abb
SafeLink
SF
6
Insulated Ring Main Unit
Installation and Operating Instructions
SLMIO ver 2.12
ABB Ltd, Switchgear Division, Auckland, New Zealand
7
status,
earth
switch operation is not possible (the switch must first be returned to
off
).
Likewise, from
earthed
status the
main
switch operation is not possible.
After selecting the desired operation insert the handle and rotate in the direction
indicated by the symbols. For instance, to switch from
off
to
on
the handle is rotated
clockwise. About 60° rotation is required for switch operation; internal stops provide
limits to the movement. The operating handle has been designed to give a delay
between operations either clockwise or anti-clockwise.
Figure 6: Front of SafeLink unit showing the mimic diagram and switches in
(from left to right) the
off, on,
and
earth
positions.
The status of each switch is indicated by an active mimic diagram that changes to reflect
the state of the switch. Black lines show that a switch is open, while white lines show
the switch is closed. In addition, the status of each switch is indicated by a symbol (O, I
or
) for
off
,
on
and
earth
respectively.
Interlocks are provided to ensure that operators can perform switching operations only
in the correct sequence; and to ensure that access to cable terminations and other high
voltage areas are prevented when voltage is present.
Only when the switch has been earthed and the selector returned to the blocked position
can the associated cable box cover be removed. Once the cover is removed, the
interlock prevents the switch being closed until the cover is replaced. While the covers
are removed, the switch can only be moved from
earth
to
off
, this allows for cable
testing to be carried out. See Section 2.6 on page 11 for further details.