TylerB
Member
- Location
- San Jose, CA
Long time forum reader and admirer, first time poster!
Has anyone had an inspector ask if you have any paperwork stating that a transformer is compatible with the switch gear feeding it? If any of you are scratching your head, so am I.
The scenario (long story):
Typical commercial tenant improvement, relocate a couple of panels and install new transformers (new to comply with latest DOE requirements). The inspector wants to see the torque test of the feeders at the existing main service for the relocated equipment. During the inspection the inspector notices that the existing main service does not have an SCCR rating (because its old). Inspector will not do the torque test until we prove the switch gear itself is rated for the available fault current of the utility transformer. I point out that all of the breakers AIC ratings are higher than the AFC, but the inspector says no, the switch gear has to have an SCCR rating and it doesn't, so go figure it out. Great, so now we are 2 months later with a service change to install new switch gear. We do the change this weekend and and get the power back on to the building, but asks us to prove that the HPS brand transformers (112.5 kva 3ph 480-120/208) that we installed before the whole SCCR switchgear fiasco started are "compatible" with the new SQ D switch gear. Really!
I have no idea what she is asking for. There is no series rating of transformers to upstream protection, there is no SCCR or AIC ratings of transformers that I am aware of (other than the AFC at the secondaries that affects down stream equipment). I have absolutely no idea what the up stream switch gear or over current protection would have (other than the breaker rating/size) has to do with the transformer.
Any help on what she could possibly be talking about would be appreciated. I have been combing the NEC looking for requirements that I have not been called on before.
Has anyone had an inspector ask if you have any paperwork stating that a transformer is compatible with the switch gear feeding it? If any of you are scratching your head, so am I.
The scenario (long story):
Typical commercial tenant improvement, relocate a couple of panels and install new transformers (new to comply with latest DOE requirements). The inspector wants to see the torque test of the feeders at the existing main service for the relocated equipment. During the inspection the inspector notices that the existing main service does not have an SCCR rating (because its old). Inspector will not do the torque test until we prove the switch gear itself is rated for the available fault current of the utility transformer. I point out that all of the breakers AIC ratings are higher than the AFC, but the inspector says no, the switch gear has to have an SCCR rating and it doesn't, so go figure it out. Great, so now we are 2 months later with a service change to install new switch gear. We do the change this weekend and and get the power back on to the building, but asks us to prove that the HPS brand transformers (112.5 kva 3ph 480-120/208) that we installed before the whole SCCR switchgear fiasco started are "compatible" with the new SQ D switch gear. Really!
I have no idea what she is asking for. There is no series rating of transformers to upstream protection, there is no SCCR or AIC ratings of transformers that I am aware of (other than the AFC at the secondaries that affects down stream equipment). I have absolutely no idea what the up stream switch gear or over current protection would have (other than the breaker rating/size) has to do with the transformer.
Any help on what she could possibly be talking about would be appreciated. I have been combing the NEC looking for requirements that I have not been called on before.
