# Hanging transformers



## 14471 (Aug 20, 2010)

Greetings,
Does anyone know where I find drawings which show mounting details for hanging transformers from concrete slabs? I'm doing a few small transformers 15 - 30 kva, all under 300 pounds. I intend to use 3/8" threaded rod with lead anchors (old school), run down to deep strut. I know it's adequate, but the municipality is asking for a detailed drawing of the work. I've Googled to no avail and also went to manufacturers websites but am having no luck.
Thanks for the input
MrCoonass


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## macmikeman (Jan 23, 2007)

When it is just concrete to hold the transformers, I secure strut to the upper slab with multiple anchors and then run rods down from that. If that is exactly what you were trying to say then you should be good to go. 

You're best bet - Try googling "transformer mounting detail"


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## CoolWill (Jan 5, 2019)

Get a nice straight edge and pen and draw it.


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## Helmut (May 7, 2014)

I would have a engineer spec out supports for the loads you intend to hang.

FWIW


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## Tonedeaf (Nov 26, 2012)

I suspect the municipality is worried about the led anchors in the concrete ceiling......I would get my anchors from hilti and ask them to specify and give you documentation. They have an engineering department.


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## flyboy (Jun 13, 2011)

These are better then lead anchors.


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## Jlarson (Jun 28, 2009)

I doubt there is a fire department/ fire marshal in the country that is gonna allow lead anchors for overhead. 



1/2" anchors and rod are more typical for small transformer hangers too.


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## splatz (May 23, 2015)

Are the lead anchors rated for overhead support? 

To dot all the i's and cross all the t's, you need to know the load limits for the fasteners you're using, and usually those ratings are based on the concrete - the PSI rating / hollow core etc. 

Usually it's worked out better for me to hang strut from bar joist to bar joist or beam to beam, makes it really easy to have every fastener strong enough to support the entire load. 

If you have to - as @macmikeman says strap strut to the ceiling with a lot of fasteners and it's easier to overbuild, rather than four fasteners hanging four you can have 12 fasteners hanging two struts and those struts hanging the four rods.


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## Southeast Power (Jan 18, 2009)

FWIW, a 1/2" sleeve anchor will typically have the same thread as a 3/8" rod coupling.


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## 99cents (Aug 20, 2012)

Scan before you drill.


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## B-Nabs (Jun 4, 2014)

I would use 5" long 1/2" wedge anchors, 1/2" rod couplings and 1/2" rod down to deep strut. And as 99 says, scan before you drill that deep. 

Sent from my SM-G920W8 using Tapatalk


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## gottspeed (Mar 8, 2010)

Flush shells are used all the time for this. Set them with your hilti and an old 1/4” bit.


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## Southeast Power (Jan 18, 2009)

14471 said:


> Greetings,
> Does anyone know where I find drawings which show mounting details for hanging transformers from concrete slabs? I'm doing a few small transformers 15 - 30 kva, all under 300 pounds. I intend to use 3/8" threaded rod with lead anchors (old school), run down to deep strut. I know it's adequate, but the municipality is asking for a detailed drawing of the work. I've Googled to no avail and also went to manufacturers websites but am having no luck.
> Thanks for the input
> MrCoonass


The problem is not the anchor but someone signing off on the strength of the concrete.
We haven't used lead anchors in decades, there are just way too many other choices.
300 lbs Divided by 4 isn't much weight on a 1/2" sleeve anchor.


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## SWDweller (Dec 9, 2020)

There are tons of concrete fasenators out there. ( intentional ) We all have favorites, and they work well. When it comes to transfromers in the air I am a fan of going through the wall and using a plate on the outside. Yes ugly, guarnteed not to fail unless there is a flash over event in the building.


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