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 16 of 23
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6
PRODUCT OPERATION
6.1 Logical Operation of the EFL Relay
The following flow chart provides an insight into the logical operation of the EFL Relay. Individual test
functions are presented as sub-processes and the functionality of these tests can be seen in the
individual test flow charts.
Figure 6.1: Logical Operation of the EFL Relay
– General Overview
EFL Relay
Energised
Are there any
latched trips?
Tripped State
Keep MCR and/or CBR Open
Is the main
contactor already
closed?
Open CBR: FC (Logical) Trip
MC closed prior initial EFLO
test
Enter Tripped State
Open MCR:
EFLO Trip
Outlet failed EFLO test
Enter Tripped State
Has the
‘Back emf’ timer
expired?
Voltage
exceeds permissible
threshold?
Phase to
earth impedance
> 1MΩ?
Is UV Protection
Activated?
Measured
Voltage > 50% of
Setting?
Yes
No
Yes
No
No
MCI
input matches the
RUN input?
Yes
No
Yes
Open CBR: FC (Logical) Trip
MCI & Run Input
Discrimination
Enter Tripped State
Is the MCI
input closed?
Yes
No
Yes
Yes
Voltage
exceeds permissible
threshold?
Yes
No
Open CBR: FC (Electrical) Trip
Fail to Close (FTC)
Enter Tripped State
No
Open CBR: FC (Electrical) Trip
Fail to Open (FTO)
Enter Tripped State
Yes
Open MCR:
Under Voltage Trip
Line voltage < 50% of Setting
Enter Tripped State
No
NO
Reset Pressed
FC Trip:
Push Button on EFL
EFLO / UV Trip:
Digital Input
No
Yes
