Siemens 7SR224 Technical Manual page 341

7SR224 Argus Applications
MODE B 1PTrip-3PLO
In this mode Controller can perform independent single pole TRIP sequences up to the point at which the Lockout
state is reached on any one pole, it then performs a final three pole TRIP and all three
poles are Locked Out together. Controller only goes to 3PTrip-3PLO if and when a 3P Trip and Lockout has to be
performed. If at any point during an AutoReclose sequence a Phase-to-Phase or 3-Phase Fault condition
develops and exists when a Trip output has to be issued i.e. if at the point at which a first pole element operates a
starter is also raised on any other pole, then the Controller reverts to 3 pole Trip and 3 pole Close sequencing and
3PTrip-3PLO as applicable at that point in the sequence.
This mode prevents detrimental LONG TERM 2 phase energisation of three phase loads e.g. motors.
In this mode 2 pole trips are never issued, any fault diagnosed as affecting more than 1 pole will cause a 3 pole
trip which may be followed by 3 pole reclose.
Any fault on a healthy phase during a single pole reclose sequence on another phase will cause a 3 pole trip
which may be followed by 3 pole reclose.
In this mode any single pole CB Trip or CB Close Command is considered to be a long term action and is
therefore diverted to operate all three Reclosers.
In this mode a Line Check Trip or Trip & Lockout Command causes a 3PTrip-3PLO .
In this mode any single manual Lockout Lever Command causes a 3PTrip-3PLO .
In this mode, the single pole Trip and Reclose Command remains pole segregated.
In this mode the Hot Line On Command primes a single 3PTrip-3PLO.
If ARC OFF is selected in Mode B all trips will be 3PTrip-3PLO .
MODE C 1PTrip-1PLO
Mode C applies single pole tripping for all Phase Fault fault combinations. Each pole of the Recloser Controller
follows its own settings and sequence independently. This is the equivalent of having three separately mounted
single pole Reclosers each with its own Controller, each Recloser Controller is, therefore, unaware of the state of
the Reclosers & Controllers on the other poles. This does mean that the sequences on each pole are not
synchronous and are not interlocked, therefore, a fault scenario can develop where for a Phase to Phase fault
one pole could be performing a Fast Trip the other could be performing a Delayed Trip, this is not an issue, one
pole will initiate the tripping action(s) and if unsuccessful eventually both sequences will be doing delayed. Also
different Dead times could be applicable on each of the poles at that point in the two sequences but Close
commands issued by the Sequences are co-ordinated so that both poles close at the same time.
In this mode the Controller performs independent single pole Trip and Reclose sequences, each pole will Lockout
independently. The Controller operates to drive each Recloser pole as an independent Circuit Breaker. Normal
system operating modes will thus be 3P or 2P or 1P for extended periods, this determines the type of protection
elements which can be enabled, Frequency elements and Voltage elements must track the remaining in-service
phase(s). Controller does NOT revert to three-pole Trip and Close sequencing or three pole Lockout if a Phase to
Phase Fault condition exists at any Trip point in the sequence.
In this mode all unbalance protection elements would usually be inhibited, i.e. NPS Overcurrent, NPS
OverVoltage, VT Supervision, CT Supervision, and Broken Conductor. It is NOT expected that Directional
elements will be applied as single pole tripping will change the polarising conditions for the sound poles.
In this mode a CBA Trip or CBA Close Command operates only on the A Pole Recloser, ditto for B and C poles.
In this mode 2 pole trips can be issued, any fault diagnosed as affecting 2 poles simultaneously will cause a 2
separate single pole trips which will be followed by two separate single pole reclose sequences. Close pulses to
the two poles are aligned so that if the 2 trips were resultant from the same fault, re-strike does not occur from the
two phases individually such that the fault is perpetuated by passing it from one phase to the other.
Any fault on a healthy phase during a single pole reclose sequence on another phase can cause a separate
single pole trip which will be followed by separate single pole recloses with close pulses aligned.
In this mode any Line Check Trip will result in a 1PT - 1PLO
In this mode a manual Lockout Lever Command on one pole only acts on that pole, there is no cross linking
action to other poles. A Binary Input '79 Lockout' is required for each pole and each pole has its own manual
Lockout counter.
In this mode the Hot Line On Command primes a single 3Pole Trip and Lockout 3PT - 3PLO .
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