When replacing the main, tie and feeder breakers (all draw out CBs) in MTM switchgear with new, same size & retrofitted CB, one CB at a time. Because these are draw out CBs, I assume the electrican wont need to shut down power to the switchgear for this task, correct?
MTM switchgear
- Thread starter anbm
- Start date
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
One of the most risky things to do is to rack in/out breakers onto a live bus, especially with old or poorly maintained racking mechanisms.
Last edited:
zbang
Senior Member
- Location
- Roughly 5346 miles from Earls Court
Might not need a shutdown, but would then need one of those breaker-racking devices (e.g. https://safe-t-rack.com/) and some good PPE. Would also need a Plan B if something goes up the wall, like when a new breaker doesn't fully engage the bus.
Or, just schedule a shutdown for the replacement and get in all the other deferred maintenance at once
. Planned shutdowns are often cheaper than a failure would be.
Or, just schedule a shutdown for the replacement and get in all the other deferred maintenance at once
. Planned shutdowns are often cheaper than a failure would be.