ELD V2 EARTH LEAKAGE RELAY
Issue: R8, Date: 10/08/2011, CRN: 8530
ELDB006 Rev8 ELD V2 (2002) Earth Leakage Protection Relay User Manual
Page 10
5
ELD Earth Leakage Breaker-Operation & Testing
5.1
Description of Operation
The Ampcontrol ELD V2 Earth Leakage Relay is electronic in design and is based on microprocessor technology.
The ‘Healthy’ LED flashes to indicate correct operation of the microprocessor. The Relay uses a toroid to measure
earth fault current. A definite time operating characteristic is provided with adjustable trip sensitivity and time delay.
When a fault occurs and the trip level and time delay is exceeded the relay’s trip function is activated, which operates
the trip contacts connected in the system control circuit. The trip ‘LED’ is ‘On’ when a trip occurs. 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 facia of the relay. The ‘relay’ LED is ‘On’ to indicate the relay is energised.
A ten-segment LED bar graph indicates the % of leakage level being detected. This reading can be remotely
monitored/displayed using the 4-20mA Output of the Relay. When the relay measures currents with frequencies
much greater than 50Hz, the bar graph LED fast flashes (5Hz) instead of being steady. Should the high frequency
current persist until the time delay is exceeded the relay will trip and the ‘Har.Trip’ LED (Harmonic Trip) will be
illuminated.
The ELD V2 Earth Leakage Relay is housed in a stainless steel case and can be either ‘DIN Rail’ mounted or ‘Panel
Mounted’ through a 69 x 39mm cut out. When panel mounted the front of the ELD Relay is designed to provide IP-
56 ingress protection. There is provision to prevent unauthorised adjustment of the trip settings by sealing the post
(in front of the knurled nut) with a lead seal, thus inhibiting the unauthorized removal of the front fascia cover.
An internal switch mode power supply allows the ELD to operate from 25.6VAC to 132VAC or 20VDC to 185VDC.
The ELD V2 Relay has been designed and tested for use on fault-limited systems. To ensure maximum protection
the earth leakage system should be used in conjunction with the other protection systems covered by AS/NZS 2081.
The collective systems are designed to limit touch and step potentials.
The relay is also suitable for industry where equipment or system earth leakage protection is required. The relay is
not suitable for personal protection, which requires trip levels of 20-30mA, with instantaneous operation. (Refer
AS/NZS 3190).
The ELD Relay continually monitors the toroid and if the connection is lost the relay will trip and flash the ‘CT Fault
LED’. See following Caution:
CAUTION!
The ELD relay includes a circuit for continually testing the toroid connection. The
resistance of the wiring between the relay and toroid must be kept below 1ohm. If this
is not done then a “CT” fault will be detected and the relay will trip.
5.2
Methods of Earth Leakage Protection
The ELD V2 Relay is suitable for the two methods of protection used. They are the Core Balance and Series Neutral
earth leakage protection systems. (See Section 4.3,
Methods of Earth Leakage Protection
, for details).
