Section 4: Control & Logic Functions; Autoreclose (79); Synchronising - Siemens 7SR224 Manual

Section 4: Control & Logic Functions
4.1

Autoreclose (79)

Autoreclose sequences can be specified differently for Phase, Earth, Externally Initiated and SEF faults.
Sequences should be simulated for each applicable different fault type with the actual relay settings required for
service installed in the relay.
The relay requires that the correct indications are received at the CB auxiliary contact inputs and that the injected
current and voltage used to generate protection operations are timed to the autoreclose sequence to provide a
realistic simulation of the actual system conditions.
The Instruments Menu contains Autoreclose Meters for the Autoreclose State and the Shot No. which are useful
during sequence testing.
The time stamped Events listing can be downloaded from the relay to a PC to allow diagnosis of the sequence
including measurements of sequence Dead Times and other timing without the use of external measuring
equipment or complex connections.
4.2

Synchronising

The optional Synchronising function provides (Re)closure modes which utilise the synchronising voltages to
impose restrictions on the closing of the recloser to allow co-ordination with other devices in the network. Correct
operation of the application of blocking for all combinations of live and dead line and bus voltage should be
checked for manual closing operations and during the testing of autoreclose.
Enabled/Disabled
DLC
DBC
CS
DLDB
Apply 3 phase nominal voltage to the relay and single phase voltage to the Vx Synchronising input. Ensure that
the synchronising voltage is of the correct phase to represent an 'In Sync' condition. Check the Line Volts and
Bus Volts voltage magnitudes are displayed correctly on the Sync Meters and that the Voltage Diff and Phase Diff
are shown as approximately zero.
Voltage (Vb/Vab etc) Applied Line Volts
.............................
Magnitude
Phase
Reduce Line and Bus voltages from nominal in turn to measure the Dead Line and Dead Bus settings. Increase
the voltages in turn to measure the Live Line and Live Bus settings.
Live Setting
Line Volts
Bus Volts
©2010 Siemens Protection Devices Limited
7SR224 Argus Commissioning & Maintenance Guide
Tested Notes
Measured Line Volts Applied Bus Volts
Dead Setting Live Pickup
Measured Bus Volts
Dead Pickup
Chapter 6 Page 64 of 73