Century Centruian B2748 not turning over

  • Last Post 31 October 2019
Gamera posted this 30 October 2019

I'm hoping you can help me diagnose a problem with my Century B2748 motor. This unit was newly replaced in July of 2018. 1.5 weeks ago it started having trouble "turning over." Sometiems it would start fine, and when it does the motor works brilliantly.

When it fails, the motor hums, overheats and shuts itself off, and often trips the breaker. I hot, oily-smell can be detected. I have confirmed that the impeller is clear of debris and the motor shaft spins freely.

Yesterday I replaced the capacitor that is under the external "hump" on the case. I replaced it with a 30uF 440v single node capacitor. That did not solve the problem, as the motor was still unable to turnover.

I removed the back-cap off the motor to look for start capacitor but there does not appear to be one. I have not yet further dissassembled the motor.

Help! Where else should I look to diagnose? My pool repair company wants to just replace the whole motor, which is compeltely ridiculous.

We experienced several rapid power surges the day the issue starte, which is what is pointing me toward a power issue.


InyoRob posted this 31 October 2019

Since the shaft spins freely and the capacitor is good, my next guess would be a bad phase winding. There is a slight chance it could be a bad thermal overload. The thermal overload can be replaced but if it's the windings, the motor should be replaced.


Thermal overload pictured below.

A.O. Smith UST1102 Thermal Overload Protector - 610806-061

We have a guide on testing the windings. http://www.inyopools.com/HowToPage/how-to-use-a-multimeter-to-test-a-pool-pump-motor-continuity.aspx