Only took a breif look today...
The company that ran the 2 1/2" conduit 195' w/ 3 - 4/0 was there yesterday. (Big Union outfit) (Voltage drop got ruled out. As it was minimal.) Owner wants every opinion he can get, before they dump the money for the third starter. Which is why they asked me to stop by.... Cause the original installer, and Elevator rep had it out, I'll say why in a moment, anyway I'm going to limit myself between them two.
The facts as they stand now... As I know.
Soft start (1/2 and 1/2) 45 HP 6 pole motor on 208. In-rush is really high, really long, getting progresively worse, went OL on my clamp-on today and operating current seems to vary pole to pole. (600A Was just what I had with me today.) Running amperage also varies, and pole to pole. 160-220A
Now here's where opinions differ, and get down right stupid, between installer and Elevator rep yesterday.
Electricians opinon: (I at this point partialy agree without 3-phase monitoring) Is that the 6 pole motor is mis-wired, or motor is failing on one or more poles. As I have smelled the distinctive stench of burt motor in the elevator before, and brought this to the owners attention, I can agree. Especially after getting such odd readings today, however minimal. The other Electrician blames Elevator.
Elevator guys opinion: which I heard from the other electrician, and owner today. Lack of "triplexing" feed conductors. OK good point, but no-one does it, or should I say almost no-one. Doubt it would be the cause of this, or to this degree. His suggestion, replace the feed. Or this, which sent the Electrician into fits of rage, and myself into fits of laughter, was to "break the conduit open at the couplings and fill it with expanding foam". I almost keeled over when the owner told me, and later talked to the electricain who was still enraged from yesterday.
My suggestion: Check motor wiring for crossed poles, and power monitoring to get clearer picture of what is actually happening, The megger on the feed it's a bad idea either, but hard to know if any degradation of insulation is from install or current, as this thing is about to give up the ghost soon. Let met re-define "rattle"... This feed in the basement can be heard up to the second floor. It's an un-godly sound that says emminant failure. Some more information is that a UPS is failing, lighting, and ballasts are dieing everywhere which makes me thing harmonics too.
I'll keep you all posted, on what happens, but I'm gonna step back and let these two battle it out some more.
