Please help me understand how to wire this 3P, 460V motor that has internal automatic thermal protection. Tracing out what I have been been provided seems to lead to 3 open phases. What does the dwg mean (top upper left) "insulate separately" and what do i do with those three wires? Where is...
I have 4kV vertical motor. From Feb 6, 2019 until "the event" on April 9, 2019, the UMB (spherical roller thrust type) indicated high temperature spikes on numerous occasions. The spikes (+300F) were detected via remote indications and most lasted less than 30 minutes. On April 6, 2019 the...
When conducting a megger test of 4160V switchgear bus (cubicle to cubicle), how much resistance would a CT add to my result?
Man is troubled by what might be called the Dog Wish, a strange and involved compulsion to be as happy and carefree as a dog --- James Thurber
I have a 480v 3 phase induction motor with 5 to 8% phase to phase resistive imbalance. Mangegemnf decided to start the motor without further troubleshooting. Current imbalance is low around 3%. What effects would I see with a resistive imbalance of say 5 to 10%? Should I push for more...
I have a 460V 75HP fan motor (85.9 FLA and 684 LRA) that tripped its feeder breaker on startup. Everything has checked out good. It is possible that this fan was freewheeling backwards when we tried to start its motor. About how many amps could that situation draw? Or is there a calculation -...
I am testing Cutler Hammer C306 bi-metallic TOLs. Should the poles be tested individually or in series?
Man is troubled by what might be called the Dog Wish, a strange and involved compulsion to be as happy and carefree as a dog --- James Thurber
I have an ungrounded 125VDC diesel generator start system that indicates a positive ground via (1) ground detection light illumination on the battery charger and (2)voltage to ground measurement. (+) to grd reads 75.4VDC while (-) to grd reads 56.7VDC.
The criticality of this level of grd on...
