# Install electrical panel to hollow masonary block



## Malywr (Jan 23, 2018)

Building is vibrating from machines 
I am looking for advice 
How do you install electrical equipment ( panel, box, disconnect....) on hollow block masonary wall 
I use tapcon, seismic wedge, expansion anchors and nothing seems to be working properly for long term 
Usually they become loose after year or two 
If manufacture recommend 4 anchors usually install 6-8

I started to use cement epoxy with those anchors and that seems to be better for bigger boxes ( no problem with 4x4 of 6x6 )


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## Kevin (Feb 14, 2017)

How about toggle bolts with locktite?


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## wiz1997 (Mar 30, 2021)

Toggle bolts as long as the block is actually hollow.
Sometimes the hollows are filled.
If the hollows don't fall where you need them, you may need to put up strut with the toggle bolts then fasten the box to the strut or drill holes in the box to match where the hollows are. 
Second method is usually my choice.
1/4" or larger toggle bolts and be certain the toggle opens.
Too short of a bolt and the toggle won't open correctly.
Then there have been times when we drilled completely through the block and used all thread rod with a square plate on the outside.


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## MotoGP1199 (Aug 11, 2014)

I use these style toggle bolts (Lowes caries them). they install and the plastic cinches tight to keep the toggle bolt in place until you mount the equipment. I have mounted 200+ lb equipment with no issues. I've never had anything fall off the wall. They sell them with 3/16" or 1/4" screws.

EDIT: Hilti makes(or used to make) this exact same style and were sold at home depot. Now the ones HD sells have a once piece plastic that breaks easily while installing and falls in the wall. They are twice as much money and complete crap. I don't go to lowes much so I just stock these in the van now.


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## Kevin (Feb 14, 2017)

MotoGP1199 said:


> I use these style toggle bolts (Lowes caries them). they install and the plastic cinches tight to keep the toggle bolt in place until you mount the equipment. I have mounted 200+ lb equipment with no issues. I've never had anything fall off the wall. They sell them with 3/16" or 1/4" screws.
> 
> EDIT: Hilti makes(or used to make) this exact same style and were sold at home depot. Now the ones HD sells have a once piece plastic that breaks easily while installing and falls in the wall. They are twice as much money and complete crap. I don't go to lowes much so I just stock these in the van now.
> 
> View attachment 155685


You can actually get them in larger sizes... 5/16, 3/8, and 1/2 as well.


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## John Valdes (May 17, 2007)

If its as bad as you describe you could use "all thread" all the way through with lock nuts and washers. Then you could tighten them when needed.
I have never done this with a panel and its only an "Idea".


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## Malywr (Jan 23, 2018)

Thank you all for advice 

In near future i will have to replace old panel ( arc flash requirements) mounted directly to wall hope i can install 7/8” strut so panel will not be to fat from the wall. Install Directly to wall would be perfect do to multiple rigid conduits coming up from floor and 1 of each sides
Opposite side of same wall is large electric panel 8’ tall and big transformer 6’ tall so that wall is not acceptable for rod go trough the wall 

I have to get ready for few options just in case. Job has to be done in one day


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## wiz1997 (Mar 30, 2021)

Done a few panel replacements with rigid conduit coming up out of the floor.
Knocked out the holes we needed for the conduits and set the box on the conduits.
Then we used a 1/2" hole saw to drill holes in the box where the anchors would be in the hollow of the block.
Once the pilot bit penetrated the back of the box , lean it out from the wall so you don't destroy your pilot bit or the hole saw.
Cover the conduit openings so your not dropping shavings into them.
(Ask me how I learned to do that)
Then used a rotor hammer to punch holes in the block.
Insert toggle bolts with a 1/4" x 1-1/4" fender washer.
Seemed easier than trying to lay out both the conduit holes and the anchoring holes at the same time.


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## Easy (Oct 18, 2017)

I don't think it should be a concern that machinery is vibrating unless it's so bad the the block wall is actually moving or vibrating. 

I like the Togglers that MotoGP posted a picture of.
If I’m reading the package correctly it says holds up to 1080 lbs. in concrete block. And with your rigid conduit supporting the panel from below what could go wrong. Maybe add some concrete adhesive to the back side of the panel if you really want to keep it in place.


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## Malywr (Jan 23, 2018)

Easy said:


> I don't think it should be a concern that machinery is vibrating unless it's so bad the the block wall is actually moving or vibrating.
> 
> I like the Togglers that MotoGP posted a picture of.
> If I’m reading the package correctly it says holds up to 1080 lbs. in concrete block. And with your rigid conduit supporting the panel from below what could go wrong. Maybe add some concrete adhesive to the back side of the panel if you really want to keep it in place.


Yes building is vibrating a lot 
Fire extinguishers anchors are coming out after one year. Maybe operators are helping too be hitting them with fork truck? But i seen other area anchors are out too. 

Thanks for advice i think you are correct conduit will help support from bottom 


Sent from my iPhone using Tapatalk


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## Flyingsod (Jul 11, 2013)

I know you’re prolly working on it now or done but I am wondering if the bolt is loosening from the anchor or the anchor is loosening from the wall?

Kevin’s suggestion of toggle bolts with locktite seems to be the best way to combat either. 

Sent from my iPhone using Tapatalk


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## Malywr (Jan 23, 2018)

Flyingsod said:


> I know you’re prolly working on it now or done but I am wondering if the bolt is loosening from the anchor or the anchor is loosening from the wall?
> 
> Kevin’s suggestion of toggle bolts with locktite seems to be the best way to combat either.
> 
> Sent from my iPhone using Tapatalk


I’m not working on it yet I’m waiting for permission when production stops for production go down but most of the time anchor got loose from concrete. Sometimes thread but anchored to solid concrete there is no problem hollow blocks for me they are always problem in this location


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## HertzHound (Jan 22, 2019)

A lot of jobs around here have seismic specs, even though we’re not on any fault line. The typical seismic spec is that Unistrut holding the panel has to be attached to the floor, wall and ceiling. So you would need Strut 90s on the top and bottom mounted to the ceiling and floor, as well as anchors in the wall. That outa hold it?


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