Each of the sets of windings should read about the same ohms value. Keep the multi-meter set for 30,000-ohms and touch one test lead to one terminal and the other to another terminal. 3 Layer wound then the windings will have a small difference between the three. With a lift the windings will be the same resistance near enough. For a 15Kw you will be down in the less than 5 Ohms range. Test for direct shorts in the motor's power windings in induction (non-brush type) motors. There may be a small difference depending on how the windings are laid down.
You may find that when it runs ungrounded that the casing becomes live at up to supply voltage. Also, at this level, standing voltages across the item being measured (e.g. At this level it is important to use test equipment that will minimize errors introduced by the test lead resistance and/or contact resistance between the probe and the material being tested. If there is any reading on any of these then the motor is bad, do not use it. A low resistance measurement is typically a measurement below 1.000 ohm. With a multimeter set to low ohms (usually 200), test between each winding terminal and the metal casing of the motor. It will usually be low enough (under 30 Ω) for the audible continuity indicator to sound.Īlso to know is, how do you check a motor with a multimeter? The smaller the motor, the higher this reading will be, but it should not be open.
How to Test Your Spindle Motor for Open or Short in Windings
Remember that the three phases have identical windings or nearly so!Ĭonsidering this, how do you check motor windings with a multimeter? The ohms reading for each winding must be the same (or nearly the same). 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 ).