suspended transformer

MBLES

Senior Member
prints show us needing to hang a transfomer over head. the ceiling is cement and doesnt have any bar joist or framing. i guess they want us to use some type of anchor does anyone have any suggestions for this application??
 

iwire

Moderator
Staff member
Location
Massachusetts
+999999

That's not an electrician's job. That's an engineer's job. Make sure the design has a wet seal for your files. (assuming this is not for a doorbell:) )
This is why I asked the weight.

200 pounds or less I would be fine on my own, over that I want an engineer.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
We hang them, usually up to 75 kva which is about 800 pounds. For us no need for an engineer just use 1/2" rod with the proper anchors and strut. If you can get one to sign off that's great.
 

JFletcher

Senior Member
Location
Williamsburg, VA
prints show us needing to hang a transfomer over head. the ceiling is cement and doesnt have any bar joist or framing. i guess they want us to use some type of anchor does anyone have any suggestions for this application??
What kind of cement; pre-cast hollow core, rebar/slab, post tension concrete? As others wrote, you ought to have an engineer sign off on a project like this
 

iwire

Moderator
Staff member
Location
Massachusetts
We hang them, usually up to 75 kva which is about 800 pounds. For us no need for an engineer just use 1/2" rod with the proper anchors and strut. If you can get one to sign off that's great.
We / I used too but no longer, now it is engineered and often mounts provided by the steel contractors with us lifting them into place.
 

Tony S

Senior Member
prints show us needing to hang a transfomer over head. the ceiling is cement and doesnt have any bar joist or framing. i guess they want us to use some type of anchor does anyone have any suggestions for this application??
Advice? Don’t do it.

I certainly wouldn’t take responsibility for the structural integrity.
 

Strathead

Senior Member
We hang them, usually up to 75 kva which is about 800 pounds. For us no need for an engineer just use 1/2" rod with the proper anchors and strut. If you can get one to sign off that's great.
I am with you and for the doubters

https://www.us.hilti.com/medias/sys...chnical_information_ASSET_DOC_LOC_1543428.pdf

is a link to the pullout strength of Hilti anchors, you could easily use even 4- 1/4" anchors in only 2000 PSI concrete, and still mount a 2000 pound transformer with a safety factor of 4.

I would use 3/8 without hesitation and 1/2" would be the overkill you may want to use if you have a cautious customer who wants to pay.
 

iwire

Moderator
Staff member
Location
Massachusetts
I am with you and for the doubters

https://www.us.hilti.com/medias/sys...chnical_information_ASSET_DOC_LOC_1543428.pdf

is a link to the pullout strength of Hilti anchors, you could easily use even 4- 1/4" anchors in only 2000 PSI concrete, and still mount a 2000 pound transformer with a safety factor of 4.

I would use 3/8 without hesitation and 1/2" would be the overkill you may want to use if you have a cautious customer who wants to pay.
Dude, it is not that we cannot do it. It is that we and in my case the company I work for do not want to assume the liability for it.:cool:

What is the up side of taking this on yourself when it can be taken by someone else?
 

Strathead

Senior Member
Dude, it is not that we cannot do it. It is that we and in my case the company I work for do not want to assume the liability for it.:cool:

What is the up side of taking this on yourself when it can be taken by someone else?
That totally depends on all the other factors. Many times there is no upside, other times there is. Given the table there is so very little risk of pull out that the liability is minimal. I am assuming you don't get engineering approval to install a conduit rack for example, or to secure a motor starter to a wall. I fully understand your concern, I just think it is no likely to be and issue.
 

mgookin

Senior Member
Location
Fort Myers, FL
prints show us needing to hang a transfomer over head. the ceiling is cement and doesnt have any bar joist or framing. i guess they want us to use some type of anchor does anyone have any suggestions for this application??
You can call the guy whose name is on the plans and ask him for the detail.
 

iwire

Moderator
Staff member
Location
Massachusetts
That totally depends on all the other factors. Many times there is no upside, other times there is. Given the table there is so very little risk of pull out that the liability is minimal. I am assuming you don't get engineering approval to install a conduit rack for example, or to secure a motor starter to a wall. I fully understand your concern, I just think it is no likely to be and issue.
I agree it can depend on a lot of things. I would be much more comfortable with steel than concrete.

I also find as I get older I worry much more about what could happen. Maybe I watch to many internet accident videos. :D
 

Strathead

Senior Member
I agree it can depend on a lot of things. I would be much more comfortable with steel than concrete.

I also find as I get older I worry much more about what could happen. Maybe I watch to many internet accident videos. :D
Yes, I find that I need Xanac nowadays when it used to roll off. Especially when I win a job and start to wonder what I missed.
 

ron

Senior Member
You can call the guy whose name is on the plans and ask him for the detail.
I can imagine the arm wrestling match. The EE gets an RFI, and then sends it to the Structural Engineer, then the Structural Engineer says that he wants a change order to provide the design. :happyno:

Lots of fun and delays.
 

mgookin

Senior Member
Location
Fort Myers, FL
I'ts the design professional's duty to provide sufficient detail to build it. It's not your fault they failed to provide the detail. If you never ask, they're going to keep doing it to you.
And the EE very well may already have standard details. Engineers are allowed to cross into other disciplines which they are proficient in. I'd think an EE is proficient in hanging a tranny, especially if he wrote the spec.
 

rippledipple

Member
Location
New Jersey
Occupation
Electrical contractor
anchors

anchors

I'ts the design professional's duty to provide sufficient detail to build it. It's not your fault they failed to provide the detail. If you never ask, they're going to keep doing it to you.
And the EE very well may already have standard details. Engineers are allowed to cross into other disciplines which they are proficient in. I'd think an EE is proficient in hanging a tranny, especially if he wrote the spec.
I would go through the roof, anchors pull out,muck it really good. Rather have a small leak than that thing falling on someone!!!!!!!
 
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