Earthing and de-earthing the busbar system
139-2021.9 / 07
NXAIR M
139
Instruction label on door to low-voltage compartment:
In addition to these instructions, an instruction label on the door to the low-voltage compartment informs
about proper handling of the operating lever for the busbar earthing switch.
Fig. 236: Instruction label on door to low-voltage compartment
Preconditions
Busbar earthing switch in CLOSED position
Intended opening of the padlock released externally
Operating lever available
Electrician's ladder available as double-step ladder
Electromagnetic interlock (optional) deactivated
Fig. 237: Operating lever for operating the
busbar earthing switch
Procedure
Ensure that the intended manual switching operation has been released externally.
Make sure according to the panel number at the panel that the release for manual de-
earthing of exactly this panel is available.
Position the electrician's ladder correctly in front of the panel.