induction motor connections


Thread Starter


Sir, I am a student of Thiagarajar College of Engineering, Madurai, Tamil Nadu, INDIA. I am undergoing Post Graduate Programme in Power System Engineering in the Electrical and Electronics Engineering Department of the college.I wish to get the following doubt clarified : Please suggest possible way(s) of determining whether a given three phase induction motor is connected in star or delta. The constraints being, the motor end connections are made prior, physical veification of which is not possible. and only three terminals of the motor are available externally for supply connections. No other details as regards the number of turns per phase or diameter of the conductor is possible. Please suggest also relevant books, technical literature or web sites from where detailed information regarding this may be obtained. If such a method is not available as of now, please do convey the same. My e-mail ID is : [email protected] Awaiting your response, With regards, prakash.v

lee eng lock

i guess the simplest way might be to measure the power factor of the motor. in delta it should be normal, in the range common for the number of poles/hp, while in star it would be pretty low. rgds leelock
Commercial motors are built neither star or delta. If you see 6 wires then you have the choice to feed externaly star or delta. If you see only 3 wires out of your motor, then it is internally connected delta.
Although quite late, this is my reply to the thread initiated in May 2001:

Does the originator have an answer to the question asking how to determine if a motor is delta or wye connected?

If not, and assuming that the original question concerned dual-voltage machines, then contact me!

Phil Corso, PE
(Boca Raton, FL)