Siemens NXAIR M - Page 190

Key-operated interlocks
190 NXAIR M 139-2021.9 / 07
(1)
Cover, lifted
(2)
Screw thread for rotary button
(3)
Key release:
only when feeder earthing switch is
in CLOSED position
(4)
Key release:
only when feeder earthing switch is
in OPEN position
(5)
Key release:
only when withdrawable part is
racked to test position
Fig. 319: Example: Cover lifted
Operating the interlocks
Precondition
 High-voltage door closed
Procedure
Turn the rotary button counter-clockwise until it is possible to lift the cover.
To interlock an operating function, turn the associated key counter-clockwise as far as it will
go (that is 180°), and remove it.
Example: The feeder earthing switch is in CLOSED position (2). To interlock switching to
OPEN, turn the associated key (1) counter-clockwise as far as it will go, and remove it.
To release an interlocked function, insert the associated key, and turn clockwise as far as it
will go (that is 180°).
Example: The feeder earthing switch is in CLOSED position (2). To release switching to
OPEN, insert the associated key (1) as far as it will go, and turn clockwise.
Fig. 320: Example: Interlocking / releasing switching to OPEN
2