Manual Close; Synchronising; Reclosure Modes - Siemens 7SR224 Technical Manual

4.2

Manual Close

A Manual Close Command can be initiated in one of four ways: via a Close CB binary input, via the data
communication Channel(s), from the relay CONTROL MODE menu or from the relay fascia function keys. It
causes an instantaneous operation via 79MC Close CB binary output, over-riding any autoreclose (AR) sequence
in progress. When check syncronising is used, the manual close operation is performed using mode settings
which are independent of those of the 79 autoreclose.
Repeated Manual Closes are avoided by checking for Positive edge triggers. Even if the Manual Close input is
constantly energised the relay will only attempt one close.
A Manual Close will initiate Line Check if enabled. If a fault appears on the line during the Close Pulse or during
the Reclaim Time with Line Check enabled, the relay will initiate a Trip and Lockout. This prevents a CB being
repeatedly closed onto a faulted line. Where Line Check = DELAYED then instantaneous protection is inhibited
until the reclaim time has elapsed.
Manual Close resets Lockout, if the conditions that set Lockout have reset i.e. there is no trip or Lockout input
present.
Manual Close cannot proceed if there is a Lockout input present.
With the Autoreclose function set to Disabled the Manual Close control is still active.
4.3

Synchronising

The optional Synchronising function is used to check that the voltage conditions, measured by the voltage
transformers on either side of the open circuit breaker, indicate that it is safe to close without risk of damage to
the circuit breaker of disturbance to the system. The timing of closure, for charging lines which are dead following
fault clearance, is controlled to co-ordinate with other devices.
The window of time in which voltage conditions must be met is applied as a setting or can be disabled such that
an indefinite period is allowed.
4.3.1

Reclosure Modes

The Synchronising element can be set to allow the autoreclose sequence to proceed for various system voltage
conditions. The voltage conditions selected must be met within the Synch Close Window time which is settable
and starts at the end of the deadtime for autoreclose or the receipt of a Close CB command.
The voltage applied to the V
V ,V & V are the LINE voltage.
1 2 3
79 Dead Bar Charge, when set to Enabled, allows AR to proceed when the Busbar voltage is live and the Line is
dead.
Manual Close DBC, when set to Enabled, allows MC to proceed when the Busbar voltage is live and the Line is
dead.
79 Dead Line Charge, when set to Enabled, allows AR to proceed when the Line voltage is live and the Busbar is
dead.
Manual Close DLC, when set to Enabled, allows MC to proceed when the Line voltage is live and the Busbar is
dead.
79 Dead Line & Dead Bar Close, when set to Enabled, allows AR to proceed when the Line voltage and the
Busbar voltage are dead.
Manual Close DLDB, when set to Enabled, allows MC to proceed when the Line voltage and the Busbar voltage
are dead.
79Check Sync Close, when set to Enabled, allows AR to proceed when both the Line and Busbar are considered
live AND other synchronising requirements are met.
Manual Close CS, when set to Enabled, allows MC to proceed when both the Line and Busbar are considered live
AND other synchronising requirements are met.
79 Unconditional Close, when set to Enabled, allows AR to proceed regardless of the voltage condition of the Bus
or Line.
Unconditional Manual Close, when set to Enabled, allows MC to proceed regardless of the voltage condition of
the Bus or Line.
Separate Enable/Disable settings are thus provided for each option for Autoreclose and Manual Close.
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input is considered to be the BUSBAR voltage and the voltages applied to inputs
4
7SR224 Argus Description of Operation
Chapter 1 Page 47 of 70