re-wiring my MEP-004a for different voltages, including single phase

[millertools]

Sewerzuk looking forward to the Mep006 vid did two of mine both worked fine for two or so hour under some load. Shut them down to check fluids re started and one has no voltage and the other has voltage but over volt light is on. The one that has no voltage looks like it burned up the 1.5 k resister in the Dc Relay Assy
and the other looks like it got very hot not sure what went wrong.Think i need to move some little wires on the board.

Josh

 

[sewerzuk]

Think i need to move some little wires on the board.

Josh

YES...this is critical, or you are supplying improper voltage to some components in the exciter...though the generator does produce single phase 120/240 if you only do the zigzag mod, you will certainly stress/damage components if the control circuitry isn't re-wired. I ran my last conversion at over 100% load for several hours with no problems (will show this on the video). The person who owns the -006 used it to supply some equipment for a band, vendor tents, etc. at about 50kw for over a week with no problems, so I KNOW the conversion works.

As far as the overvoltage light, I have found that the overvoltage relay trips sometimes during the field flash after the conversion...the solution is simply to turn down the voltage rheostat during startup and then adjust it back to normal operating voltage. You should still be able to clear the overvoltage light with the test/reset light.

 

[smurph]

As far as the overvoltage light, I have found that the overvoltage relay trips sometimes during the field flash after the conversion...the solution is simply to turn down the voltage rheostat during startup and then adjust it back to normal operating voltage. You should still be able to clear the overvoltage light with the test/reset light.

I saw this too. On my particular MEP005, when I close the air intake doors after running it, the doors will force the throttle closed. So every time I start the genset I have to open the air intake doors, adjust the throttle to about halfway (just guessing at the eventual speed), and start the engine. If my throttle position was too high (even with the voltage know turned down), I will get the over volt during the field flash. Starting the genset at or below 60 Hz with the voltage adjust fully counter clockwise is the cure. Marking the throttle with a "start position" may be the trick.

I have not installed the 40 ohm resistors across the CT terminals yet. Installing them may help the over voltage on startup. We shall see...

Steve

 

[Buzz254]

ALLCON:
Just wanted to let you all know the zig-zag arrangement for the MEP-016b is explained in THIS thread: http://www.steelsoldiers.com/showth...ral-for-016B&p=1226621&highlight=#post1226621

Cheers.

 

[captain]

How bad is it to use 35ohm resistors? I bought them in late 2012. I was sure I got them through a link in this thread but I can no longer find it. Should I dump them and buy some 38+ ohm resistors?

Thanks

 

[sewerzuk]

How bad is it to use 35ohm resistors? I bought them in late 2012. I was sure I got them through a link in this thread but I can no longer find it. Should I dump them and buy some 38+ ohm resistors?

Thanks

35 ohm is just fine; it will get you VERY close, well within meter tolerances. 38 ohm is the "perfect" size; but for real-life purposes, 35 ohm is just as good. You would never know any difference...

 

[1800 Diesel]

Thank you for the response. I look forward to seeing the video so I can convert mine over.

Out of curiosity, I have to ask: What is your application in which a 60KW unit is needed in single phase mode?

I plan to set up either an MEP-004A or maybe an 005A unit whenever I get my large shop built, but plan to leave the unit 3-phase so I can install some 3-phase equipment. Haven't done the load calcs yet but expect the 15KW model will be plenty for what I'll be running (simultaneously).

Kevin

 

[1800 Diesel]

I saw this too. On my particular MEP005, when I close the air intake doors after running it, the doors will force the throttle closed. So every time I start the genset I have to open the air intake doors, adjust the throttle to about halfway (just guessing at the eventual speed), and start the engine. If my throttle position was too high (even with the voltage know turned down), I will get the over volt during the field flash. Starting the genset at or below 60 Hz with the voltage adjust fully counter clockwise is the cure. Marking the throttle with a "start position" may be the trick.

I have not installed the 40 ohm resistors across the CT terminals yet. Installing them may help the over voltage on startup. We shall see...

Steve

Steve,

On the MEP4s I've been setting up, I apply a marks-a-lot (or thick point sharpie) line on the throttle control shaft once the unit's speed is set for 60-hz output. This provides a quick means to set the unit for a cold-start throttle position. You will still need to make minor adjustments up to 61-62hz depending on actual load, but the mark on the shaft provides a baseline setting for the initial throttle position right after the doors are open & latched for running.

Kevin

 

[captain]

Thanks for the info guys. I'm going to do mine this weekend when the weather gets out of the teens. One more question. For the jumper wire. Im guessing that 3/8" terminal lugs will do? Any ideas on what a good length of cable would be? I think I am going to be lazy and buy a ready made battery cable for this one.

Thanks

 

[leedawg]

Thanks for the info guys. I'm going to do mine this weekend when the weather gets out of the teens. One more question. For the jumper wire. Im guessing that 3/8" terminal lugs will do? Any ideas on what a good length of cable would be? I think I am going to be lazy and buy a ready made battery cable for this one.

Thanks

Thats what i did for mine. 12 inches is more than enough cable... Good luck.

 

[rdspal88]

Sewerzuk, I too am awaiting the MEP-006A. I have completed the triple to single phase converison. I cranked up the unit but found that none of the generator gauges work so I simply shut it off fearing I may be doing some damage to the unit. So I am excited to learn you are about to send out a video on the unit...hope it explains where to move the secondary wires

 

[wanderingwillys]

I cranked up the unit but found that none of the generator gauges work so I simply shut it off fearing I may be doing some damage to the unit.

Did you try holding the start switch up for 10 to 20 seconds? - should energize the field and get the generator to start producing voltage...

 

[sewerzuk]

Sewerzuk, I too am awaiting the MEP-006A. I have completed the triple to single phase converison. I cranked up the unit but found that none of the generator gauges work so I simply shut it off fearing I may be doing some damage to the unit. So I am excited to learn you are about to send out a video on the unit...hope it explains where to move the secondary wires

Unfortunately, I pulled up my video footage from the last conversion and it didn't turn out.
Not trying to withhold info at all, but I honestly can't recall exactly which leads were moved. There were just 2 of them from one terminal, but I didn't write it down and must have neglected to hit the record button during that step. I can look at the schematics and tell you which ones I think I moved, but I'm a bet hesitant to do that without being there to watch and listen to the set during field flash...
Basic idea is this: When you cut the bus bar, you turn the newly isolated terminal from a neutral into something "floating." Any leads that relied on this terminal for their neutral need to be moved over to one of the 3 other neutral terminals. It isn't too difficult to figure out...but I hate to give instructions without another set to verify it on. I've done a few -006's now...why I never wrote down wire movements is beyond me. Kind of embarrassing, actually.
The conversion that I took a video of was a "get this done quickly" kind of project for a friend of mine...so it was in and out of my shop in a day and I don't have access to that set anymore. It is in vancouver, so if I get the chance to drop by there sometime I will...and I'll pull the reconnection board to verify lead movements.

 

[rdspal88]

Sewerzuk thanks for your reply. With the weather turning pretty nice now I believe the threat of commercial power outage is remote. I can wait, there is nothing really pressuring me (except desire to get it fixed) to get this unit back up.
With that said...you stated that you moved "2 of them from one terminal..." I looked on my schematics and found that T12 and T9 are the only terminals with two secondary leads.
T12 has X12EG16N(it appears to run to the control cubical?) and X12P16N (exciter)
T9 has X96P16C (it appears to run to the control cubical?) and X9J16C (exciter)
Is this any help???

 

[rdspal88]

No I didn't hold the start switch up but will do so when I figure out how to re-wire the guages. As I have read in other places once I cut the bar between T11 and T12 the guages stop working until some secondary leads are moved around then they typically will start working again. Prior to cutting the bust bar they were doing fine but once I performed surgery they stopped working. Sewerzuk has performed this on a 006A unit so I am pestering him about how he did the reconnects, I trust he will provide me some guidance in the near future. The unit is generating (according to my multi-meter) but would like to have a real time read out if/when I put it in service around the farm...I would hate to blow-up something...My Wife may get a little mad?!?

 

[sewerzuk]

Sewerzuk thanks for your reply. With the weather turning pretty nice now I believe the threat of commercial power outage is remote. I can wait, there is nothing really pressuring me (except desire to get it fixed) to get this unit back up.
With that said...you stated that you moved "2 of them from one terminal..." I looked on my schematics and found that T12 and T9 are the only terminals with two secondary leads.
T12 has X12EG16N(it appears to run to the control cubical?) and X12P16N (exciter)
T9 has X96P16C (it appears to run to the control cubical?) and X9J16C (exciter)
Is this any help???

I distinctly remember moving leads off of T12, but I didn't make a note of it since I thought it was on the video!

Proceed at your own risk, but here's what I would do:
move X12EG16N from T12 to one of the adjacent "neutral" posts. Leave X12P16N in place for now.
Fire up the set, but be ready to shut it down right away if you hear/smell/see anything strange...

I suspect that is enough to create power and working meters. If you notice anything strange about the operation, I'll spend some more time looking at the schematics to re-trace my steps from the last conversion...

 

[rdspal88]

move X12EG16N from T12 to one of the adjacent "neutral" posts. Leave X12P16N in place for now.

I moved X12EG16N to T11 and cranked up the unit...still no guages. The unit operated fine no wierd sound/smoke/etc.

 

[sewerzuk]

You didn't notice any deflection, even while holding the start switch up in start?

The next step would be to move X12P16N from T12 to one of the adjacent posts, then do the cautious startup...

 

[PARKERJOE]

(Sewerzuk)
I recently purchased a 004a, got pretty lucky in only replacing a starter solenoid and fresh set of batteries. I was going to perform the single phase adjustments today, and when i removed the TB 6 plate, i found no buss bar connecting terminals 13 - 10/11/12. put the plate back on and ran the unit. I checked voltage at L1/L2/L3 and all are putting out 118 +/- Volt meter on unit shows area of 230 +/-. (i can increase and decrease). My question is could this unit have already been set up to run single phase?

(There is no jumper wire installed under the TB 6 plate)

 

[sewerzuk]

(Sewerzuk)
I recently purchased a 004a, got pretty lucky in only replacing a starter solenoid and fresh set of batteries. I was going to perform the single phase adjustments today, and when i removed the TB 6 plate, i found no buss bar connecting terminals 13 - 10/11/12. put the plate back on and ran the unit. I checked voltage at L1/L2/L3 and all are putting out 118 +/- Volt meter on unit shows area of 230 +/-. (i can increase and decrease). My question is could this unit have already been set up to run single phase?

(There is no jumper wire installed under the TB 6 plate)

It is most likely still configured for 120/208v three phase.
The buss bar is probably riveted to the underside of the reconnection board (you'll need to remove the reconnection plate, and then remove the 4 stand-offs that hold the bottom section down, then pull/twist it so you can see the bottom). I've seen them on both the top and the bottom, but as time goes on I'd say there is a higher percentage of them on the bottom. More difficult to get to, but you can just cut it with a dremel in place. Tight quarters, but not impossible.