P&H crane motor - extra leads
P&H crane motor - extra leads
(OP)
Just got a replacement bridge motor - HEWH286, 15 H.P.,
1140 RPM, 460v, mfg. no. 286M1076 (3-phase/wound rotor)
for a P&H 35 ton crane. This motor has 4 extra, unmarked
leads, approx. AWG18. Can anyone identify them?
Wouldn't be a problem, but the motor started heating
immediately upon start after installation, so we would
like to know what the leads are - to eliminate them as
a problem, at least.
<als>
1140 RPM, 460v, mfg. no. 286M1076 (3-phase/wound rotor)
for a P&H 35 ton crane. This motor has 4 extra, unmarked
leads, approx. AWG18. Can anyone identify them?
Wouldn't be a problem, but the motor started heating
immediately upon start after installation, so we would
like to know what the leads are - to eliminate them as
a problem, at least.
<als>





RE: P&H crane motor - extra leads
If there is no brake I would suggest checking the contactors for open or welded contacts. When a motor fails, it occasionally damages the contactor. Also when a contactor fails it occasionally damages the motor.
yours
RE: P&H crane motor - extra leads
Crane bridge has two motors (one on each end) controlled
by a single contactor. Other motor works fine.
(This is a 5-speed arrangement, using stepped rotor
resistance).
<als>
RE: P&H crane motor - extra leads
If there is a broken connection in the primary wiring the motor can be single phasing. With a two motor drive it can start with mechanical help from the other motor but will overheat. Is the motor pulling its share of load, or overdriving?
yours
RE: P&H crane motor - extra leads
RE: P&H crane motor - extra leads
Mike Halloran
Pembroke Pines, FL, USA
RE: P&H crane motor - extra leads
Been there, done that on a large bridge crane drive control retrofit! Installing contractor tested the motors on the ground using the same VFD, but when installed on the bridge, the two different VFDs had apparently been programmed for opposite rotation in the previous installation because someone was too lazy to swap leads. We couldn't figure out what the heck was wrong for hours!
Eng-Tips: Help for your job, not for your homework Read FAQ731-376
RE: P&H crane motor - extra leads
... okay, I'm really learning more about now _not_ to...
Mike Halloran
Pembroke Pines, FL, USA