We are replacing an obsolete switchgear (main fuse switch & CB distribution) with new. The existing main fuse switch is 1200A. The new gear will be 2000A buss with a 2000A main fuse switch fused at 1200A. This will allow capacity for any future expansion.
Here is my question. The incoming service feeder consists of 3-500 MCM. This was OK when the building was built 30+ years ago. Since 3-500's are only good for 1140 amps, our new main fuse switch with 1200A fuses will not work, 240.4,C.
Right? Or since this is existing conditions and we are not changing the connected load, just updating the gear, would this be accepted.
The budget will not allow changing the service at this time. If and when loads are added that would result in increasing the main switch fuse size, then the service feeder would be changed at that time.
Here is my question. The incoming service feeder consists of 3-500 MCM. This was OK when the building was built 30+ years ago. Since 3-500's are only good for 1140 amps, our new main fuse switch with 1200A fuses will not work, 240.4,C.
Right? Or since this is existing conditions and we are not changing the connected load, just updating the gear, would this be accepted.
The budget will not allow changing the service at this time. If and when loads are added that would result in increasing the main switch fuse size, then the service feeder would be changed at that time.