Ī three phase motor needs all the threephases of the main supply for the motor to start and run. If itszero or reads any continuity at all, then a problem exists witheither the motor or cable. Check all three wires singly T1,T2,T3 (all threephases) to the ground wire. Remember that the three phases have identical windings or nearly so Hereof, how do I test a fan motor. The ohms reading for each winding must be the same (or nearly the same). Testing for short to ground Using Ohm meter: Disconnect all power from machine. AC Motor Winding Resistance Test Check the motor winding resistance or ohms reading using a multimeter or ohmmeter for phase to phase terminal ( U to V,V to W ,W to U ).
Check the readings on your multimeter If your motor is good, it will have little resistance i.e.0 or close to zero. Take the other probe and touch it to the other terminal on the motor. Take one of your multimeter probes and touch it to one terminal on the motor. Thereading that appears on the multimeter screen is the resistance in ohms.Ĭonsidering this, how do you know if a 3 phase motor is bad? First, set your multimeter to the lowest setting, or RX1.Setting. Terminals Configuration of a 3 PhaseMotor The W2U2V2 terminal set is the star side of the 3phase motor while the U1VIW1 is the Delta side of the motor connected to the supply voltage.Īlso, how do you find the winding resistance of a motor? Touch the red (positive) lead of the multimeter to thepositive end of the wire windings around the motor.Touch the black (negative) lead of the multimeter to the negativeend of the wire windings around the motor. The internal wiring of these motors looks like this: Looking at the diagram above, we can assume that the resistance between A1 and AC will be half of. Stepper motors with six wires are unipolar and have one winding per phase (like the bipolar steppers) but with a center tap.
HOW TO CHECK 3 PHASE MOTOR WINDING WITH MULTIMETER HOW TO
Thecurrent in each winding is 120 electrical degrees out of phase with the urrent in the other windings.īeside this, how much winding does a 3 phase motor need? How to identify six-wire stepper motor coil pairs with a multimeter. Continue this process with the start and run terminal. Now connect one lead of the meter to compressor common and other connect compressor uninsulated body place. Now set your multimeter knob on connectivity text or Ohm. The most basic 3- phase induction motorhas three sets of windings, with each phaseconnected to a differ- ent set of windings, Figure 16-4. Now you find and mark your compressor terminal.