Testing Squirrel Cage Rotor

Can you repair your large squirrel cage rotor or does it need to be outsourced?

Download Your Free Industrial Rotor Testing Guide

This is a must-read for electric motor repair personnel dealing with larger motors that need to determine the integrity of a squirrel-cage rotor and if it needs to be repaired in-house or outsourced.

In this timeless resource article, you will learn methods for how to determine broken and lose bars, voids in endings, cracks, vibration, overheating, and much much more….

Open Rotor Bars
  • Most common reasons for squirrel cage rotor failure
  • Learn methods for testing a squirrel cage rotor which has failed or is near failure
  • How an induction rotor works
  • The problems broken rotor bars can create
  • 19 colored pictures and graphs
  • And much much more

Disassemble Motor Rotor Testing Methods

Visual inspection of rotor failure:

  • Balancing issues
  • Cracked endrings
  • Melted aluminum or copper
  • Shifted laminations
  • Casting flaws in endrings and bars
  • Localized burnt spots
  • Open bars
  • And more
Open Rotor Bars

Testings methods

  • Growler testing for open bars
  • Coreloss testing for iron integrity
  • High current excitation testing for open bars
  • Spectrum analysis for vibration testing
  • Tap testing for loose bars
  • Dye penetration test for cracks
  • Temperature paint testing for hot spots
  • Ultrasonic testing for voids in endrings and cracks in the shaft
  • Low resistance ohmmeter testing for broken bars
  • High current low voltage transformer testing
  • Thermal imaging

Download Your Free Industrial Rotor Testing Guide

Assembled Motor Rotor Testing Methods

Open Rotor Bars
  • Single-phase testing for open bars
  • Two ammeter comparison testing for open bars
  • Stroboscope testing for speed issues
  • Vibration analysis
  • Motor current signature analysis for open bars
  • Stray flux testing for open bars
Electrical Apparatus offers a number of custom services built to suit your repair needs