Good morning fellow elevator techs. Before you jump to conclusions about me burning out 4 hydro motors on an MCE (HMC-1000) read what I tested, replaced and checked and see if you have any ideas. I don’t think I am a total [censored] but if someone can prove me wrong, I’ll be happy to admit it.



duplex 4 stop MCE controllers with Wye/start delta run relays
480VAC/3ph
40HP high voltage motor (wired correctly)
200-amp breaker in the electrical room
both controllers are fed from the same buss bars in the main power breaker room
100 fuses in the disconnect switch


1st motor:
Went to the job found 200-amp circuit breaker tripped in the electrical room (didn’t blow fuses or trip my overload) then found the original motor shorted
replaced the motor, checked main line relays, voltage, wiring amped motor. all checked good. Thought the motor just went bad due to age since nothing was found to be bad. Checked the motor start/run relays and they were binding (Aromart contactor but were not getting stuck in or binding at all)

2nd motor:
Went to the job same thing (200 amp breaker tripped) checked overload, fuses and tested motor, found motor burnt out. I was told that the only thing causing this would be the start/run relay hanging up. So, we replaced the motor, overload start and run relay. Wired up (triple checked the wiring) and its good. Amped the motor after the install inrush was like 135amps +-10% from line to line running amps was 35amps +-5%.

3rd motor:
Went to the job same thing (200-amp breaker tripped) checked overload, fuses and tested motor. motor shorted internally (winding shorted together). I start thinking my breaker is bad (since its always tripping). I switch the breakers in the electrical room. Installed an overload when L1,L2,L3 come into the controller and set low (like 30amps) in addition to the motor overload that still hasn’t tripped. Megged the wires from the electrical room to the disconnect switch, from the disconnect switch to the controller, from the controller to the motor. Everything reads 600+MEG ohms ~ohms. Hook up the new motor myself (it was previously wired by another mechanic but it was wired correctly). I call MCE to see what they think and they tell me the problem is not from the controller. Hooked up a camera system to watch the elevator run and left the car running. 1 week later we get the call the car is shut down. AGAIN, level at the floor breaker is tripped

4th motor:

Boss sends a team back with a 50hp motor (motor shop told him the lead ins are breaking due to amps/single phasing) I tell him the 50hp can hurt us because of inrush current (but he’s the boss) not to mention the contacts aren’t sized for a 50HP motor.
Call up MCE get a soft start (this supposed to help see the issue) . Go to the job install everything, set the settings of the soft start to below name tag. Installed the New MCE relay board that came with the soft start and 4 days later the car shuts down. Level at the 1st floor and the camera shows the car sitting there with custom loading basic house hold items in the elevator. Customer Goes to their car to get more, the doors close and the elevator relevels, the elevator levels up and boom its off.

Here we are today (2/2019)
I see that the windings that are shorting are the ones getting power straight from L1L2L3 jumped to the fault contact. ( ill attach a pg of the print) So the windings coming out the t456 of the fault contact is shorting. This is the same case as the start/run relays we swapped out. Almost like the motor is cooking while sitting there not running (but fault contactor is fired all the time as it should be). I am not an electrical engineer but I can only see it being one of two things (and I know the one is a reach).

1 Wiring from the electrical room to the controller (including the disconnect) is intermittently grounding or shorting. I plan on switching the controller feeds and hope the issue switched from car B to car A. The Meg test I did earlier should of picked up on any insolation issues within the wires and disconnect switch.
2 Small transformer on the controller. Off on L1L2 there is a transformer that takes the 480 and drops it to 208 and 120. If somehow this is breaking down and shorting internally, I thought maybe it’s putting high voltage. IDK it’s a reach but I am completely out of ideas on this.

Now 5th motor is ordered and soon I’ll go with a lighter and can off gas and just burn it myself

If you have any ideas or insight please let me know.