Iris Power MDSP3

Current Signature Analysis for Squirrel Cage Induction Motors

The MDSP3 detects rotor cage winding faults including broken rotor bars, cracked shorting rings and unequal air gaps.

Works with These Assets


  • Advanced Algorithms:  to accurately predict the operating slip from the measured current. The slip calculations can also be done at different loads.
  • Simplicity:  Can detect cage winding faults and eccentricity with the use of a single clamp-on current sensor connectedto the secondary side of 50 or 60 Hz motor current transformer; or around one of the phase leads.
  • Reliability:  Reduces the risk of false indications by distinguishing between noise and legitimate rotor bar problems, with a noise floor greater than 100 dB.
  • On‐line measurements: All testing is done on‐line, in less than 75 seconds in normal mode, to find problems before they cause additional motor
  • Range and accuracy:  Can accurately test motors under varying load conditions  and  includes two current probes to cover a wider range of current from 5A to 1000A.
  • Portable and safe: Needs only one input from a current probe clamped directly to one of the phase leads or the secondary side of a CT at the motor MCC or breaker.  Processor is powered through the USB connection or 100 to 200 V 50/60 Hz power supply.


  • Rugged data acquisition unit with Windows operating system and pre-installed software for Iris Power MDSP3 (Panasonic Toughbook or similar)

Group Created with Sketch. Applications

  • Rotor Core damage: Broken bars cause local temperature increases and arcing leading to rotor core damage
  • Premature degradation of bearings: Broken rotor bars cause torque and speed oscillations on the rotor. This degrades the bearings
  • Rotor bar movement and failure: Broken rotor bars can lift out of the rotor slot due to centrifugal force or pieces of them can break off and cause a stator winding failure
  • Rotor bending: Large air pockets in rotor windings cause non‐uniform bar expansion leading to rotor bending and unbalance
  • Rotor eccentricity: For the rotor rotating off‐center, both static and dynamic eccentricity in conjunction with the resulting unbalanced magnetic pull  can lead to: 1) high vibration levels from rotor unbalance, 2) a rotor to rub against the stator bore which can cause a stator winding failure