The Ampcontrol ELV Earth Leakage Relay uses patented technology (AU2011264414) to characterise earth leakage currents giving superior fault discrimination, particularly in applications involving switching power electronics and variable speed drives.
The ELV is electronic in design and is based on microprocessor technology. It is designed to AS/NZS 2081:2011 Section 6.
The earth fault current is measured using a toroid, with the trip time and trip threshold being able to be independently adjusted using selectors on the relay fascia. When a fault occurs and the trip level and time delay is exceeded the relay’s trip function is activated. A trip will de-energise the trip contacts connected in the system control circuit. The trip condition is latched in non-volatile memory and requires operation of the reset input to clear the trip condition. An internal reset is also provided on the fascia of the relay.
A ten-segment LED bar graph indicates the percentage of leakage level being detected. This reading can be remotely monitored/displayed using the 4-20mA output of the relay.
The ELV relay provides a definite time operating characteristic with adjustable trip sensitivity and time delay. The relay latches when tripped and provides normally open and change-over relay contacts. The relay supports an external reset switch, and a 4-20mA interface allows external monitoring.
The Ampcontrol ELV is the next generation of earth leakage relays and provides wide bandwidth earth leakage protection (earth fault protection) as per AS/NZS 2081:2011. It has been designed for use on earth fault-limited systems, and particularly coal mining applications.
The relay is also suitable for other applications where equipment or system-wide earth leakage protection is required.