- Retired Electrical Engineer - Power Systems
First fuse blows. Switch gets stuck. Facility is single phasing.It still has overcurrent protection, but becomes a not so good disconnecting means, however following good safety procedures should have you checking for voltage first thing after opening a disconnect.
Boy aren't you glad we put in 'maintenance free' fuses.
If you don't bother to properly PM, then you should have a plan for 'unplanned' outages.