BCH Electric Limited

  There is a staggering variety of motor applications, each different, and each with particular overload protection requirements. Exactly how relays achieve their performance to match these requirements is what is critical and what, essentially, separates conventional relays from the newer, electronic models. What is an electronic overload relay? The electronic  overload relay  is a microprocessor-controlled device designed to protect three-phase and one-phase motors against excessive temperature rise from overload and phase failure. Internal current transformers cont i nuously measure the actual motor current in each phase. When the preset operating value is reached, a trip occurs. After restoring voltage, the relay reverts to its position before the interruption. Electronic overload relays are the alternative to thermal overload relays. An electronic overload relay offers reliable and fast protection for motors in overload or phase failure. The electronic  overload...

Overload Relay:  Overload relay is an electrical device designed as the heating prototypes of the electric motor. It breaks up the flow of current when the heat-detecting device in the relay attains a fixed temperature. An overload relay device can be prepared with a heater linked with generally closed connections that unlocks when the heater gets extremely hot. Principle Of Overload Relay Operation When excess current is drawn into the motor, it causes an overload. This causes overheating of the motor and may damage the motor. Thus, it is required to protect the engine, circuits, and branch circuit components from overload conditions. Overload relays protect the motor and branch circuit components from an overload. Overload relays monitor the flow of current in the circuit. Suppose the current rises above a specific limit over a particular time. In that case, the overload relay will trip, performing a supplemental contact that suspends the motor control circuit. This leads to th...