Which contactor do I need?

Which contactor do I need?

You should select the suitable contactor according to the number of phases of the load. For example, if you want to control a 3 phase motor, you should use 3 pole contactor. If you want to disconnect the neutral, your choice should be 4 pole version.

What does an HVAC contactor do?

The contactor is essentially a type of switch that receives a low voltage signal (24V) from your furnace to power on. By creating a magnetic field, it pulls down a piece of metal that will connect both of the higher voltage sides.

What does a lighting contactor do?

Lighting contactors are relay switches that control the flow of electricity through a circuit powering the lighting in a given area. A lighting contactor switch operates at a lower but safer load and controls the high voltage/current circuit using an electromagnet. Turn the power off for the entire system.

How do I choose a contactor size?

As per above chart:

  1. Type of Contactor = AC7b.
  2. Size of Main Contactor = 100%X Full Load Current (Line).
  3. Size of Main Contactor = 100%x6 = 6 Amp.
  4. Making/Breaking Capacity of Contactor = Value above Chart x Full Load Current (Line).
  5. Making/Breaking Capacity of Contactor = 8×6 = 52 Amp.

Are AC contactors Universal?

The universal mounting base allows replacement of most contactor brands. The contactor connects the outdoor unit to 220 volt power causing both the compressor and the outdoor fan motor to run. A 1 pole contactor in contrast leaves one leg of the 220 volts connected even when the outdoor unit is not running.

Why do contactors go bad?

Over time, contactors can burn out due to either normal wear and tear or overheating. When a contactor burns out, the component that it supplies electricity to will not be able to turn on. They can get stuck down.

How often should a contactor be replaced?

The important question is, how would you know that your contactor is in dire need of replacement. A good contactor can last for almost ten or so years if it receives regular and annual maintenance. Sometimes, a contactor may simply have to be repaired. For smaller issues, a repair can do the trick.

How long can a contactor be energized?

For example, a properly applied contactor will have a life span of 10,000 to 100,000 operations when run under power; which is significantly less than the mechanical (non-powered) life of the same device which can be in excess of 20 million operations.

Does a lighting contactor need a neutral?

In general, no, a it is not necessary that a lighting circuit, of which a contactor is a part, have a neutral conductor in all cases. The contactor must open all UN-grounded conductors. If the contactor is a single pole, then one of the current carrying conductors must be a groundED (not the groundING) conductor.