PowlVac
®
Electrically-Operated Ground and Test Device
IB-65060
8
The key lock K2 interlock is equipped with an electri-
cal switch element that electrically blocks a closing
command. The key lock K2 switch is in series with
the key lock K1 switch. Although the switch is not
required for operational sequencing logic, it is applied
for operational sequence protection redundancy.
The key lock K2 interlock is operable when key KB is
inserted. When the key lock K2 interlock is operated
with the locking bolt extended (by rotating key KC),
the ground and test device is electrically locked open,
key KB is retained, and key KC is released.
3) Key Lock K3 (Key KC)
The key lock K3 interlock is a single cylinder lock
(see Figures 1, d and Figure 5). When key lock K3
interlock is locked, the ground and test device is
prevented from being inserted into or removed from
the connected position of the circuit breaker compart-
ment.
When the ground and test device is in the discon-
nected position, the key lock K3 interlock prevents
the compartment-mounted racking device drive roller
from entering the corresponding racking slot on the
ground and test device, thereby preventing the
insertion of the ground and test device into the
connected position in the circuit breaker compart-
ment.
When the ground and test device is in the connected
position, the key lock K3 interlock captures the
compartment-mounted racking device drive roller in
the ground and test device racking slot, thus prevent-
ing the roller from further movement. This action
prevents the removal of the ground and test device
form the connected position.
With key KC inserted and the locking bolt retracted to
enable racking of the ground and test device into or
out of the connected position, key KC is retained.
4) Key Lock K4 (Keys KB and KD)
The key lock K4 interlock is a two cylinder lock used
to mechanically lock the ground and test device in
the CLOSED position (see Figure 1, v and Figure 6).
In the PowlVac
®
ground and test device design, the
locking bolt of the key lock K4 interlock cannot be
extended unless the ground and test device is in the
CLOSED position. The key lock K4 interlock is
equipped with an electrical switch element that
electrically blocks an opening command. The key
lock K4 switch is in series with the key lock K1
switch. Although the switch is not required for
operational sequencing logic, it is applied for opera-
tional sequence protection redundancy.
The key lock K4 interlock is operable only when key
KB is inserted and the ground and test device is
CLOSED. When the key lock K4 interlock is oper-
ated with the locking bolt extended, the tripping
function is electrically disabled, key KB is retained
and key KD is released.
5) Key Lock K5 (Key KD)
The key lock K5 interlock is a single cylinder lock.
The key lock K5 interlock is used to open and lock
the test port shutters (see Figure 1, f and Figure 7).
Key KD, which normally resides in the key lock K4
interlock, is available only when the ground and test
device is in the CLOSED and locked position. Key
KD is then inserted into key lock K5. With the
locking bolt retracted and the test port shutters
unlocked, key KD is retained. Key KD is removable
only when the locking bolt is extended in either of two
positions. One position is with the test port shutters
closed, and the other position is with the test probes
installed in the test ports and the shutter moved to
the test probe locking position.
D. CONTROL SELECTOR SWITCH
A control selector switch is mounted on the front of
the ground and test device. This selector switch
enables and disables the closing function and the
opening function (see Figure 1, i and Figure 8) of the
ground and test device.
The selector switch is a three position rotary switch
that operates in association with the remote OPEN/
CLOSE push-button control station. The snap-action
detented positions are OPEN, OFF, and CLOSE.
The selector switch is pad-lockable in the OFF
position.
E. INTERCHANGEABILITY
The PowlVac
®
ground and test devices are non-
interchangeable between the Con Edison and Cus-
tomer compartments. The coding plates will allow a
ground and test device labeled “Con Edison” into only
Con Edison incoming feeder compartments. Like-
wise, a ground and test device labeled “Customer”
can be inserted into only customer feeder compart-
ments.
