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Topic starter
27/04/2023 11:59 pm
Circa 71, hoist motor had let the smoke out of it. Got a rebuilt one from the good folks in Florida. It runs very fast now, and it is tripping the 3p and or burning the 5/6 contact in the NL relay. Both of these are right in line with the Motor Armature.
Any ideas?
28/04/2023 3:46 am
Hi,
sry have no idea what this is for a motor, but an idea I have anyway:
star-delta connection motor swapped
28/04/2023 5:57 am
Sounds like your motor shunt fields might be too weak. That would explain the higher speed and armature current. If your shunt fields weakened it doesn't induce as much counter voltage into the armature windings, allowing more current to flow through the armature which makes more torque which equals it speeding up as well.
Topic starter
28/04/2023 6:57 am
Yes, some one suggested that the motor field voltage may be too weak.
Topic starter
28/04/2023 10:09 pm
Do not think it is motor field voltage. We are over speeding in the inspection mode, and getting full voltage to the field on inspect.
30/04/2023 9:01 pm
Is this motor compound wound? If it is, are the series and shunt fields hooked up cumulative or differential?
Whats the armature voltage compared to nameplate full speed armature voltage? Is the motor simply getting more voltage than you want it to for inspection speed? Maybe the wrong generator field relays pulling in, or somehow some resistors in the controller are shorted?
Topic starter
02/05/2023 4:57 pm
I will try to post what we find, got another tech coming in.