Does a contactor have an overload relay?
Contactors are used to control electrical loads and motors without providing overload protection.
What is A1 and A2 on a contactor?
What Do A1 and A2 Mean on a Contactor? A1 and A2 on a contactor typically refer to either end of the electromagnetic coil assembly. Most contactor manufacturers use A1 and A2 to designate the two terminals connecting electrical power to the contactor’s magnetic coil.
What is the difference between overload and overcurrent?
Magnetic circuit breakers, fuses and overcurrent relays are commonly used to provide overcurrent protection. Overload protection is a protection against a running overcurrent that would cause overheating of the protected equipment.
What is contactor overload?
Contactor Overload Relays Overload is where a motor draws a high current above its rated value for an extended amount of time. Overload causes overheating of the motor causing damage. To prevent this from happening devices such as contactor relays are specifically designed for industrial control motor protection.
How does an overload contactor work?
They protect the motor by monitoring the current flowing in the circuit. If the current rises above a certain limit over a certain period of time, then the overload relay will trip, operating an auxiliary contact which interrupts the motor control circuit, de-energizing the contactor.
What is the difference between contactor and overload relay?
Load Capacity Relays are generally classified as carrying loads of 10A or less, while a contactor would be used for loads greater than 10A, but this definition, while simple, gives an incomplete picture. It leaves out any physical differences, or standards.
How to control a three-phase load with a contactor?
A contactor uses a low-voltage signal to control the high-voltage circuit. This low-voltage signal can be controlled by an electrical relay or a computer. Shut off the power to the three-phase load. Depending on the voltage level of the circuit, the wire colors will be different. A three phase load is powered by three power wires.
How do I wire a contactor to an overload relay?
We start by bringing in the 2 power leads to L1 and L2 on the contactor. Then we add a jumper wire from L3 on the contactor to T2 on the overload relay. Please note, as this jumper wire will be carrying line power to the motor it is important the wire gage is selected based on the current load going through the contactor.
How do you balance the current on a 3 phase overload?
This directs the current through from L2 and directs it through the 3 rd phase on the contactor and overload (L3 & T3). 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.
How do you control a low voltage 3 phase load?
This low-voltage signal can be controlled by an electrical relay or a computer. Shut off the power to the three-phase load. Depending on the voltage level of the circuit, the wire colors will be different. A three phase load is powered by three power wires.