Customer Testimonials
Quality Industrial Service
5 star review 5 star review 5 star review 5 star review 5 star review
Quality Industrial Service
"Thanks for the prompt service and the encoder you sent works great, we are back up and running! For your efforts, we are sending you 2 encoders and a servo motor to be repaired. Kudos to Repair Zone!"

Wayne Bentzen

See More Testimonials › 
Home ›  Learning Center ›  Tech Notes ›  Detail


SurgeTesting a Servo Motor

SurgeTesting a Servo Motor

By Jade York
             When a servo motor comes in for repair, one of the most important tests  is the surge test, which tests the windings to make sure there is not a break or short  in it. 
           A surge test is an impulse test used to determine the diaelectric strength of the interturn insulation turn to turn, phase to phase, in a coil or winding.  It displays up 2 phases at a time so you can compare them.
  This is done by using the surge tester and testing all 3 phases of the motor.  While under electrical load, we monitor the wave-form patterns and look for a balanced wave-form on each phase which tells us that it is good.  If the phase is bad, the wave-form is unbalanced and can contain a straight line or an erratic look to it.  In this case, the phase is good.

Servo motor repair - Surge testing
Servo Motor repair - Surge testing
Servo motor repair - Surge Testing

   A comparison of the 2 wave-forms from 2 phases during the surge-test, shorts in one winding will cause a separation in the 2 wave-forms.  There are 3 phase combinations to compare.  If shorts are present, that stator will need to be rewound. 
             In that case, we would send it to our winding department where it will take 2-3 days for completion.  Before we reassemble the motor, a final surge-test is done to complete the repair. If it passes, it is then assembled and a run test follows.  

For more information on servo repair.  Repair Zone has repaired over 12,000 servo motors.

Return to All Tech Notes link
Payment Methods Accepted
We accept Visa We accept Mastercard We accept American Express
We accept Discover We accept eCheck We accept PayPal