Using a multimeter, check the continuity of motor winding from phase to phase ( U to V, V to W , W to U ). Each phase to phase must have a continuity if winding is OK. If any particular phase fails the continuity test, your motor is probably burnt.
How do you check a 3 phase motor to see if it 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 test a Star Delta motor?
Identify the coils, measuring continuity. Connect the motor in delta style using six cables or use a star-delta starter as power of motor dictates. Test all the combinations in one of the ends of the coils, left the other side fixed. There are only two possibilities.
How many ohms should a 3 phase motor have?
The windings (all three in a three-phase motor) should read low but not zero ohms. The smaller the motor, the higher this reading will be, but it should not be open. It will usually be low enough (under 30 Ω) for the audible continuity indicator to sound.
How do you test a motor to see if it is bad?
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.
How do I know if my engine is Delta or Wye?
If leads are numbered 1-6, the winding can usually be connected wye or delta. On machines rated for two voltages, the wye connection is for the high voltage; the delta connection is for the low voltage. For a single voltage rating, most 6-lead machines are capable of wye-delta starting (and will run in delta).
How do you tell if an electric motor is burned out?
You should test the windings for a “short to ground” in the circuit and open or shorts in the windings. To test your motor for short to ground, you’ll need to set the multimeter to ohms and disconnect the motor from its power source. Then inspect each wire and look for infinite readings.
What will happen if star connected motor in Delta?
The Delta connection motor will draw 1.732 times higher current when connected into a star connection mode.
What happens when it is star connected or delta connected?
When you have Star and Delta connected motors, you are working with two different phase voltages within the motor. The Star connected motor shares line voltage across two phases, while Delta connected motor provides full line voltage to each phase.
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.
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)