MEP 003A - Low Voltage on L1 & l2 when set in 120/240 Volt position

[Bross177]

I have a recently purchased MEP 003A. The genset starts and runs sufficiently, however I can only get 28-30 volts on L1 & L2 when the Reconnection Switch is set in the 120/240 Volt position but 115 Volts from the L3-L0. When the switch is set in the 3Ph position, the voltage from L1-L0, L2-L0 & L3-L0 are all ranging from 114-115 without adjusting the voltage increase switch. The L1-L3 voltage is about 200 at the 3Ph setting, again without adjusting the voltage increase switch. When the Reconnection switch is set at 120 Volt Ph1, the L3-L0 is putting out about 115 Volts. Any ideas why the L1 or L2 are not coming up in the 120/240 position? Continuity through the AC breaker tests OK. I have not attempted to test the Reconnection Switch. looks a little complicated. Is there a testing criteria for that part available?

 

[dangier]

Bross,
My 002's and 003's are set up thus: 120/240 mode, L1 and L3 give you the 240 volts, L1 to L0, and L3 to L0, gives you the 120 volts respectively. I have not run the 120 only and 208 3 phase (although they checked out when tested). Do you have the decal showing the connections? If not, let me know and I will send a picture. I wouldn't put it past someone switching main leads (by accident or otherwise).
David

 

[Triple Jim]

As an aside, the knob on the panel is meant to allow the operator to set the voltage to 120/240. It says "increase" and has an arrow to show which way to turn it. It's not meant to be a "voltage increase switch."

As Dangier said, in the single phase 120/240 setting, L0 to L3 should give you 120v, and L0 to L1 should give you 120v. L2 is not used with that setting, so don't worry about what your meter reads on that lug.

 

[Ray70]

Sounds to me like your reconnection switch is either acting up or is miswired. The TM shows all the jumper connections and where they should be.
I'd try loosening the 1/4" bolts that secure the sections of the switch together, spray some WD-40 between the sections then work the switch knob back and forth a bit then tighten it back up. If it still acts the same consult the TM and check all the wiring connections on the switch. Also, are you switching the selector knob on the control panel to match the reconnection switch setting? Although I can't recall now if that switch being in the wrong position would affect the voltage at the lugs or just the gauge readings.

 

[Triple Jim]

Ray, the front panel meter switch affects only the meter readings, not the output at the lugs.

 

[jamawieb]

Like Triple Jim said, on 240 single phase you should have voltage reading from L0-L1 (120 volts) L0-L3 (120 volts). The knobs on the front panel only affect the gauges, nothing else. Try retesting and then let us know what you find?

 

[Bross177]

Sorry All:
I had some interruptions.
According to the operator's manual, the Voltage Rheostat on the control panel adjusts the voltage output. But that is not what I believe to be my issue. When I switch the Reconnection Switch to the 120/208 3Ph position, L1-L0, L2-L0 and L3-L0 all test close to the expected voltage. When I switch to the 120/240 Ph1, the L3-L0 lugs test close to the desired 120 @ 115 volts; The L1-L0 lugs test around 28 volts and the L1-L3 lugs test around 85 volts.

I did find a discrepancy in the ammeter/voltmeter switch position. I read a table last night that said that switch should be set at Ph 1, L3-L0, L3 for 120/240. I thought that would have been the setting for the 120 volt 1PH. Again, I do not believe that any of that is my problem and agree with Triple Jim, jamawieb.

Ray,
I haven't had a chance to act on your suggestions but intend to do so by the weekend.

Thank you all for your help.

 

[Ray70]

Bross, any news yet? Just wondering if you've made any additional headway?

 

[Bross177]

Hey All:
I just can't thank you guys enough for your comments and advice. Ray, you hit it on the nose. The L1 and L2 wires from the main breaker to the reconnection switch were both connected to the L2 terminal. I moved the L1 wire to the L1 terminal and the generator is now producing 120/240 Volts. It handled the 32 amp load that we put on it with no problem. It also tested correctly for 3 Ph 120/208. The 1 Ph 120 is not producing current on the L3 though and I haven't been able to see what is going on there. We won't have any need for that selection, but I will try to correct the wiring so that it will work like it is suppose to. Anal retentive my wife calls it.

 

[Ray70]

Fantastic, glad you're up and running now.... Might as well fix L3-L0 while you're at it, some day you might need it, plus if you ever decide to sell it you have a machine that works correctly in all configurations. Not anal retentive, It's just taking pride in your work and doing things the right way.

 

[Bross177]

Yea Ray. You're right. You never know when you will need something to work like it is suppose to. My Dad always said "Safe ain't sorry"
thanks again all.