stated that its not a good idea to run in 120v configuration. I could see an issue with making sure you could handle the fault current but otherwise its the second best choice from an efficiency choice. Three phase being the best and 240v split phase being the worst.

 

[mtfleming]

What would I connect the jumper to? The instructions say from LO to #6 in section G, which I can't find .

 

[Guyfang]

What TM, what page.

 

[mtfleming]

TM 5-6115-584-12. Change 6 page 2-3 figure 2-2 Reconnection Switch

 

[Guyfang]

If you look at the schematic you will see between terminals LO and #6, on the S6 switch, a jumper. On some early versions of the schematic this wire was not there. That's why the warning was added. Depending on what version of the schematic you are looking at, the jumper may, or may not have the famous "fickle finger of fate" symbol to indicate that this is a change to the manual/schematic. You are using a TM that only has change 6, you should download the TM from here in the forum, it has change 11 as the last change.

 

[jamawieb]

Or William meant its not good to run the set on a single leg when it is set to 240volts single phase?

 

[mtfleming]

thanks

 

[mtfleming]

Not sure why

 

[Chainbreaker]

Not sure why

As Jamawieb points out, it is bad to only load one 120V leg when in 240V mode. It creates a imbalance or differential that can cause gen head windings to overheat. That is why those of us running our house in 240V single phase try to pay attention to various loads and balance our 120V household loads as evenly as possible on each 120V leg (I seem to recall that they should typically be within 20% of each other while on generator power). However, 240V loads such as clothes dryer, oven, etc. are naturally balanced because they use both 120V legs for the 240V circuit. If the electrician who initially ran the wiring to one's breaker box did his job properly most of the circuits should be fairly evenly distributed between circuit A or B. I realize your not using for household purposes but that is the explanation of potentially overloading a 120V leg while in 240V single phase as I understand it.

I hope that is what you were questioning. If not, please elaborate.