Ampcontrol CSM Pty Ltd - ABN 35 000 770 141
ECD User Manual
ECDB005R0 13/03/2020 13:12 Page 10 of 21
4 ECD RELAY OVERVIEW
The ECD is an intrinsically safe electrical protection relay designed for operation in underground coal mining applications. It
provides earth continuity protection in accordance with AS/NZS 2081:2011 ensuring the integrity of the earth connection
through a trailing or reeling cable is maintained. Earth Continuity protection is another layer of protection that, along with earth
leakage protection, can help keep step and touch voltage potentials at a safe level by ensuring the earth resistance is below a
determined safe level.
The ECD relay is based on microprocessor digital logic, and features a user friendly LED and switch interface. It is installed
within a compact, DIN rail mounted unit with pluggable connectors that can easily be changed out in the event of a problem with
the relay.
The relay contains an internal IS barrier.
Key Features
• Compact size
• DIN rail mounted
• Simple wiring and installation
• 6 settings for trip time
• 6 settings for trip level
• AS/NZS 2081:2011 Compliant
• IEC 60079 Certification
• SIL2 Capable (See appendix B)
Typically the ECD relay will be connected to the pilot conductor of a trailing or reeling cable. With the pilot conductor terminated
to earth through a diode, the relay measures the resistance of the pilot-earth loop (series resistance), to ensure the integrity of
the earth conductors, and the pilot to earth resistance (shunt resistance), to ensure the integrity of the pilot-earth loop. If these
tests fail the ECD will trip, de-energising its output relay which can be used to switch a contactor, circuit breaker or for
signalling.
The ECD can be configured for latching or non-latching operation and has a remote start option.
The ECD relay can also be used as an IS interlock with the pilot terminal connected to a circuit that passes through interlocks
and switches.
CAUTION!
A safe resistance level for the pilot-earth loop should be determined by risk assessment
and analysis of the system.
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