Implementation - GE MiCOM P40 Agile Technical Manual

P14x
3

IMPLEMENTATION

Autoreclose functionality is a software option, which is selected when ordering the device, so this description only
applies to models with this option.
Autoreclose works for phase overcurrent (POC) earth fault (EF) and sensitive earth fault (SEF) protection. It is
implemented in the AUTORECLOSE column of the relevant settings group. In addition to the settings contained in
this column, you will also need to make some settings in the blocking cells of the relevant protection columns.
The Autoreclose function can be set to perform a single-shot, two-shot, three-shot or four-shot cycle. You select
this by the Number of Shots cell in the AUTORECLOSE column. You can also initiate a separate Autoreclose cycle
for the SEF protection, with a different number of shots, selected by the Number SEF Shots cell. Dead times for all
shots can be adjusted independently.
An Autoreclose cycle can be initiated internally by operation of a protection element, or externally by a separate
protection device. The dead time starts in one of two cases; when the circuit breaker has tripped, or when the
protection has reset. You select this using the Start Dead t On cell.
At the end of the relevant dead time, a CB Closed 3 ph signal is given, providing it is safe for the circuit breaker to
close. This is determined by checking that certain system conditions are met as specified by the System Checks
functionality.
It is safe to close the circuit breaker providing that:
only one side of the circuit breaker is live (either dead line / live bus, or live line / dead bus), or
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if both bus and line sides of the circuit breaker are live, the system voltages are synchronised.
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In addition, the energy source powering the circuit breaker (for example the closing spring) must be fully charged.
This is indicated from the CB Healthy DDB input.
When the CB has closed, the reclaim time starts. If the circuit breaker does not trip again, the Autoreclose function
resets at the end of the set reclaim time. If the protection operates during the reclaim time the device either
advances to the next shot in the Autoreclose cycle, or if all reclose attempts have been made, goes to lockout.
CB Status signals must also be available, so the default setting for CB Status Input should be modified according
to the application. The default PSL requires 52A, 52B and CB Healthy logic inputs, so a setting of both 52A and 52B
would be required for the CB Status Input if used with the default PSL.
P14xEd1-TM-EN-1
Chapter 13 - Autoreclose
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