How do I know if my 3 phase motor is bad?
Using Ohm meter: Disconnect all power from machine. 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 .
How do you check if a motor is working?
With a multimeter set to low ohms (usually 200), test between each winding terminal and the metal casing of the motor. If there is any reading on any of these then the motor is bad, do not use it. You may find that when it runs ungrounded that the casing becomes live at up to supply voltage.
Why is my 3 phase motor humming?
If the motor hums but won’t turn when power is applied, it indicates that one phase of a three-phase motor is open, or the start winding of a single-phase motor is open. … This problem may be caused by having too large a load for the motor or a bearing that needs lubrication.
How do you troubleshoot a 3 phase motor?
How to Troubleshoot a 3-Phase Electric Motor
- Take input voltage to the motor using the volt ohmmeter. …
- Examine the motor’s electrical connections and terminals. …
- Remove motor voltage and disengage the motor from the machine that it is running. …
- Check the motor for heat or burnt smell.
How many ohms should a 3 phase motor have?
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 calculate the resistance of a 3 phase motor?
R in ohms = Rated voltage /(rated current x1. 732×3. 5). Example : 2000kw motor, rated voltage is 6600v, rated current is 175A, then R= 6600/(175*1.732*3.5) = 6.22.
What is the minimum insulation resistance of a motor?
It is recommended that the insulation resistance of the motor should at least be 1 MΩ1）, and for the voltage to ground of 200 V, I0r should be 200 μA or below.
How do you test a 3 phase motor inductance?
Or- If you don’t have inductance meter, the inductance of the coil can be measured by the following method.
- Measure the resistance(R) of coils(phase to phase)
- Feed AC voltage (V), 50 Hz to coils and measure the current(I)
- Calculate impedance of the coils Z=V/I.
- Calculate reactance(XL) of the coils by XL=√(Z^2-R^2)