Starter

Starter Points : Definition Starter, A device which is used to start and regulate the current to a motor during the staring period. It may be used to make or break the circuit and / or limit the starting current. It is equipped with over current protection devices, such as magnetic contactor with overload relays. There are two types of starter: manual and magnetic. A manual type starter consists of a start and stop buttons are built into the cover. When, we push the start or stop button, a mechanical linkage to the buttons closes or opens the main contacts. The overload relay for running current, over current protection is part of the starter. It is necessary that each motor be provided with a means of starting and stopping and so placed as to be easily worked as by authorized person of the motor. The starter controlling every motor must incorporate means of ensuring that in the event of drop in voltage or failure of the supply, the motor does not start autocratically. If the starter trips, stopping the motor because of overload, reset the starter by pushing the reset button.

Every motor having a rating exceeding 0.37kw must also be controlled by a starter, which incorporate an over current relay with a suitable time delay to look after starting current. The time delay can usually be adjusted and are normally set to operate at 10% above full-load current.

The ideal arrangement is to back-up the over current device in the motor starter with H.B.C (High Breaking Capacity) fuse links. Which have discriminating characteristics, which will carry heavy staring current for larger periods than the ever current device. If there is a short circuit the H.B.C fuses will operate instantaneously and will clear the short circuit. There are many types starter, which are named according to starting method of motor; e.g. D.O.L starter, star-delta starter, auto transformer starter, resistance starter etc. a motor starter consists of a magnetic contactor, thermal relay and push buttons etc.