10.3.3
Closing the make-proof grounding switch
The converter is optionally equipped with make-proof grounding switches (N44 or N45).
The make-proof grounding switches can be closed when the medium voltage doors or panels
have been closed and the following prerequisites are fulfilled:
• The DC link voltage must be de-energized.
• The EMERGENCY-OFF switch on the cabinet unit must be activated.
• The key-operated switch on the converter must be set to the OFF position.
• A delay time of 10 minutes must have expired.
If the auxiliary voltage fails completely, the make-proof grounding switch cannot be closed.
When provided, the medium voltage doors are secured by the electrical door magnet system and
can be opened only after the make-proof grounding switch is closed.
Type 6SR5 Air-Cooled
Operating Instructions, AK, A5E39390112
10.3 VFD Power Down and Door Access
Maintenance
65