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

How are contactors rated?

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

Can I use a higher amp contactor?

Yes.... you can use a 40A or 50A replacement contactor. Be sure to ID all the wiring before disconnecting it.

Why are motor starters rated in horsepower?

They make sure that the required amount of current passes to the motor and help with the temperature control in the motor. All motor starters share certain power control functions. They are rated by current (amperes) or power (horsepower) and have remote on/off control and motor overload protection.

Can I replace a double pole contactor with a single pole contactor?

Yes, a 1 pole can be replaced by a 2 pole, and the 2 pole provides additional switching capabilities.

1&2 Pole Contactors/ What Technicians Need To Know

30 related questions found

Can I replace a 30 amp contactor with a 40 amp contactor?

A 30 Amp one can be replaced with a 40 Amp one. It fits in the space if it's not too big.

Can I replace a 35 amp contactor with a 30 amp?

To find a replacement air conditioner contactor, you should match three things. ... You should match the resistive amps rating of the contactor. In a normal residential system, this will be typically 25, 30, or 40 amps. It is alright to replace a unit with one having a higher rating but not one with a lower rating.

How do you choose a contactor?

When selecting a contactor, please make sure that the contactor's rated current is specified for the AC-3 load type. Ensure that you are looking at the right table. You can see the rated current for the AC-3 load is lower than the rated current for the AC-1 load.

How many amps does a contactor coil draw?

The Coil does not draw . 5 amps or 55 watts.

What is AC1 and AC3 rating of contactor?

The difference between AC1 and AC3 contactors is AC1 contactor is used for less inductive loads such as resistive loads (the power factor of the load is near about 1) but AC3 duty contactors are used for high inductive, squirrel cage motors which will be off during the motor is running condition.

Can I replace a 40 amp breaker with a 30 amp?

In general, NO. Doing so is very dangerous and could start a fire! 10 gauge wire requires at most a 30A breaker, whereas 8 gauge requires at most a 40A breaker.

What does Fla mean on a contactor?

The "FLA" (Full Load Amps) spec is the most important rating for most applications, and the 30-amp FLA of this contactor meets/exceeds your 25-amp minimum spec.

What is the difference between Fla and RLA?

FLA: Full-Load Amps: Amount of amperage drawn when motor is working at rated horsepower. RLA: Running-Load-Amps: Same as FLA. LRA: Lock-Rotor-Amps: A motor draws a surge of amperage when it starts to get the rotor rotating and to achieve the rated horsepower.

Why would a contactor burn out?

Reason for coil burns: Coil may burn when the voltage applied to the contactor coil ends is lower or higher than normal. In addition, dust and foreign bodies in the air gap facilitate this. ... To prevent coil burning, the coil must be fed at the voltage and current values specified in the catalog.

Can I replace a 25 amp contactor with a 30 amp?

Can I replace a 25 amp contactor with a 30 amp? You should match the resistive amps rating of the contactor. In a normal residential system, this will be typically 25, 30, or 40 amps. It is alright to replace a unit with one having a higher rating but not one with a lower rating.

What is a 4 pole contactor?

4 pole contactors are electrically controlled switches (relays) used for switching an electrical power circuit. A contactor is typically controlled by a circuit which has a much lower power level than the switched circuit, such as a 24-volt coil electromagnet controlling a 220-volt motor switch.

What are the major differences between a contactor and a motor starter?

A contactor is an electrically controlled switch similar to a relay. Whereas, a starter is a contactor with the addition of an overload relay. A contactor applies voltage to a contactor coil to close the contacts and to supply and interrupt power to the circuit.

How are motor starters rated?

The starters are rated by power (horsepower, kilowatt) and current (amperes). They provide the necessary overload protection for the motor.

What two types of motor protection protect the motor when starting and running?

The motor branch-circuit is protected from the full range of currents using two overcurrent protection devices, the motor overload protection device and one of four types of short-circuit ground-fault protection devices.

Is it bad to oversize a breaker?

Oversizing a circuit breaker can be a safety concern. If there is a direct short in an appliance a breaker will kick off even if oversized, but if there is simply a crossed or burned wire it may not turn off. This would cause a possible shock hazard.