The smaller the air gap is, the lower that reluctance, and thus the higher the magnetic flux (which is the magnetic analog of current), allowing the motor to work more efficiently and at a higher power.

Air Gap monitoring on Hydro Generators can help identify many geometric problems including misalignment, magnetic unbalance, rotor shorted turns, loose pole and stator movement that would otherwise lead to damage from magnetically induced heating or rotor-to-stator rub.

The longer air gap thickness between the motor stator and the rotor, the more cooling liquid flowing through the air gap, which results the heat exchange becomes better between the motor and the cooling liquid and the temperature rise of the motor is lower.

The air gap between the pole pieces and the armature is kept very small to keep the field strength at its highest value. This is due to the reason the flux lines can pass through iron very easily than the air gap. The small air gap generates high voltage.

Capacitive sensors from Micro-Epsilon designed for non-contact displacement and distance measurements reliably monitor the operation. Therefore, the sensors are used to measure the distance between the stator and rotor and to monitor the so-called rotor gap.

As these motors have considerably high starting torque with low starting current, these motors can be started on load. The external resistance is used only for the starting purpose, after which the motor gradually picks up the speed, the resistance gradually cut-off.

Rotor resistance starter

Functionally, slip rings provide a continuous transfer of power, signals, or data. Specifically, in AC motors, they transfer resistance to the rotor windings. Commutators, on the other hand, are used in DC motors to reverse the polarity of current in the armature windings.

Slip rings find use in the startup of asynchronous electric motors — in the ac induction motors known as wound-rotor motors. Here, they don’t transfer power. Rather, they insert resistance into rotor windings.To be clear — a slip ring in a motor is not the same as a commutator.

1. What will happen if DC shunt motor is connected across AC supply? Explanation: In case of parallel field connection, it won’t rotate at all and will start humming and will create vibrations, as a torque produced by positive and negative cycle will cancel out each other. DC motor will be heated up and it may burn.

1 Answer. Most AC fans have induction motors and as such won’t work on DC. You will most likely need an inverter, to convert from 12VDC to the AC voltage that fan requires.

Leaving any fan on all night does have the potential to catch fire, but the same can be said for leaving a fan on all day. Any appliance left running for a long period of time can cause the appliance to overheat and catch fire. One of the leading causes of death in a fire is due to smoke inhalation.