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Key Interlocks (Optional)
After initial installation of the switchgear equipment,
insert all necessary interlock keys into the
appropriate locks. Store all spare keys in accordance
with the owner's established procedures.
Kirk Lock
Figure 9-11 shows the position of the Kirk lock. Turning the key
90° clockwise moves the Stopper Rod up (Figure 9-12 through
Figure 9-13) and prevents the undercarriage from rolling.
By default, a Kirk lock having an Auxiliary switch turns NO
to NC.
Figure 9-12: Initial Stopper Rod Position
Figure 9-13: Locked Stopper Rod Position
CAUTION
Refer to the key interlock schematic included in the
summary furnished with the equipment to determine the
sequence of operation and the correct number of operating
keys required. Improper use of spare keys will defeat the
interlocking scheme.
Preferred Lock Out Tag Out Procedure (LOTO)
There are two basic methods to LOTO a circuit breaker from
service. Option A below would be followed when the main bus
is energized and only one circuit breaker is impacted. Option
B below is to be used when the main bus and incoming source
are not energized, and the substation is without power.
Option A)
Rack the selected circuit breaker to the TEST/DISCONNECT
position. Check the mechanical circuit breaker position
indicator before and after the racking operation to
assure the circuit breaker operation has been performed.
Unplug the secondary disconnect from the stationary
cubicle connection point. Close the circuit breaker door
and then install a padlock on the racking port cover to
prevent insertion of a racking mechanism, and padlock
the circuit breaker compartment door to prevent access
to the selected circuit breaker compartment. Once the
circuit breaker is racked to the Test/Disconnect position
and padlocks are secured, this circuit breaker cannot be
racked into the CONNECTED position and the compartment
cannot be accessed. Requires 2 distinct padlocks.
Option B)
Eliminate all sources of power to the substation. Rack the
circuit breaker out, disconnect the secondary coupler, then
remove the circuit breaker from the compartment. Once
the circuit breaker has been removed, padlock the shutters
in the closed position. This will prevent inserting a circuit
breaker into the CONNECTED position. Padlock or Tagout the
circuit breaker compartment door, to prevent insertion of a
circuit breaker or connection of the secondary disconnect
by unauthorized personnel. Require minimum of 1 padlock.
SecoGear – Installation, Operation and Maintenance Manual 52 of 56
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