Can this 112.5 kVA transformer be in the attic space?

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fandi

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Hello All,
The transformer is 112.5kVA 480-208V Delta-Wye 3 phase. It's above the fan-ventilated ceiling. The OCPDs on the primary and secondary are from the readily accessible panels on the floor. I don't think it violates section 450.13(B) because this is an attic (not a hollow space) with light, fan, catwalk and about 6.5' vertical clearance. Will an accessible 'door' required for this transformer and if yes, what size is that door and will a permanent ladder is required?
Thanks a lot.
 
As long as your meeting the ventilation requirements of 450.9 and separation requirements of 450.21 (A), I don't think the is a problem with this installation. As far as a door goes, I'm not really sure what your asking? You do have to have access as required in 110.26 (C)(1), but a door isn't required.

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Jmccoll77 said:
As long as your meeting the ventilation requirements of 450.9 and separation requirements of 450.21 (A), I don't think the is a problem with this installation. As far as a door goes, I'm not really sure what your asking? You do have to have access as required in 110.26 (C)(1), but a door isn't required.

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Click to expand...

So an access is required per 110.26 (C)(1) but is a permanent ladder required?
 
fandi said:
Hello All,
The transformer is 112.5kVA 480-208V Delta-Wye 3 phase. It's above the fan-ventilated ceiling. The OCPDs on the primary and secondary are from the readily accessible panels on the floor. I don't think it violates section 450.13(B) because this is an attic (not a hollow space) with light, fan, catwalk and about 6.5' vertical clearance. Will an accessible 'door' required for this transformer and if yes, what size is that door and will a permanent ladder is required?
Thanks a lot.
Click to expand...

You note that the OCPD's for the secondary are from readily accessible panels on the floor; have you confirmed if you also meet 240.21 for the length of those secondary conductors (240.21(C)(2)), although I'm not sure what your facility is. During design, I always look to see what it would take to replace the transformer in the future as well so access, widths of doors, etc, are also things to take into account.
 
fandi said:
Hello All,
The transformer is 112.5kVA 480-208V Delta-Wye 3 phase. It's above the fan-ventilated ceiling. The OCPDs on the primary and secondary are from the readily accessible panels on the floor. I don't think it violates section 450.13(B) because this is an attic (not a hollow space) with light, fan, catwalk and about 6.5' vertical clearance. Will an accessible 'door' required for this transformer and if yes, what size is that door and will a permanent ladder is required?
Thanks a lot.
Click to expand...
Sounds like it meets intent of 450.13(B) more so then if it were above a suspended ceiling.

If this is an attic and apparently you are in LA area - what kind of ambient temp do you expect in this attic is something to consider and if the transformer can take that while loaded.
 
Coppersmith said:
One nice thing about this forum is people generally only answer if they have something useful or funny to contribute. Or would rather read thru a bunch of useless answers?
Click to expand...

I'll respond....

If it's already up there rockin and rollin, why would you want to disturb an already beautiful scenario? :)


JAP>
 
tw1156 said:
You note that the OCPD's for the secondary are from readily accessible panels on the floor; have you confirmed if you also meet 240.21 for the length of those secondary conductors (240.21(C)(2)), although I'm not sure what your facility is. During design, I always look to see what it would take to replace the transformer in the future as well so access, widths of doors, etc, are also things to take into account.
Click to expand...
The length of the secondary conductors is more than 10ft but less than 25ft and it complies with 240.21(C)(6).
 
I just wasted thirty minutes of my time reading thru this thread most answers have nothing to do with OP question but are being funny. I should have bought milk and took my dog for a walk within that time. What can you do? Oh well such is life.

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To answer your questions regarding the door and ladder, I think a little Common Sense may come into play here... If this transformer ever fails and has to be taken out, you do not want to have to cut the ceiling open to remove it, so it stands to reason the door /hatch needs to be at least size of the transformer. As far as a ladder goes, I do not think one is required, and a ladder that is built in to the hatch will be in the way of getting a new transformer in or out anyway.

The last custom home we did had two HVAC units in the attic... The hatch was big enough that the units could come through it.

Personally, I find that any type of equipment located in attic is an extremely poor design choice. I hope there is a crane and gantry up there to move the thing should the need arise.
 
JFletcher said:
To answer your questions regarding the door and ladder, I think a little Common Sense may come into play here... If this transformer ever fails and has to be taken out, you do not want to have to cut the ceiling open to remove it, so it stands to reason the door /hatch needs to be at least size of the transformer. As far as a ladder goes, I do not think one is required, and a ladder that is built in to the hatch will be in the way of getting a new transformer in or out anyway.

The last custom home we did had two HVAC units in the attic... The hatch was big enough that the units could come through it.

Personally, I find that any type of equipment located in attic is an extremely poor design choice. I hope there is a crane and gantry up there to move the thing should the need arise.
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But floor space is too valuable for necessary things like HVAC equipment.:blink:
 
JFletcher said:
To answer your questions regarding the door and ladder, I think a little Common Sense may come into play here... If this transformer ever fails and has to be taken out, you do not want to have to cut the ceiling open to remove it, so it stands to reason the door /hatch needs to be at least size of the transformer. As far as a ladder goes, I do not think one is required, and a ladder that is built in to the hatch will be in the way of getting a new transformer in or out anyway.

The last custom home we did had two HVAC units in the attic... The hatch was big enough that the units could come through it.

Personally, I find that any type of equipment located in attic is an extremely poor design choice. I hope there is a crane and gantry up there to move the thing should the need arise.
Click to expand...
Thanks for your thoughts.
 
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