Ampcontrol OCS - Table 11: Protection Element - Earth Fault Lockout (EFLO) Trip Characteristics; Table 12: Protection Element - High Voltage Insulation Test Characteristics

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OCS USER MANUAL
MAG-182 Version 5 – FEB/2020
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7.4.1 Intrinsically Safe EFLO
Table 11: Protection Element - Earth Fault Lockout (EFLO) Trip Characteristics
Parameter
Action
Power Cycle
Trip status maintained
Reset
Requires a general reset after a failed test
Trip Actions
Prevent Main Contactor from closing
Active Period
Single test performed during the start sequence
Logging
Logged when test fails
Parameters
No parameters
Monitoring
Last test value stored, for each phase. Value stored is from 0-150%,
where 100% is 1MΩ (all phases in parallel).
The initial earth fault lockout function tests the resistance of the three phase lines to earth by applying
an intrinsically safe signal prior to the closure of the main contactor in accordance with AS/NZS 2081:
2011. The test is initiated by starting the relay once all starting conditions are met. This test takes 2
seconds. If the value measured is less than the pre-set level a trip occurs.
7.4.2 High Voltage Insulation Test
Table 12: Protection Element – High Voltage Insulation Test Characteristics
Parameter
Action
Power Cycle
Trip status maintained
Reset
Requires a general reset after a failed test
Trip Actions
Prevent Main Contactor from closing
Active Period
Single test performed during the start sequence. Optionally can be
disabled.
Logging
Always logs the measured test result. Trip events are logged
separately
Parameters
Trip Level
Monitoring
Last test value stored.
HV Test Voltage
900VDC (1.1kV System) or 2700VDC (3.3kV System)
If an insulation trip level has been selected, an automatic High Voltage DC ‘Insulation Test’ is carried out
after an Intrinsically Safe Earth Fault Lockout Test has been passed.
During the ‘Insulation Test’ the Protection Element generates a high DC voltage, approaching the peak
system voltage, which is applied between each phase and earth. The Protection Element measures the
voltage on the line and calculates the meg-ohm resistance to earth for all three phases. If the resistance
value is above the pre-set threshold the Protection Element will close its MCR output, allowing the main
contactors control circuit to energise. The insulation test takes 4 seconds.
The results of the insulation test should only be used as a guide to confirm that insulation remains above