Power Contactor

A power contactor is rated by the number of times it can turn a motor on and off without generating excessive heat, noise, or welding contacts together. When selecting and supplying power contactors, we assess the duty cycle of the motor, how the motor starts, and what type of load will be connected to the contactor. The operation of a contactor controlling a motor that is started directly across the line is different than the operation of a contactor controlling a capacitor bank, or the operation of a contactor controlling a reversible starter. As part of our selection process, we ensure that the making and breaking capacities and coil voltages of the contactor selected match those of the control circuits of the load, as well as ensuring that the drop-out from the control circuit does not occur during periods of low voltage.

Our portfolio of Power Contactors includes Schneider and Siemens Power Contactors as well as Contactor and Overload Relay Combinations to be used in MCC Panels, PCC Panels and Motor Starter Feeders. The size of a contactor is not selected solely on the kW rating of the motor. We take into consideration the Utilisation Category, the Ambient Temperature inside the Enclosure, and the Number of Starts per Hour. In addition, to control the inrush current and improve contactor contact life, separate contactors are used in APFC Panels to operate Capacitor Duty Contactors with pre-charge resistors.

The practical placement of the panel's mount will help with termination of cables and keeping equipment cool (heat dissipation). The control wiring will have ferrules on each wire and be looped to allow for simple replacement during maintenance. All mechanical and electrical operations must be verified before integration.

When used in USA facilities, power contactors will can deal with continuous cycling (frequent switching), variable voltage levels, and consistent pickup/dropout without chatter.