# Suspended Transformer



## nick.pei

Need to suspend a 112.5KVA transformer weighing about 710lbs from building structure. Thinking 4 beam clamps and 1/2" threaded rod with 2 1/4" thick angles steel to bolt transformer onto? Would this be strong enough? Roof/ceiling is about 19' high and t-bar ceiling will be at 11-1/2'


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## denny3992

Uhh illegal to install one that big above drop ceiling...


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## nick.pei

denny3992 said:


> Uhh illegal to install one that big above drop ceiling...


In Canada?


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## denny3992

Heres the code ref


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## denny3992

nick.pei said:


> In Canada?


Didnt know u were a canadien ehh


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## nick.pei

Nothing that I've seen in the CEC and it's engineered plans. Just want to know best method to go about it?


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## ponyboy

I hang transformers that big every day. If it's bar joists you're hanging from make sure to attach to the top and not the bottom. 

Also I always avoid hanging them freely like that. I'd put it on a column or a wall if possible


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## SteveBayshore

I wouldn't trust cast beam clamps. Make sure to check the load rating of what you decide to use, don't just use convenient sizes.


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## nick.pei

Currently have transformer sitting on the deck of a scissor lift and tomorrow need to readjust the chainfall. We have 1/2" threaded rod through the center of bottom part of joist with solid deep unistrut T'd across the opening. A big washer and double nutted on the top. Not sure if it's the best way to do it but we were told it will hold the weight no problem. I'll try to get some pictures tomorrow to show exact setup


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## five.five-six

nick.pei said:


> it's engineered plans.


They don't specify how to suspend it?


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## nick.pei

Nope. You'd think they should though.


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## Southeast Power

nick.pei said:


> Need to suspend a 112.5KVA transformer weighing about 710lbs from building structure. Thinking 4 beam clamps and 1/2" threaded rod with 2 1/4" thick angles steel to bolt transformer onto? Would this be strong enough? Roof/ceiling is about 19' high and t-bar ceiling will be at 11-1/2'


Any holes in the T bar??


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## walkerj

nick.pei said:


> Nope. You'd think they should though.


It probably says 'as required'


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## five.five-six

nick.pei said:


> Nope. You'd think they should though.


I'd like something like that on the stamped prints, in case it falls you'd be clear.


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## Southeast Power

nick.pei said:


> Currently have transformer sitting on the deck of a scissor lift and tomorrow need to readjust the chainfall. We have 1/2" threaded rod through the center of bottom part of joist with solid deep unistrut T'd across the opening. A big washer and double nutted on the top. Not sure if it's the best way to do it but we were told it will hold the weight no problem. I'll try to get some pictures tomorrow to show exact setup


Spread the weight out over three of the bar joists it you think the weight will be a problem


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## nick.pei

jrannis said:


> Any holes in the T bar??


None yet. As long as it doesn't drop down to the ground. The T-bar ceiling is going to hide the transformer!


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## nick.pei

She's hung now. Need to brace it to wall to keep it steady next


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## daveEM

700 pounds there? Trusses must be super oversized eh?


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## local134gt

nick.pei said:


> She's hung now. Need to brace it to wall to keep it steady next


Is that legal? Around here we are only allowed to attach to the top of the bar joists.


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## Pete m.

local134gt said:


> Is that legal? Around here we are only allowed to attach to the top of the bar joists.


I'm obviously not a structural engineer but I have always understood to hang heavy loads from the top chord of a bar joist. For example look at sprinkler mains (and branch piping for that matter..) they are almost always supported from the top chord.

The other concern could be point loading on the bar joist. Typically, RTU's have additional support members added to the bar joists to distribute the weight.

Pete


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## denny3992

I think i woulda tack welded those nuts on the rod... Wouldnt want that vibratiion to back those nuts out... Yikes


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## drumnut08

denny3992 said:


> I think i woulda tack welded those nuts on the rod... Wouldnt want that vibratiion to back those nuts out... Yikes


either that or double nutted tightened against themselves top and bottom , or Ny-lock nuts ?


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## drumnut08

Pete m. said:


> I'm obviously not a structural engineer but I have always understood to hang heavy loads from the top chord of a bar joist. For example look at sprinkler mains (and branch piping for that matter..) they are almost always supported from the top chord. The other concern could be point loading on the bar joist. Typically, RTU's have additional support members added to the bar joists to distribute the weight. Pete


it should absolutely be hung from the top chord for the most strength . The fact that this thing is almost at the end of the joist tells me there are vertical columns on the wall or on the other side of it , so you'll end up with way less deflection here than say in the middle of the span . At least now there's a nice heated air space above the ceiling grid , lol ! Aside from not being a good idea maintenance wise , it's illegal here now .


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## denny3992

drumnut08 said:


> it should absolutely be hung from the top chord for the most strength . The fact that this thing is almost at the end of the joist tells me there are vertical columns on the wall or on the other side of it , so you'll end up with way less deflection here than say in the middle of the span . At least now there's a nice heated air space above the ceiling grid , lol ! Aside from not being a good idea maintenance wise , it's illegal here now .


Ive hung 10kva transf above ceilings, and that alone would kill someone had it come down! 

We have to support fluorescent layins in case of hurricanes/ ceiling failure but can mount a #100 lb transformer above a ceiling.... Smh


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## 10492

Thin strut above the joist, below roof decking.
Thick strut under the joist.
Thick strut to mount the transformer.
1/2" allthread, cone nuts in the thin strut, 3/8" square washers on both sides of thick strut, and double nut everything.

FWIW....


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## drumnut08

denny3992 said:


> Ive hung 10kva transf above ceilings, and that alone would kill someone had it come down! We have to support fluorescent layins in case of hurricanes/ ceiling failure but can mount a #100 lb transformer above a ceiling.... Smh


 I worked on a school years ago that had at least 6 big transformers above a drop ceiling . We actually spanned the block walls with I beams and made a platform from there . It was the dumbest thing I'd ever seen and after the ductwork went in , damn near inaccessible , lol ! It was engineered that way and the inspector passed it ! This was before the code change obviously ! I'm sure those things smoked long ago . Theres not exactly cool air circulating above ceilings , lol !


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## nick.pei

It's solid but we are going to have it beefed up. It was suggested that rods be welded in place where the load points are vertically between the top and bottom angle iron. Everything is double nutted and loc-tite applied to nuts to keep from working themselves off. 

The plans say to mount transformer with rod (typ). 

No worries of hurricanes here but snowload would be an issue with having a flat roof

This is for a 400A service for a unit in a new strip mall. Cheaper for the building owner to just run the 600v to each unit for rooftop units, and have each tenant supply their own transformer.


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## Chrisibew440

I'd have steel welded up and hung from the top joists


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## jza

All this fuss over 700 pounds.


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## Honestly

Great thread- this is why I come here. Your personalities all suck, but good info :laughing:


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## WhitehouseRT

All liability on my shoulders.... I would use some vertical strut and rod stiffeners...


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