OICEW-3-1D

Measure insulation resistance

Condition

Aboard ship or in a workshop, given access to 3-phase electrical AC motor and controller, a Megger test meter, and other proper tools and safety equipment.

Performance requirement

Behavior Standard
The student will: During assessment, the student shall, at a minimum:

Measure motor insulation resistance at motor controller

Use megger to perform insulation spot test:

  • de-energize motor, lockout/tagout if necessary
  • verify megger ground connection
  • connect lead to field winding
  • select appropriate test voltage
  • energize meter for 60 seconds, or until reading stabilizes at infinity
  • read meter

Correct insulation resistance measurement to standard temperature.

Correct reading to 40 °C using nomograph or correction chart.

Evaluate insulation resistance value

Compare corrected resistance to IEEE standard.

State whether resistance value is within acceptable limits

See the Engineering Assessment Guidelines for additional specifications of behavior and standards.

Note: This assessment supports KUP OICEW-B2.3, and is assessed in EN-4231 Sea Term IV: Marine Engineering.