mstrlucky74
Senior Member
- Location
- NJ
Is it code that over a certain size that a xfrmr has to be floor mounted?
No code requirement. From a practical standpoint, if becomes more difficult to support larger units.
i think that 50 kva and above are not allowed above a ceiling...450.13
There is room to argue about whether a transformer can be mounted directly from a ceiling rather than a wall, floor or column based on 450.13, but I read it as permitting that type of mounting as long as it is still readily accessible (i.e. no ladder or scaffolding required, etc.) As long as it is readily accessible it can be mounted anywhere that properly supports it.i think that 50 kva and above are not allowed above a ceiling...450.13
In that case you do not have to worry about the 50 kVA limitation of 450.13(B).Im def not referring to above hung ceiling? Exposed!
You guys ever been to a Home Depot or Lowes?
The transformers are at the roof deck, clearly you need a ladder or lift to access them.
The only issue as they get larger is the weight and if the building structure is designed to support it.
Often they add steel to the trusses for us to hang them from.
And if the roof designers know this weight is going to be there they can design it to be able to handle it. 1000 pounds is not all that much weight for a roof, but the weight may need to be distributed over a certain area and not just all from one location.And those are quite often 112.5 KVA units that weight about 1000 pounds.
You guys ever been to a Home Depot or Lowes?
The transformers are at the roof deck, clearly you need a ladder or lift to access them.
The only issue as they get larger is the weight and if the building structure is designed to support it.
Often they add steel to the trusses for us to hang them from.
And if the roof designers know this weight is going to be there they can design it to be able to handle it.
There is room to argue about whether a transformer can be mounted directly from a ceiling rather than a wall, floor or column based on 450.13, but I read it as permitting that type of mounting as long as it is still readily accessible (i.e. no ladder or scaffolding required, etc.) As long as it is readily accessible it can be mounted anywhere that properly supports it.
But mounting, even attached to the wall, above a drop ceiling falls under the "hollow spaces not permanently closed in by structure" provision of (B), which limits the size to 50kva.
What are the advantages of hanging them?
I agree, we hang 75 Kva's all of the time often 10' or more above the floor. Regarding NYC there is nothing in the NYC Electrical code to prohibit hanging large transformers.