18
S&C Instruction Sheet 775-510
Optional Disconnect Operation
The optional disconnects for the Scada-Mate SD switch
are single-phase disconnects. Each disconnect is operated
separately from the other. Unless specifi ed otherwise, the
disconnects will be pre-installed to the switch terminal
pads. See Figure 16 on page 17.
Users will need to implement operating procedures to
ensure all three disconnects are closed before the switch is
closed and all disconnects are only opened after the switch
has been opened. The disconnects mechanically interlock
with the switch, preventing the closing of the switch unless
all three disconnects are closed. The disconnects are
blocked from opening when the switch is closed. Even with
this feature, users must establish operating procedures to
ensure all disconnects are open when the switch is open
before a true three-phase “visible-break” is attained.
To manipulate the disconnect operating ring, follow the
procedure below using a conventional insulated hookstick
or S&C Universal Pole and Pole Extension (if required) fit-
ted with a heavy-duty hook-tool such as the S&C Substation
Prong or equivalent.
STEP 23.
Verify the switch is open by checking the OPEN/
CLOSE indicator on the end of the switch. See
Figure 17. Place the LOCAL/ REMOTE switch
inside the control unit in the
Local
position
before operating the disconnect. Refer to the
instruction sheet furnished with the control
unit. Now the switch can only be operated
locally.
STEP 24.
Open the disconnect by pulling down on the
operating ring. See Figure 18. The latch will
release and the disconnect can be pulled open.
Disengage the hookstick from the operating ring.
Repeat with the remaining two disconnects.
The switch is interlocked in the
Open
state while the disconnects are in the fully
Open
position.
Figure 17. The Scada-Mate SD switch in the Open position.
Figure 18. Open the disconnect by pulling the operating ring
downward with a hookstick.
Operation—For Switches with Power Operator
Operating
ring
Indicator in
Open position
Indicator in
Open position
Pull operating
ring downward
Hookstick
