2 questions regarding transformer locations and electrical room access

[Gray_Smith]

Hey guys,
my first post here and I'm a learning electrical designer without much code experience. I was asked a question about how far a main entrance dry type transforer needs to be mounted away from a school building...I was told it was 10' but I need to verify this. According to the code book under section 450.21 its only a foot...but this is a service entrance stepping down to 480/277 3 ph feeding to switchgear one at 1200amps the other at 1600 amps. Lastly for this same building is a lockable room sufficient for location of the main entrance switchgear or does it need to be located within a fenced area where we are also locating our chiller equipment. the code book under section 110 only says a separate room is needed. I'm usually under the direction of our engineer and he is currently on vacation so this is why i'm asking here.

Thanks
Gray Smith

 

[steve66]

I wouldn't expect a main entrance transformer to be a dry type. It will more likely be oil filled.

If it is the utility companies transformer, they may have their own requirements about its clearance from the building. This is to make sure they have enough room to service or replace the transfromer.

I would think a lockable room would suffice for the switchgear. I'm not sure what part of 110 you think requires a separate lockable room, but a lockable room sounds prudent for a school. I don't see why the electrical switchgear couldn't share a room with other mechanical equipment though, as long as the required working space and equipment space is kept clear around the switchgear.

Steve