ABB RELION RET670, Applications Manual

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15.2.3.5 Bay Reserve (QCRSV)
M16677-3 v3
The timer tCancelRes defines the supervision time for canceling the reservation, when
this cannot be done by requesting bay due to for example communication failure.
When the parameter ParamRequestx ( x =1-8) is set to Only own bay res. individually
for each apparatus (x) in the bay, only the own bay is reserved, that is, the output for
reservation request of other bays (RES_BAYS) will not be activated at selection of
apparatus x.
15.2.3.6 Reservation input (RESIN)
M16678-3 v3
With the FutureUse parameter set to Bay future use the function can handle bays not
yet installed in the SA system.
15.3 Interlocking (3)
IP15572-1 v2
M13530-4 v4
The main purpose of switchgear interlocking is:
• To avoid the dangerous or damaging operation of switchgear
• To enforce restrictions on the operation of the substation for other reasons for
example, load configuration. Examples of the latter are to limit the number of
parallel transformers to a maximum of two or to ensure that energizing is always
from one side, for example, the high voltage side of a transformer.
This section only deals with the first point, and only with restrictions caused by
switching devices other than the one to be controlled. This means that switch interlock,
because of device alarms, is not included in this section.
Disconnectors and grounding switches have a limited switching capacity.
Disconnectors may therefore only operate:
• With basically zero current. The circuit is open on one side and has a small
extension. The capacitive current is small (for example, < 5A) and power
transformers with inrush current are not allowed.
• To connect or disconnect a parallel circuit carrying load current. The switching
voltage across the open contacts is thus virtually zero, thanks to the parallel circuit
(for example, < 1% of rated voltage). Paralleling of power transformers is not
allowed.
Grounding switches are allowed to connect and disconnect grounding of isolated
points. Due to capacitive or inductive coupling there may be some voltage (for
1MRK 504 163-UUS A
Section 15
Control
Transformer protection RET670 2.2 ANSI 717
Application manual