Is contactor rating per pole?

Is contactor rating per pole?

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

How are contactors rated?

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

Is a 3 pole breaker 3-phase?

The three-pole breaker operates via the same method as a single-pole breaker. Used most often in a three-phase electrical system, a three-pole breaker connects three different conductors, such as is often required by heavy duty industrial motors.

How do you size a 3-phase breaker?

For 3-phase loads, you divide the VA by the nominal voltage and by the square root of three (approximately 1.732). If your total 3-phase load in a 480V system is 50,000VA, what size breaker do you need? 50,000VA ÷ (480V × 1.732) = 60.2A. The next size up is 70A.

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.

Can a single phase contactor be rated per phase?

Since motors are usually rated in output mechanical power, there can be only one rating. They are never rated in power per phase. If a contactor is rated for use with either single-phase or three-phase motors, it would have a single-phase and three-phase power rating.

How are AC-3 contactors rated per pole?

In the datasheet it says that for AC-3 loads (1) the rated operational current [Ie] is 32 A, and (2) the motor power rating is 7.5 kW at 220..230 V. These numbers match, since 32 A * 230 V = 7360 W. On the Technical FAQ pages of this manufacturer it says: “Contactor current ratings are per pole.

How to wire a single phase motor through a 3 pole contactor?

Then you connect the 2 motor leads to T1 and T3. Using this method, the current is balanced between the 3 poles on the overload. The below wiring diagram shows how we would assemble a complete motor starter, with a start/stop button for a single-phase motor, utilizing a 3-pole contactor.

How is the current rating of a contactor determined?

The power ratings would also be stated separately for each motor voltage rating for which it might me used. Practically the kw & cont. current rating of the contactor must not smaller than kw & FLA of the motor.