ID wires on a 3Phase motor.

T

trg-s338

Active User
Registered
Joined
Apr 3, 2011
Messages
74
I have a 9 wire three phase motor to be used as an idler for an RPC. There are no labels on the wires, lost or cut off when decomissioned. I have looked extensively on the net how to figure it all out. Seems complicated and confusing. Does anyone have a suggestion for a do it yourselfer? Is there a simple way to figure it? If not, I guess I'll have to take it to a motor shop and pay $80.00. Can I save the money?
 
I'm not aware of a method of identifying the leads. It may be worth the bucks not to burn up a good motor.
 
Take it to the motor shop. They may have the equipment to figure it out. The question was asked on the Leeson site and that was the answer the tech gave as it is impossible to determine the sequence of the coils.
 
Well, just got the motor back from the motor shop. It cost $65.00 to get the wires relabeled but I got to see it run, wired for 240 V 3Phase.
 
Money well spent. Now you know what you have. Is it quiet, are the bearings OK?
 
I'm not sure if the guy at the shop was trying to drum up extra business but he wanted to replace the bearings. While running, however, the motor was smooth and quiet so I'll "let it ride" for a while until it gets loud before I do the bearings.
 
Bronze bushings or bearings? May see a difference once there is loading on the motor but as you say lets see what happens.
 
Bit late I know, but for future reference, this is how you do it (see attached) if you are using a normal three phase supply, and after you have identified the three coils, you connect the motor and one of the coils is the wrong way round, the motor will hum and run slowly. However if you are using a VFD or other form of Electronic artificial three phase system it may be damaged. If you are using a rotary phase converter, or a system using capacitors and a slave motor, that will be ok too. To use a three phase motor on 240v three phase from a VFD it must be connected in Delta. As has been said above, unless you are sure, it's cheaper and safer to consult an expert!!
PHIL.
 
You must log in or register to reply here.
Back
Top