Pouring water on an Induction Motor may stop it working, due to the lowering of the insulation resistance of the internal motor coil windings.
The coil windings are located inside the metal case of the induction motor, and are what generates a magnetic field, which makes the motor turn.
This article will focus on what are known as ‘three phase’ Induction Motors, which have three sets of coil windings inside the motor.
The internal motor windings are wound together in a component known as a ‘Stator’.
Each winding is electrically separated by an insulation layer on the copper wire that makes up a stator winding.
Therefore there should be a high level of electrical resistance between each of the three coils.
This ‘Insulation Resistance’ is typically above 2 Mega Ohms in a correctly operating Induction Motor.
However if the coil windings became wet, then the insulation resistance would drop to a low level, which would prevent the motor from operating, due to a short circuit between the coil windings.
The good news is that induction motors can usually be dried out, and therefore returned to having a high insulation resistance between the Stator coils.
It is of course vital that the motor is disconnected from the electricity supply, and that only a qualified person carries out the work.