Mep 002 question. What is the switch on the front of the control panel 1 or 3 phase

[Philratcliffe]

I am trying to find out what the purpose of the switch in the front of the control panel is for that has several 3 phase positions and two 1 phase positions. I’m assuming it needs to be in the correct position for all the gauges to work properly? Is that it’s purpose??
I’ve never had issue with my 002s until recently I switched one of my sets to three phase with the big knob on the side box to test the three phase operation but was unable to switch it back. The switch is stuck. I broke the knob twisting on it, i even tried vice grips but it wouldn’t move. My friend took it apart and we got it back I to single phase position. When I ran the unit after the repair the planta would lose 220v. It still had 120 from the fist lug to neutral and from the third lug to nuetral but no 220v. Thanks in advance for any info
We are going to take the switch apart in the am and see if some of the contacts aren’t loose. It’s weird as it doesnt trip the breaker it just stops making 220

 

[Chainbreaker]

I am trying to find out what the purpose of the switch in the front of the control panel is for that has several 3 phase positions and two 1 phase positions. I’m assuming it needs to be in the correct position for all the gauges to work properly? Is that it’s purpose??
I’ve never had issue with my 002s until recently I switched one of my sets to three phase with the big knob on the side box to test the three phase operation but was unable to switch it back. The switch is stuck. I broke the knob twisting on it, i even tried vice grips but it wouldn’t move. My friend took it apart and we got it back I to single phase position. When I ran the unit after the repair the planta would lose 220v. It still had 120 from the fist lug to neutral and from the third lug to nuetral but no 220v. Thanks in advance for any info
We are going to take the switch apart in the am and see if some of the contacts aren’t loose. It’s weird as it doesnt trip the breaker it just stops making 220

Yes, the switch you are talking about is used so the Voltage can be read off specific output lugs displaying voltage on the gauges in various 3 phase or single phase configurations. So yes, its just telling the gauges to read from those Lugs you are switched to (L1...L3...etc) and can be switched while the unit is running to check voltages. Has nothing to do with how the output is configured, that is accomplished by the "Reconnection Switch". There was some member here a few months ago who did a very nice "color coded diagram" explaining the switch positions but I cannot find it.

Most people here that have ever dared to take the Reconnection Switch apart recommend to never do that as its a bear to put back together. The recommendation is to just loosen the screws/nuts a tad bit that hold it together. That will free up a stuck switch and its recommended that contact cleaner is sprayed in between the wafers while it is loose and exercise the switch back and forth.

 

[Philratcliffe]

Yes, the switch you are talking about is used so the Voltage can be read off specific output lugs displaying voltage on the gauges in various 3 phase or single phase configurations. So yes, its just telling the gauges to read from those Lugs you are switched to (L1...L3...etc) and can be switched while the unit is running to check voltages. Has nothing to do with how the output is configured, that is accomplished by the "Reconnection Switch". There was some member here a few months ago who did a very nice "color coded diagram" explaining the switch positions but I cannot find it.

Most people here that have ever dared to take the Reconnection Switch apart recommend to never do that as its a bear to put back together. The recommendation is to just loosen the screws/nuts a tad bit that hold it together. That will free up a stuck switch and its recommended that contact cleaner is sprayed in between the wafers while it is loose and exercise the switch back and forth.

Thanks so much for for the info I’m going to try to find that thread it would be a godsend about now. I have three 002s and two have an issue with this switch.
I am trying to buy a pair of output control boxes now. Thx again.

 

[dependable]

From my experience, it is worthwhile to check connections to main voltage selector switch on the 002. They vibrate a lot due to motor configuration and often work fasteners loose. Have even seen a couple of the twelve main leads from gen head loose on that switch. That will screw up up output every time.

You do not have to take switch apart to turn when stuck. Unless you have infinite patience, likely never get it together again. Just loosen the nuts on the bolts that hold it together a little bit, and turn to desired voltage configuration. Some light spray lube also helps. Then tighten up again.

I've noticed that the phase selector switch often seems to have a memory, probably run in 3 phase a lot. So if you do work it around to 120/240 single phase, don't switch it around unless you need to.

 

[Chainbreaker]

Thanks so much for for the info I’m going to try to find that thread it would be a godsend about now. I have three 002s and two have an issue with this switch.
I am trying to buy a pair of output control boxes now. Thx again.

Found the color coded picture (it wasn't easy to find) and text that explains the switch settings. Look at Post # 28 in THIS THREAD.

Hope this helps.

 

[Ray70]

If you are still having problems dropping the 240V, do as outlined above, loosen up the long rods holding the selector switch sections together, get between the sections and into the openings where the connection tabs poke out of the switch and spray it good with contact cleaner, then work the switch back and forth a bit. If the switch happens to get stuck again, don't force the knob, rather, try jiggling back and forth, they usually free up with the bolts loosened. You can also clean the AM/VM switch, but if you are loosing power, it's not the AM/VM switch.
Also, am I reading correctly that you have 120V from L1-L0 and 120V L3-L0 but you don't have 240V from L1-L3? That seems odd...

 

[Guyfang]

If you took this switch out to fool with it, and put it back in the set, the first thing I would do is check wire for wire to see if you hooked it up wrong. In the -34 TM are Schmatices. There are two different type switches. So you have to look and see what you have.

 

[Philratcliffe]

If you are still having problems dropping the 240V, do as outlined above, loosen up the long rods holding the selector switch sections together, get between the sections and into the openings where the connection tabs poke out of the switch and spray it good with contact cleaner, then work the switch back and forth a bit. If the switch happens to get stuck again, don't force the knob, rather, try jiggling back and forth, they usually free up with the bolts loosened. You can also clean the AM/VM switch, but if you are loosing power, it's not the AM/VM switch.
Also, am I reading correctly that you have 120V from L1-L0 and 120V L3-L0 but you don't have 240V from L1-L3? That seems odd...

That’s exactly what’s happening. If I reset the breaker I have 240 again. Then it drops out. We have had the switch apart several times and took a second switch apart to map all the clicking positions of the first to confirm it was assembled correctly. The breaker isn’t tripping either. I just loose 240. I bought two gov refurb switch boxes complete so will install one as soon as they arrive. I’d still like to figure out what’s causing this problem! Thanks

 

[Philratcliffe]

If you took this switch out to fool with it, and put it back in the set, the first thing I would do is check wire for wire to see if you hooked it up wrong. In the -34 TM are Schmatices. There are two different type switches. So you have to look and see what you have.

Are you saying different year mep 002s have different switches in them? Thanks

 

[Guyfang]

Are you saying different year mep 002s have different switches in them? Thanks

Yes. Take a look at the manuals. There are two different switches. The TM explains all about them. There are mostly similar wire connections, but a few are somewhat different. Its not rocket science, so read the book. -34 manual explains it all. Take your time, look at each connection and do not rely on tags someone may have hook to the wires. LOOK AT every wire. LOOK AT every terminal. Make sure to double check, if not triple check each wire and terminal.

Also. Your refurbished boxes? Are they 002A boxes? Or 003A boxes`Or maybe a MEP-112A? Make a difference.