Ampcontrol OCS - 7.4 Earth Fault Lockout

Ampcontrol Pty Ltd – ABN 28 000 915 542
OCS USER MANUAL
MAG-182 Version 5 – FEB/2020
Uncontrolled Copy - Refer to Ampcontrol Website for Latest Version
Page 34 of 72
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– NOT TO BE REPRODUCED IN PART
7.3.1 Pilot Interlock
Table 10: Protection Element - Earth Continuity Pilot Interlock Trip Characteristics
Parameter
Action
Power Cycle
Trip status maintained
Reset
Requires a general reset after the trip condition has cleared.
Alternatively the trip can be automatically reset depending on the
status of the EC Latch parameter.
Trip Actions
Open Main Contactor Relay
Prevent Main Contactor from closing
Active Period
Always active
Logging
Always logged
Parameters
Trip time
Trip latch enable
Monitoring
Resolution of Series and Shunt measurements is as per 7.3.1 & 7.3.2.
7.3.2 Pilot Remote Start
Remote start mode can be used to allow the start sequence to be initiated from the load via the pilot
signal. In remote start mode, the PLC cannot force the start of the outlet. It can however prevent the
outlet from starting.
The remote start setting requires the following sequence for a start to be triggered:
1. All trips must be clear.
2. The PLC Comms enable bit must be enabled for a remote start condition to be possible and
accepted.
3. The pilot resistance must be detected above 90Ω to ensure a start resistor is in place.
4. As soon as the resistance calculation drops below the EC series threshold a start is triggered.
(Note that the EC series protection function will still be operating, and the start will not be
triggered if the EC measurement is above the set threshold).
5. If the EC resistance falls below 90Ω, but remains above the EC series threshold it will result in a
remote start error trip after 1 second.
6. The start sequence (EFLO, IT, MC closing) starts immediately after the trigger.
7. The start resistor must remain shorted out by the start button for the duration of the pre-start
tests.
8. If the EC resistance does not return to above 90Ω within 5 seconds after the outlet closes, the
Protection Element will trip on “Remote Start Stuck”.
9. After a start has been triggered, the EC resistance must return above 90Ω before another start
can be triggered.
10. The Remote Start Fault is automatically reset once the EC resistance returns above 90Ω. (An
external reset is not required)
7.4 Earth Fault Lockout
The Protection Element can provide a two-step insulation test as part of the Earth Fault Lockout
protection function. The initial test is the mandatory intrinsically safe test and can be followed by an
automatic High Voltage ‘Insulation Test’.