How is motor contactor rating calculated?

How is motor contactor rating calculated?

Making/Breaking Capacity of Contactor= Value above Chart x Full Load Current (Line). Making/Breaking Capacity of Contactor=1.5×13= 19 Amp. Size of Star Contactor (Starting Condition) = 33%X Full Load Current (Line). Size of Star Contactor =33%x13 = 4 Amp.

How do you size a compressor contactor?

If the compressor is not listed in the table the contactor can always be sized for full voltage starting by selecting a contactor of the next amperage rating larger than the compressors Rated Load Amps (RLA) and then checking the LRA requirements against the rating of the chosen contactor.

How is a contactor rated?

Contactors are rated by designed load current per contact (pole), maximum fault withstand current, duty cycle, design life expectancy, voltage, and coil voltage.

How do I know the size of my contactor?

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.

How can I choose the right contactor for my motor?

The contactor rated current varies according to the voltage and therefore please ensure that you are selecting the right contactor according to the voltage being supplied. As you can see from the picture above.

How are contactors used in an electrical circuit?

The contactors are used for the switching purpose in electrical power circuits. The contactors are commonly used with the big motors which are used in huge industries for several purposes. The contactor is used with the motors to protect the motors from different overload conditions.

How to calculate the size of a contactor?

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

How is voltage calculated for alternating current contactor?

Voltage class of alternating current contactor should be the same with load, and selected contactor should adapt to load. Calculating current of load should conform to capacity class of contactor. That is to say, calculating current is less than or equal to eh rated operational current of contactor.