Table of Contents
How do you test a 3 phase motor insulation resistance?
Phase Resistance: Take the insulation tester and set it to 500V. Take each end and place it on different permutations of L1, L2 and L3 and record each reading. Phase to Earth Resistance: Take the insulation tester, using the same setting, and check each lead from phase to the frame of the motor.
How many ohms should a 3 phase motor read?
The reading should be between 0.3 to 2 ohms. If it is 0, there is a short. If it is over 2 ohms or infinite, there is an open. You can also dry the connector and retest to possibly get more accurate results.
How do you test motor insulation?
This is how the test works: DC voltage of 500 or 1000 V is applied between the windings and the ground of the motor….A general rule-of-thumb is 10 Megohm or more.
| Insulation resistance value | Insulation level |
|---|---|
| 2-5 Megohm | Critical |
| 5-10 Megohm | Abnormal |
| 10-50 Megohm | Good |
| 50-100 Megohm | Very good |
How do you test an insulation resistance on a motor?
The measurement of insulation resistance is carried out by means of a megohmmeter – high resistance range ohmmeter. This is how the test works: DC voltage of 500 or 1000 V is applied between the windings and the ground of the motor.
How do you troubleshoot a 3 phase motor?
Examine the motor’s electrical connections and terminals. Remove power to the motor and repair any damaged or loose connections. Remove motor voltage and disengage the motor from the machine that it is running. Reconnect motor voltage and see if the motor now runs.
How do you know if a 3 phase motor is bad?
Check all three wires singly T1,T2,T3 (all three phases) to the ground wire. Readings should be infinite. If its zero or reads any continuity at all, then a problem exists with either the motor or cable . If it is go directly to the motor and disconnect from cable and check motor and the cable separately.