Ampcontrol Pty Ltd
– ABN 28 000 915 542
EFL PROTECTION RELAY USER MANUAL
MAG-178 Version 5
– MARCH/2020
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
Page 18 of 23
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If the MCI remains open for >15 seconds before the relay believes the burp sequence has ended, the
relay will operate as per normal operation. That being, the Back EFM timer will initiate and then the relay
will perform the standard EFLO tests upon completion.
6.3 Frozen Contactor (FC) Protection Function
The EFL
’s FC Protection Function provides frozen contactor and contactor loss of vacuum protection for
the connected outlet as per AS/NZS 2081:2011 requirements. The EFL Relay provides this protection in
two forms: logical protection and electrical protection.
The FC (Logical) Protection Function is initiated when a discrepancy is observed between the position of
the Main Contactor (MC) and the position of the Main C
ontactor’s interposing relay. A discrepancy will
indicate that the MC is either welded shut (Failed to Open) or frozen open (Failed to Close). The position
of the MC is monitored by the EFL Relay by wiring an auxiliary contact of the MC to the MCI input. The
position of the MC interposing relay is monitored by the EFL Relay by wiring an auxiliary contact to the
RUN input of the relay.
The FC (Electrical) Protection Function monitors the voltage on the load side of the main contactor via
the HV barrier. When the contactor is opened, the EFL Relay will wait a period of time for the Back EMF
of the supplied motor to subside (determined by the Back EMF time setting) before applying the test
conditions to the voltage measured on the outlet. After the Back EMF timer has expired, if the measured
voltage exceeds the test conditions of 25Vac or 60Vdc, then the EFL Relay will initiate an FC (Electrical)
trip.
Both the FC (Logical) trip and FC (Electrical) trip will result in the EFL Relay opening its CBR output
relay, which should be wired into the tripping circuit of the upstream device (e.g. circuit breaker).
An FC trip will be latched in the memory of the EFL Relay and can be reset by pressing the FC Trip
Reset Button on the fascia of the EFL Relay (after the fault condition has been investigated and
rectified). FC trips cannot be reset via the externally wired remote reset.
NOTE
To
reset an FC trip
, the button on the fascia of the EFL Relay must be
pressed. A FC trip is not able to be reset unless the EFL Relay’s super
capacitor is charged (refer to Section 6.6).
