What are the parts of contactor?
A contactor consists of three basic parts: the operating coil, the associated magnetic circuit and the contacts that are actuated by the coil.
What are the different types of contactors?
There are different types of contacts in a contactor, and they are; auxiliary contact, power contact, and contact spring. The power contact has two types that are; stationary and movable contact. Material for making contacts must have a high welding resistance and stable arc resistance.
Why contactor is used?
A contactor is an electrical device which is used for switching an electrical circuit on or off. These contacts are in most cases normally open and provide operating power to the load when the contactor coil is energized. Contactors are most commonly used for controlling electric motors.
What do the numbers on a contactor mean?
These auxiliary contacts (also called control contacts) each have an order number and a function number. The first number is used consecutively (order number) and the second number specifies the type of contact (function number).
What are the three parts of a contactor?
The contacts are the current-carrying part of the contactor. This includes power contacts, auxiliary contacts, and contact springs. The electromagnet (or “coil”) provides the driving force to close the contacts. The enclosure is a frame housing the contacts and the electromagnet.
How many ohms should a contactor have?
The meter should read from 10 to 100 ohms. If the meter does not, the coil is bad and must be replaced.
What is the main difference between relay and contactor?
A contactor joins 2 poles together, without a common circuit between them, while a relay has a common contact that connects to a neutral position. Additionally, contactors are commonly rated for up to 1000V, while relays are usually rated to only 250V.
What is a contactor?
Contactors are compact and can be field mounted easily. Usually, these devices feature multiple contacts. The contacts are mostly normally open, and they provide operating power to the load whenever the contactor coil is powered. Contactors are popularly used with electric motors.
How do contactors handle large loads?
The contactors contacts are able to rapidly open and close, which is why they are able to handle larger loads. Since contactors are designed to rapidly open and close contacts, moving contacts may bounce as they rapidly collide with fixed contacts.
What should I look for when buying an electrical contactor?
Check for a separate auxiliary output contact on the contactor. Some contactors have an extra set of slots labeled with the letter A. These auxiliary spots signal parts of an electrical device that require a lower voltage to operate. The auxiliary output contacts should be rated at 120 volts.
How do you wire a contactor to a contact block?
Use a screwdriver to loosen the holding screws in the contact blocks for the wires. Insert the wires only so far that no insulation is pushed into the contact area of the block. Make sure that no stray strands are jutting out from the contact block. Tighten the screws on the contact blocks. Energize the contactor.