Dover DMC1/M Keeps popping overload ?greenspun.com : LUSENET : Elevator Problem Discussion : One Thread
elevator keeps popping overload. Put amp probe on line in. It draws 250amps buy the time it switches to delta an popps the overload. tried new motor. 20hp 460v 3phase. nothing changed. took pump apart changed bearing still poppes overload.
-- Kenneth R Clarke (firstname.lastname@example.org), February 27, 2001
Once encountered something like this , although it wasn't a DMC.
Turned out the insulator block or arc shield had developed a "track" and it would short between phases at high current levels. You had to put your ohmeter on "x100,000" to see the "short". New starter solved the problem.
Like yourself, replaced the motor first, since when it was connected, there appeared to be a defect in the windings, which was really the bad insulator showing up.
-- John Brannon (akaelevman@AOL.com), February 27, 2001.
John thanks for your responce. I failed to mention we did change the starter out . still popping overload.
-- Kenneth R Clarke (email@example.com), February 27, 2001.
Ken - it may be that you are attempting to lift the car while the motor is still connected "WYE". As the motor has only 56% of line voltage impressed at this point, it has insufficient torque to lift any load.
First, disable your "UP" solenoids and make sure the car will stand still without any creepage at the lower floor with the motor running and with no load and the oil at minimum temperature.
If it moves, open the low pressure adjustment until it stands still, then two more turns.
Also, make sure that the "UP" solenoid is not energized while the motor is connected "WYE".
Best of Luck - John B.
-- John Brannon (akaelevman@AOL.com), February 28, 2001.
is it submerged ? if not take belts off pump had this problem before the screws are worn and the pump is binding
-- gip (firstname.lastname@example.org), March 11, 2001.