Electronic Overload Relay has a peculiar tripping characteristic as per the designated CLASS. The tripping characteristic is an Inverse exponential curve of I (Current) Vs T (Tripping Time).

Efficient Micro controller unit (MCU) is used to monitor all activities & take the necessary decisions based on that to implement the proper actions.

Function

This device is used to protect 3-phase motors from over current, single phasing & other such phenomena.

In any of the above cases, the Electromechanical Relay used in the device trips & switches off the motor to protect it. The CT module is of 2 separate CTs fitted on to the device to continuously monitor current flowing through the respective phase. If any unbalancing occurs, the corrective feedback in-turn is given by MCU to act accordingly.

I Vs T is the curve (as per international standard) that states higher the current lesser is the tripping time.

Application

Electronic overload relay is suitable for AC 50/60Hz, voltage up to 600VAC and current up to 60A. It is used as Overload and Phase Loss Protection device. It has independently adjustable STARTING and TRIP delay (O-TIME, D-TIME), Visual Current Setting Dial, Trip Indication, Fail Safe Protection (N type) and Electronic Shear Pin function. The product conforms to IEC60947-1 standard.

EFR (Earth Fault Release)

These are Earth Leakage Testers used to detect leakage current in ground terminal of equipment. The device is CT-based. Tripping mechanism is provided by means of an electro-mechanical sealed relay.