ponybetter
Member
- Location
- San Diego, CA in Good 'ol US of A
A client has two approximately 40 year old buildings fed by one 480V, 3000A service which is located in one and feeds 2000A to the other. The main switchgear and distributions immediately downstream are all 42K rated, whereas the utility letter shows a maximum short circuit fault current contribution of 52k 3-Phase and 53k Phase to ground.
Obviously new construction would stipulate that 65k gear be installed, but this is a pre-existing condition, and there is no documentation of what the utility contribution was at time of install. This electrical gear must have been rated to accommodate utility contribution at the time to get through plan check and inspection one would assume.
It was recommended that they replace with appropriately rated gear as theirs has not been maintained, is underrated, mismatched and an overall mess. The client is fine with this, but is questioning if it is a NEC code violation to have everything underrated, and if it would be "grandfathered in".
Any help in answering this would be appreciated.
Obviously new construction would stipulate that 65k gear be installed, but this is a pre-existing condition, and there is no documentation of what the utility contribution was at time of install. This electrical gear must have been rated to accommodate utility contribution at the time to get through plan check and inspection one would assume.
It was recommended that they replace with appropriately rated gear as theirs has not been maintained, is underrated, mismatched and an overall mess. The client is fine with this, but is questioning if it is a NEC code violation to have everything underrated, and if it would be "grandfathered in".
Any help in answering this would be appreciated.