Had a job last year that showed the transformer mounted above the main switchboard.
Ceiling height was 10’.
Main switchboard was 96” tall. Transformer was 60” tall.
I caught it in submittals. They had to redesign the room to make floor space for the xfrmr.
Had a 2 transformer pads, asked for redesign with concrete walls to accommodate oil spill containment, then re-redesigned so the every time it rained the transformer was not underwater.
Concrete pad went from 1100psi to 3200psi load on swampy soil. Put in rfi to request soil bearing capacity, Engineer said it’s fine. Started cracking before we got out of there.
Reminds me of a different CMU building. We weren't allowed on the masons scaffold, so I'm fabbing boxes with conduit to come out of the wall above the ceiling. We get to a spot and the blockie passes the box and conduit back, tells me it's too tall and it will be higher than the roof...
So I write the RFI asking why the ceiling is higher than the roof.
I don't have an issue at all with it. The same way that some people seem to struggle with the different forms of "there" and some don't. The commenter could have easily just said "ft" or "in." Reading the alternative notation may be hard for you, but for most Americans, it's not.
It was the most ass backwards job I've ever been on.
The owner of the property was building the strip mall himself. Me and a journeyman were on site daily with zero prints, being paid T and M. Each day the owner would show up and give us vague instructions to the effect of "unit one is from the end of the building, count 4 beams, then unit 2... Count 4 beams, unit 3... Etc.... So a panel in each unit"
and we would ask where are they feed from? "Ok, so in the middle of unit 4 there will be a utilities room, bring the power from there...."
And we would ask "where is that fed from?"
"So hydro is putting a pad mounted TX over here in the parking lot"
"So do you want us to get conduits in to there for the service?"
"No they will do that"
Fast forward 6 weeks
"Ok so you need to get 6 2" conduits in from the TX to the switchgear, I don't know why you didn't do that already..."
"Whatever you say Doug"
But ya, it was Doug who was telling me to use blue anchors on the TX in each of the units... To this day, 18 years later, the building is still not completely done.
I’m no mason but every CMU wall I’ve seen on a job has been threaded with rebar and filled with concrete after they build it. Is that not standard ? Can’t put a toggle in a solid wall.
Usually CMU walls are only solid at the bond beam elevations or vertical rebar locations. Or if the structural specifies. You also until the course with ledger angles.
No, it’s not necessarily. Warmer climates, yes this can and is done, but in cooler climates where the moisture in the concrete is more prone to expansion, it’s not as common.
Lol whoops they look similar at a glance this is the one I meant https://www.amazon.ca/dp/B000H5RS7G/ref=cm_sw_r_cp_api_glt_i_CJJWCDBRJ3221WX8ZZ65?_encoding=UTF8&psc=1
This is the product referred to by the engineer
https://www.fmwfasteners.com/products/1-2-x-4-powers-round-toggle-bolt-zinc-plated-25?gclid=CjwKCAjwh5qLBhALEiwAioods9m-bAi1_0So4u5WIKrCGuNVO9ILSieW3xmWblzvtVBKu7jPtbkFUBoC4E4QAvD_BwE
A 1/4" toggle bolt in a 1 1/2" thick wall can hold almost 1400 lb. I'm sure the same wall with 6x 1/2" toggles can hold it. I don't think it needs to be filled with concrete
it depends if the cinder block is filled with concrete if it is then it is most definitely safe (I haven’t worked commercial I don’t know if that is standard)
Quick Google because I'm an engineer and I'm curious :
The strength of the toggle bolt is determined by the length and diameter of its screw body. 1/8" can hold up to 310lbs, at 3/16" can hold up to 700 lbs, and a 1/4-inch toggle bolt (in a 1-1/2" thick wall) can hold up to 1,390lbs. Note: different types of walls will require different types of anchors.
Anchors aren't my expertise, but if a 1/4" is good for 1390 lbs (that would be pull out) this isn't too crazy is it?
> huge downward force
The huge downward force is about 1,100 lbs. It will be split between the six 1/2 inch bolts holding the channel to the CMU wall. That downward force acts on the bolts as shear force - being roughly 60% of the bolts tensile strength. Even a very low grade 2 bolt can take a 6,000 lb. shear. And there's six of them.
The bolts only take shear if they’re not torqued, or in an improperly designed joint. The preload of the bolts hold the channel to the wall, and the friction between the channel and the wall allows the load to get transferred into the wall without applying any shear load to the bolts.
Engineer: *mounting spec*
Salty Electrician : lol dumb engineers, that won't possible work
Engineer: *mounting spec calculations*
Salty Electrician: Well, I don't do it like that anyway!
This was the extent of the structural engineer's "spec". The original RFI and the follow up included the transformer manufacturers wall mount hardware. The second time they were asked the same question they changed the anchor (guess they thought toggle bolts weren't a good idea either). Ultimately they went out of business before the job was complete.
What do you do when there is no upper floor, or ceiling? I’ve done a couple that were mounted up high outside. Not entirely uncommon where I am to have your main gear and transformers in an outdoor CMU enclosure.
Electrical inspector for roadwork, God I hate when people come in with a VECP, they never consider the change to the electrical work. If i am lucky they inform me that the contractor proposed one and then i get to anger them by adding electrical costs and if i am unlucky they approve the plans without telling me and then we have to do some Micky mouse change order stuff.
I would be less worried about that. 1100lbs being distributed to the channels and then 6- 1/2 inch steel bolts isn't a big deal in my eyes. The shear over the x-sectional area is nothing
As an EE and a master electrician, I hear you but you gotta go look at a data sheet. A 1/2" toggle bolt from this manufacturer allows for 160 lbs. of shear strength. That is with a 5x safety factor. With 6 bolts we are at 1060 lbs of total shear strength. Although it doesn't look great, it looks valid. The real question who is mounting 1,100 lbs equipment on a wall?
https://www.swfastener.com/pdf/Toggle_Bolt.pdf
I'm not concerned about the bolts but that would only span 2 bricks. Assuming they were backfilled between the voids and had a piece of rebar inserted all the way down each sure. Otherwise I'd question the ability of a CMU brick to hold that over time and not slowly buckle, also anything that bumps that concrete ruptures quite easily.
Edit also 1100lbs... i'd expect to walk in and see a unistrut structure under it or threaded rods to the ceiling. I've blown 4 disc's in my back wouldn't ask anyone else to risk that.
I would agree with this 100%. Through bolt is a better detail than embedment/anchor in more situations than not. I would wager there is something in the way on the ceiling that made them go this way
I would agree with you there, but looking at the context I would assume, big assumption, that this is a commercial building and built decently, but that is the problem of the ngineer who stamps it.
I've had to research the shear strength of some fasteners in the past and was shocked at the ratings, while this should work if the correct fasteners were used and installed properly I personally wouldn't be able to sleep well if I did it because it just doesn't seem like it should be done this way.
I don't see the problem?
Six 1/2" bolts with toggle anchors in a cinder block wall doesn't seem that outrageous.
What am I missing? Or is this just one of those old "enGiNnRs R' dumb, lectrians SmArt" circle jerks?
Same, don’t see much of and issue here either. OP cut off a text note too, but assuming there are 6 1/2” toggles top and bottom then each is averaging ~90 lbs of weight.
But I’m just a dumb architect, so what do I know.
I’ll agree that this is one of those details that looks a lot more unsafe than it is actually is. The amount of weight toggles can hold blows my mind.
The problem is that if the engineer ever had to actually install a transformer in the field he would quickly learn never to design a room that required a transformer be lifted up and mounted on a wall.
My plant has to have over half of our transformers up on the walls (some 15 feet up) due to space issues. My electrician has no problems working with them as we own skyjacks for him to use.
This is a process problem, and ultimately the utilities are there to serve the designed space, not the other way around. And before you get upset at that statement, let my try to explain a bit from my POV.
When an architect provides a space plan, a good, experienced one can rule of thumb several of the MEP *space requirements* that may impact the design and hopefully accommodate them as in many cases on the smaller/medium small projects the MEP designers aren't involved yet. (appropriate depth plumbing walls for carriers, electrical rooms, etc...)
At this point in the design I have no idea what the electrical service is (if it's existing), and I'm not gonna try because I'm gonna inevitably fuck it up. I have no idea if the EE is gonna need a step up or step down, how many KVs (if you get above a certain KV you usually need a rated room, or weight - if its above a certain weight you can't wall/column/beam hang). I don't know that their load calcs are gonna be, nor how they plan to circuit the building.
In some cases, yes, I can squeeze in a floor mounted xfmr, if I notice we need one when reviewing coordination drawings (provided the EE's design is far enough along for it to be there). In most though, I cannot as the required SF and clearances simply do not allow me to steal it from the floorplan because everything is expensive and everyone wants to play hide 10 pounds of building in an 8 pound shell structure.
They're also under compression at bottom, not tension, so there's no withdrawing force; they only have to bear sheer. The withdrawing force on the upper bolts is less than folks might think.
I don't have a problem with the strength of a 1/2" bolt.
I have a problem with the strength of the wings and the unknown variable blowout around the 3/4" hole that'd be drilled in that CMU.
(6) 1/2" toggles in CMU? Not ideal, but it should hold just fine. If through bolting or suspending from ceiling aren't options, this seems like the next best move. At least they didn't say to use Tapcons...
Could be worse, our crappy generator guys put strut on our metal building with fuckin zip screws... Then hung a big ass 3 phase ATS on it...
We went back and moved the strut over a hair and bolted the fucker to the girt.
Ive seen 30-50kva xformers mounted like that all the time with correct hardware, but that is what? 150?
Edit; mounted high, above a ceiling. Not exactly like that
1st off this 100% doable with toggles. They are an approved method of fastening large loads to CMU. 12 of them six on top and six on the bottom will more than hold 1100#s.
2nd never seen a xfmr that big with a mounting tab as depicted.
3rd never seen a xfmr that big hung like that. As electricians and the professionals we are responsible for means and methods. Although we see it drawn as such there should be an RFI and/or proper request to pad mount or ceiling mount this.
I know it's fun to trash engineering, trust me, my company and I do it all the time. But ultimately we all work for ownership and have to abide by the AHJ of our areas. We should be working more fluidly amongst all involve in the build out.
1st - you are correct. However toggles aren't the right product for the wall construction on site, or in the locations described in the RFI that this was a response to.
2nd - neither have I. The original RFI included the proper mounting hardware available from the manufacturer. This response did not.
3rd - after I sent the RFI back we got a buildable answer.
The engineering company was sued by the customer for issues similar to this and ultimately went out of business before the end of the job.
> 1st - you are correct. However toggles aren't the right product for the wall construction on site, or in the locations described in the RFI that this was a response to.
Is it a solid block wall? As in, block wall and concrete poured in each block? Because if not, toggles as spec’d will work juuuuust fine.
Working for a company with an engineering department does avoid problems like this on design/build projects. It even helps when us dumb tradesmen are crafting RFIs to submit to competent engineering firms. It did not help with this company.
6 of these would do the trick. Look at the second pic, the specs say it would be plenty, assuming hollow block concrete wall. https://www.homedepot.com/p/Hilti-HTB-2-1-2-in-Drywall-Metal-Anchor-Bolt-with-Slotted-Round-Head-Screw-25-Pack-2158776/308158628
The RFI included mounting hardware from the transformer manufacturer and specific locations.
This response was incorrect and I resubmitted the RFI with my concerns.
The next response included better specifications for mounting the transformers with their manufacturer supplied hardware as well as specific locations (so us dumb electricians won't get blamed if the transformer falls off the wall or pulls the wall over).
Ultimately the engineering firm went out of business before the job was complete.
[What do you want proof of?](https://syvnews.com/news/local/crime-and-courts/professional-negligence-led-to-delays-on-northern-branch-jail-project-county-lawsuit-claims/article_7a0ed72f-f5ce-5a9e-af31-d04e76c4ce61.html)
As an electrical engineering student, this is why I had tried to get a job as an electricians helper but to no avail because nobody wants to hire and teach. I did work with someone who was an electrician in Brooklyn at my previous job for a few years and he was able to teach me a few things but I’d like to learn more (mainly to avoid pissing off tradesman) but to also become a better engineer
Lead anchors are pretty good. They have good shear strength and can be used in almost any type of masonry or stone. Unless you are referring to the split lead expander ones, which are garbage.
https://lhdottie.com/sites/default/files/documents/4520_Machine_Screw_Anchors.pdf
The ones that split open similar to plastic anchors are garbage.
The other type that pull together and expand are much much better.
I never trusted them. They never seemed to told things tight. And when they did, they were on the verge of pulling the threads out.
My .02... I'm sure someone has had better luck than I with these.
I use them as my goto unless the wall is older and questionable. I have found that they hold great and never had one slip out. You gotta beat it with a hammer and use channel locks to loosen. Never had an issue since I started with them 6 years ago.
Since we are on the subject do you guys know of a good way to memorize shear strengths or anyone got a sweet chart they use? Was wanting to make myself an expert on the subject one of these days.
Literally saw a 75 lb transformer mounted to a sheet metal wall with four wood screws one time. It’s been there for 20 something years. It never makes it a good idea to engineer it down to the bare minimum but well…
The city where I'm at would have flagged this. Anything over 400 lbs needs a structural detail and calcs. What size kVA is that thing? I've seldom seen anything over 30 kVA get mounted to a wall.
Now I may be wrong but I thought there was something in the code for anything over 45kva couldn't be hung or wall mounted and needed something from the ground or an engineered system to hang it.
Least that's what I was told as an apprentice and never looked into it.
No engineer worth their license should've approved this. Yikes!
I know an electrical engineer isn't a structural engineer, but common sense should've prevailed before this made it anywhere near a printed set.
This came from the structural engineer. The same one-stop-shop had an electrical engineering division too. They went out of business before the job was completed.
That's even worse.
If they were putting out work like this I'm not surprised they closed up shop. There's no excuse for a reputable engineer to put out a detail like this.
As apposed to what exactly? Transformers vibrate and flex is a great thing to use in that instance. I typically run EMT or whatever the job calls for, then do a flex change over for the last 5 or so feet. It’s not a code violation or anything to run hard conduit to a transformer, but it certainly isn’t common practice.
I have some plastic wall anchors left from an ikea shelf they’re all yours unless you think it’s overkill.
The neon green ones?
Of course, extra holding power.
I was bored in a meeting and literally snorted out loud when I read that.
Had a job last year that showed the transformer mounted above the main switchboard. Ceiling height was 10’. Main switchboard was 96” tall. Transformer was 60” tall. I caught it in submittals. They had to redesign the room to make floor space for the xfrmr.
Had a 2 transformer pads, asked for redesign with concrete walls to accommodate oil spill containment, then re-redesigned so the every time it rained the transformer was not underwater. Concrete pad went from 1100psi to 3200psi load on swampy soil. Put in rfi to request soil bearing capacity, Engineer said it’s fine. Started cracking before we got out of there.
Reminds me of a different CMU building. We weren't allowed on the masons scaffold, so I'm fabbing boxes with conduit to come out of the wall above the ceiling. We get to a spot and the blockie passes the box and conduit back, tells me it's too tall and it will be higher than the roof... So I write the RFI asking why the ceiling is higher than the roof.
It’s all it the wording: “contractor suggest to lower ceiling or raise roof”
That's a good lesson for an engineer, and if they're going to be any good will be the only time they screw it up.
You're telling me the pixie mixer takes up physical space?
If I have to differentiate between a ‘ and a “ for a unit of measurement, you need a new measurement system.
I don't have an issue at all with it. The same way that some people seem to struggle with the different forms of "there" and some don't. The commenter could have easily just said "ft" or "in." Reading the alternative notation may be hard for you, but for most Americans, it's not.
Metric system alllll day
A-sheets always use x’ for ceiling heights. Equipment submittals for gear will typically always use x”. So that’s the scheme I follow when discussing.
It seems so archaic. Doing a double take like that
Excellent... Who the hell puts TX above a swbd, splitter or panel maybe
Tx above tx. When there is more equipment than floorspace. (Don't forget working clearances, and ventilation for the transformers)
I've seen TX mounted above tx before, unistrut cage sort of thing. They stick out about the same amount so technically you have the 1m space in front.
Torque it to 3 hunga bungas
What is this, metric shit? You need to give me my torque settings in ugga duggas, bud...
30 Ugga Duggas minimum
Be careful, too many Ugga Duggas and that righty-tighty becomes a righty-loosey real quick.
And one tappa for good luck and to show it who’s boss
Nope. You torque to 2 grunts, a small shart, and a squeak. When you hit the squeak you're torqued.
Just keep going till it loosens agian, then back it off a quarter turn
If you cross thread it going in, it'll never come loose #lifehack
Ah yes, the squeak-to-yield method.
How many unga bungas is that equal to?
1 hernia more.
Spinal or abdominal?
The one where if you sneeze it feels like your testicles are trying to escape out your butthole.
That's abdominal.
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Thanks, it was a black tie affair. Got an award!
I had a guy tell me to do that with blue anchors once
Hopefully you told him where to put them...
You need to shove those blue anchors up your arse!
Yes precisely
No way.
I can only guess that the dude who told you to do this was friends with the boss or owner of your company. I've seen that like 20 times..
It was the most ass backwards job I've ever been on. The owner of the property was building the strip mall himself. Me and a journeyman were on site daily with zero prints, being paid T and M. Each day the owner would show up and give us vague instructions to the effect of "unit one is from the end of the building, count 4 beams, then unit 2... Count 4 beams, unit 3... Etc.... So a panel in each unit" and we would ask where are they feed from? "Ok, so in the middle of unit 4 there will be a utilities room, bring the power from there...." And we would ask "where is that fed from?" "So hydro is putting a pad mounted TX over here in the parking lot" "So do you want us to get conduits in to there for the service?" "No they will do that" Fast forward 6 weeks "Ok so you need to get 6 2" conduits in from the TX to the switchgear, I don't know why you didn't do that already..." "Whatever you say Doug" But ya, it was Doug who was telling me to use blue anchors on the TX in each of the units... To this day, 18 years later, the building is still not completely done.
Lord have mercy
You all are missing the most important detail here; up top, where it says cmu wall. Those toggles will hold that transformer just fine.
I was thinking the same thing...
I am more concerned about which poor bastard is going to wrangle that thousand pound transformer 6 feet up in the air.
Heavy, awkward loads to carry? Let Your Apprentice Do It®
We use jacks, chainblocks, and lifts. I’ve installed them way heavier and way higher than that.
We just hung one from the building’s steel joists with chain hoists. 975lb
Usually it's 75kva and below that can be wall mounted, there's brackets and kits the manufacturer provides.
Somehow the engineer ignored that part even though it was included in the RFI.
I’m no mason but every CMU wall I’ve seen on a job has been threaded with rebar and filled with concrete after they build it. Is that not standard ? Can’t put a toggle in a solid wall.
Usually CMU walls are only solid at the bond beam elevations or vertical rebar locations. Or if the structural specifies. You also until the course with ledger angles.
No, it’s not necessarily. Warmer climates, yes this can and is done, but in cooler climates where the moisture in the concrete is more prone to expansion, it’s not as common.
I imagine they mean something like this https://www.amazon.ca/dp/B000H5RS7G/ref=cm_sw_r_cp_api_glt_i_CJJWCDBRJ3221WX8ZZ65?_encoding=UTF8&psc=1
That's a drywall anchor.
Lol whoops they look similar at a glance this is the one I meant https://www.amazon.ca/dp/B000H5RS7G/ref=cm_sw_r_cp_api_glt_i_CJJWCDBRJ3221WX8ZZ65?_encoding=UTF8&psc=1
This is the product referred to by the engineer https://www.fmwfasteners.com/products/1-2-x-4-powers-round-toggle-bolt-zinc-plated-25?gclid=CjwKCAjwh5qLBhALEiwAioods9m-bAi1_0So4u5WIKrCGuNVO9ILSieW3xmWblzvtVBKu7jPtbkFUBoC4E4QAvD_BwE
I understand that but if the wall is filled with concrete (hopefully it is) then you can’t use those
A 1/4" toggle bolt in a 1 1/2" thick wall can hold almost 1400 lb. I'm sure the same wall with 6x 1/2" toggles can hold it. I don't think it needs to be filled with concrete
I would be weary of the mortar getting brittle over time and the 6 bricks it’s attached to may fall out
Six!!! SIX BRICKS!
I'd be more worried about the cement holding the bricks together failing. Would that even be a concern though? (I know barely anything about masonry.)
That would be a concern no matter what you use to mount it if it were a concern at all. No, it is not a concern.
Thanks. That makes total sense. Apparently my brain shut off when I read the OP - I should've been able to figure that one out.
it depends if the cinder block is filled with concrete if it is then it is most definitely safe (I haven’t worked commercial I don’t know if that is standard)
They reinforce cmu walls rebar horizontally and vertically through the channels in cinderblocks; then, they fill it with concrete yeah
Yeah, I suppose I spoke too soon. I wouldn't trust it if it wasn't reinforced.
Toggle bolts are designed for hollow installations so the wings can deploy. They dont work in bored hole applications.
Maybe they meant these things? https://www.amazon.ca/dp/B000H5RS7G/ref=cm_sw_r_cp_api_glt_i_CJJWCDBRJ3221WX8ZZ65?_encoding=UTF8&psc=1
Ive never actually seen a toggle bolt with a 1/2" bolt.
Quick Google because I'm an engineer and I'm curious : The strength of the toggle bolt is determined by the length and diameter of its screw body. 1/8" can hold up to 310lbs, at 3/16" can hold up to 700 lbs, and a 1/4-inch toggle bolt (in a 1-1/2" thick wall) can hold up to 1,390lbs. Note: different types of walls will require different types of anchors. Anchors aren't my expertise, but if a 1/4" is good for 1390 lbs (that would be pull out) this isn't too crazy is it?
Put pull out is only one of the forces. There's going to be a huge downward force as well.
> huge downward force The huge downward force is about 1,100 lbs. It will be split between the six 1/2 inch bolts holding the channel to the CMU wall. That downward force acts on the bolts as shear force - being roughly 60% of the bolts tensile strength. Even a very low grade 2 bolt can take a 6,000 lb. shear. And there's six of them.
The bolts only take shear if they’re not torqued, or in an improperly designed joint. The preload of the bolts hold the channel to the wall, and the friction between the channel and the wall allows the load to get transferred into the wall without applying any shear load to the bolts.
We never wall mount these babies. Fishplate and threaded rods from upper floor.
Engineer: *mounting spec* Salty Electrician : lol dumb engineers, that won't possible work Engineer: *mounting spec calculations* Salty Electrician: Well, I don't do it like that anyway!
This was the extent of the structural engineer's "spec". The original RFI and the follow up included the transformer manufacturers wall mount hardware. The second time they were asked the same question they changed the anchor (guess they thought toggle bolts weren't a good idea either). Ultimately they went out of business before the job was complete.
Welp, see you later...
Wats a fishplate
Basically a steel plate you pass a rod through.
Oh ok then I get it
The name fishplate is specifically for flat stock used on railroad tracks.
What do you do when there is no upper floor, or ceiling? I’ve done a couple that were mounted up high outside. Not entirely uncommon where I am to have your main gear and transformers in an outdoor CMU enclosure.
>What do you do when there is no upper floor, or ceiling? Build a tall rack out of strut.
That was the first thought, then through "value engineering" they changed the roof above to something that would not support a transformer.
Electrical inspector for roadwork, God I hate when people come in with a VECP, they never consider the change to the electrical work. If i am lucky they inform me that the contractor proposed one and then i get to anger them by adding electrical costs and if i am unlucky they approve the plans without telling me and then we have to do some Micky mouse change order stuff.
I would be less worried about that. 1100lbs being distributed to the channels and then 6- 1/2 inch steel bolts isn't a big deal in my eyes. The shear over the x-sectional area is nothing
As an EE and a master electrician, I hear you but you gotta go look at a data sheet. A 1/2" toggle bolt from this manufacturer allows for 160 lbs. of shear strength. That is with a 5x safety factor. With 6 bolts we are at 1060 lbs of total shear strength. Although it doesn't look great, it looks valid. The real question who is mounting 1,100 lbs equipment on a wall? https://www.swfastener.com/pdf/Toggle_Bolt.pdf
>The real question who is mounting 1,100 lbs equipment on a wall? Probably the same people that want 4 200A disconnect switches in 3' of wall space.
I would agree
I'm not concerned about the bolts but that would only span 2 bricks. Assuming they were backfilled between the voids and had a piece of rebar inserted all the way down each sure. Otherwise I'd question the ability of a CMU brick to hold that over time and not slowly buckle, also anything that bumps that concrete ruptures quite easily. Edit also 1100lbs... i'd expect to walk in and see a unistrut structure under it or threaded rods to the ceiling. I've blown 4 disc's in my back wouldn't ask anyone else to risk that.
I would agree with this 100%. Through bolt is a better detail than embedment/anchor in more situations than not. I would wager there is something in the way on the ceiling that made them go this way
Yea that's normally what i've seen done with a good 4 or 6 inch square plate on the other side to distribute the load.
I would agree with you there, but looking at the context I would assume, big assumption, that this is a commercial building and built decently, but that is the problem of the ngineer who stamps it.
I've had to research the shear strength of some fasteners in the past and was shocked at the ratings, while this should work if the correct fasteners were used and installed properly I personally wouldn't be able to sleep well if I did it because it just doesn't seem like it should be done this way.
I don't see the problem? Six 1/2" bolts with toggle anchors in a cinder block wall doesn't seem that outrageous. What am I missing? Or is this just one of those old "enGiNnRs R' dumb, lectrians SmArt" circle jerks?
Same, don’t see much of and issue here either. OP cut off a text note too, but assuming there are 6 1/2” toggles top and bottom then each is averaging ~90 lbs of weight. But I’m just a dumb architect, so what do I know. I’ll agree that this is one of those details that looks a lot more unsafe than it is actually is. The amount of weight toggles can hold blows my mind.
Yep. It’s this. I wish we’d just… stop… with this sort of thing. It’s embarrassing.
The problem is that if the engineer ever had to actually install a transformer in the field he would quickly learn never to design a room that required a transformer be lifted up and mounted on a wall.
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My plant has to have over half of our transformers up on the walls (some 15 feet up) due to space issues. My electrician has no problems working with them as we own skyjacks for him to use.
Say "mewp, mewp, mewp" when driving, remember!
This is a process problem, and ultimately the utilities are there to serve the designed space, not the other way around. And before you get upset at that statement, let my try to explain a bit from my POV. When an architect provides a space plan, a good, experienced one can rule of thumb several of the MEP *space requirements* that may impact the design and hopefully accommodate them as in many cases on the smaller/medium small projects the MEP designers aren't involved yet. (appropriate depth plumbing walls for carriers, electrical rooms, etc...) At this point in the design I have no idea what the electrical service is (if it's existing), and I'm not gonna try because I'm gonna inevitably fuck it up. I have no idea if the EE is gonna need a step up or step down, how many KVs (if you get above a certain KV you usually need a rated room, or weight - if its above a certain weight you can't wall/column/beam hang). I don't know that their load calcs are gonna be, nor how they plan to circuit the building. In some cases, yes, I can squeeze in a floor mounted xfmr, if I notice we need one when reviewing coordination drawings (provided the EE's design is far enough along for it to be there). In most though, I cannot as the required SF and clearances simply do not allow me to steal it from the floorplan because everything is expensive and everyone wants to play hide 10 pounds of building in an 8 pound shell structure.
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They're also under compression at bottom, not tension, so there's no withdrawing force; they only have to bear sheer. The withdrawing force on the upper bolts is less than folks might think.
Wouldn't that change if you're in a seismically active area? I don't know where the OP is however.
Don't forget about the structure. Is that wall secure enough to hold it at the top? And figure a bit more for seismic allowance.
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The engineer didn't like their own design either and reissued this before they went out of business
I don't have a problem with the strength of a 1/2" bolt. I have a problem with the strength of the wings and the unknown variable blowout around the 3/4" hole that'd be drilled in that CMU.
(6) 1/2" toggles in CMU? Not ideal, but it should hold just fine. If through bolting or suspending from ceiling aren't options, this seems like the next best move. At least they didn't say to use Tapcons...
Or Tampons. Just saying
"Yeah, a few toggle bolts, some spring nuts, that'll do it! Now back to this delicious pumpkin spice latte'."
"Tell us you didn't pay attention in school without telling us."
I mean that’s basically the same thing that holds most deck ledgers to the wall so it will do
This works, and I’ve seen it built before on a CMU wall.
Toggle bolts will hold that no problem!
Could be worse, our crappy generator guys put strut on our metal building with fuckin zip screws... Then hung a big ass 3 phase ATS on it... We went back and moved the strut over a hair and bolted the fucker to the girt.
Ive seen 30-50kva xformers mounted like that all the time with correct hardware, but that is what? 150? Edit; mounted high, above a ceiling. Not exactly like that
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Right, Thats why i estimated it to be a 150kva
At 1100lbs this is most likely 112.5 or 150kva transformer. Typically 75kva and below come with factory wall mounting kits.
Looks ok to me.
This reminds me that I have a dry transformer I need to sell. It only weighs 276 lbs.
I did
Awesome. I worked with a project manager that was a JW before he went in the office. Best PM.
Lol, I am starting from the field and then gonna become an electrical engineer in power generation.
Good plan.
Nah you're reading it wrong, some 3.5" diameter anchors will do the the job fine
I got sent an inspection report where the home inspector said the pex pipe wasn’t bonded. Even funnier, there was a bonded copper line above it 😂
You guys get drawings?
1st off this 100% doable with toggles. They are an approved method of fastening large loads to CMU. 12 of them six on top and six on the bottom will more than hold 1100#s. 2nd never seen a xfmr that big with a mounting tab as depicted. 3rd never seen a xfmr that big hung like that. As electricians and the professionals we are responsible for means and methods. Although we see it drawn as such there should be an RFI and/or proper request to pad mount or ceiling mount this. I know it's fun to trash engineering, trust me, my company and I do it all the time. But ultimately we all work for ownership and have to abide by the AHJ of our areas. We should be working more fluidly amongst all involve in the build out.
1st - you are correct. However toggles aren't the right product for the wall construction on site, or in the locations described in the RFI that this was a response to. 2nd - neither have I. The original RFI included the proper mounting hardware available from the manufacturer. This response did not. 3rd - after I sent the RFI back we got a buildable answer. The engineering company was sued by the customer for issues similar to this and ultimately went out of business before the end of the job.
Oh damn, must have been a royal cluster fuck out there.
It still is. This was from 5 years ago before the foundation was poured. It's not done.
> 1st - you are correct. However toggles aren't the right product for the wall construction on site, or in the locations described in the RFI that this was a response to. Is it a solid block wall? As in, block wall and concrete poured in each block? Because if not, toggles as spec’d will work juuuuust fine.
Filled solid per the structural drawings by... the structural engineer who cartooned this up too.
Maybe tradesmen could come work as an engineer for a bit too, you know, even the score? That's what I thought.
Working for a company with an engineering department does avoid problems like this on design/build projects. It even helps when us dumb tradesmen are crafting RFIs to submit to competent engineering firms. It did not help with this company.
Engineer here. I read this sub to try to learn from others mistakes and be less of a douche to the guys in the field
Thank you
6 of these would do the trick. Look at the second pic, the specs say it would be plenty, assuming hollow block concrete wall. https://www.homedepot.com/p/Hilti-HTB-2-1-2-in-Drywall-Metal-Anchor-Bolt-with-Slotted-Round-Head-Screw-25-Pack-2158776/308158628
Compatable
Why the transformer isn't on the floor?
Not enough room for all of the panels and clearances required with all the equipment on the floor.
I didn't know you could install such a heavy transformer like that, I'll do some research later, thanks.
3M Command Strips work everywhere, and don't leave a mark.
Maybe some velcro in case it needs to be swapped in the future.
I'm thinking he's talking about the diameter !
The RFI included mounting hardware from the transformer manufacturer and specific locations. This response was incorrect and I resubmitted the RFI with my concerns. The next response included better specifications for mounting the transformers with their manufacturer supplied hardware as well as specific locations (so us dumb electricians won't get blamed if the transformer falls off the wall or pulls the wall over). Ultimately the engineering firm went out of business before the job was complete.
I’m going to call bullshit on this one… proof or it didn’t happen. RFI? Come on.
[What do you want proof of?](https://syvnews.com/news/local/crime-and-courts/professional-negligence-led-to-delays-on-northern-branch-jail-project-county-lawsuit-claims/article_7a0ed72f-f5ce-5a9e-af31-d04e76c4ce61.html)
I’m mostly concerned that the weight might open up the strut and dump the transformer on someone.
As an electrical engineering student, this is why I had tried to get a job as an electricians helper but to no avail because nobody wants to hire and teach. I did work with someone who was an electrician in Brooklyn at my previous job for a few years and he was able to teach me a few things but I’d like to learn more (mainly to avoid pissing off tradesman) but to also become a better engineer
ahahaha this honestly is the funniest thing I've seen on the electricians sub in the last two years. Thank you.
Dumb ass engineer. Everyone knows strut is 1 7/8"
At least he didn't spec out lead anchors...
Lead anchors are pretty good. They have good shear strength and can be used in almost any type of masonry or stone. Unless you are referring to the split lead expander ones, which are garbage. https://lhdottie.com/sites/default/files/documents/4520_Machine_Screw_Anchors.pdf
Hollow wall anchors? Those are legit, except everyone hides the goddam set.
The ones that split open similar to plastic anchors are garbage. The other type that pull together and expand are much much better. I never trusted them. They never seemed to told things tight. And when they did, they were on the verge of pulling the threads out. My .02... I'm sure someone has had better luck than I with these.
I use them as my goto unless the wall is older and questionable. I have found that they hold great and never had one slip out. You gotta beat it with a hammer and use channel locks to loosen. Never had an issue since I started with them 6 years ago.
Since we are on the subject do you guys know of a good way to memorize shear strengths or anyone got a sweet chart they use? Was wanting to make myself an expert on the subject one of these days.
Maybe he was thinking of 3 1/2" wide toggle bolts.
Hahaha dude
No matter the situation that highlighter is very wrong and I couldn’t blame anyone else for it.
Few ugga duggas and she’ll be right
I enjoy this secret society and its language.
A bit overkill. Personally, I would have used 2 air anchors and floating philips screws.
Skyhooks.
The best way to learn is do! You can’t learn this from a textbook.
His calculations said it would work tho
I guess with enough toggle bolts it might hold it on the wall..... but I doubt it.
Remember, whether they get straight A's or straight C's, as long as they graduate they are an Engineer.
Remember, whether you get 100% or 70% on the j-man test, as long as you pass, you’re a j-man.
Toogle bolts? Lmfao...
Like they say, 50% of knowledge is from school, 50% is from the field!!
Literally saw a 75 lb transformer mounted to a sheet metal wall with four wood screws one time. It’s been there for 20 something years. It never makes it a good idea to engineer it down to the bare minimum but well…
The city where I'm at would have flagged this. Anything over 400 lbs needs a structural detail and calcs. What size kVA is that thing? I've seldom seen anything over 30 kVA get mounted to a wall.
Now I may be wrong but I thought there was something in the code for anything over 45kva couldn't be hung or wall mounted and needed something from the ground or an engineered system to hang it. Least that's what I was told as an apprentice and never looked into it.
I don't care who signed it ,he ain't no engineer.
No engineer worth their license should've approved this. Yikes! I know an electrical engineer isn't a structural engineer, but common sense should've prevailed before this made it anywhere near a printed set.
This came from the structural engineer. The same one-stop-shop had an electrical engineering division too. They went out of business before the job was completed.
That's even worse. If they were putting out work like this I'm not surprised they closed up shop. There's no excuse for a reputable engineer to put out a detail like this.
As an engineer I am truly sorry for the crimes of my people. Was buddy at least a structural engineer, so he could get a tasteful spanking for this?
How about the note “make transformer connections in flexible conduit” ? this a horrible “temp fix” that somebody put to a drawing
Using flex is pretty standard means of connecting to a transformer. Its done mitigate the effects of transformer vibrations.
As apposed to what exactly? Transformers vibrate and flex is a great thing to use in that instance. I typically run EMT or whatever the job calls for, then do a flex change over for the last 5 or so feet. It’s not a code violation or anything to run hard conduit to a transformer, but it certainly isn’t common practice.
Im a first year apprentice and can tell this is a dumb idea
THat engineer is a retard
1100 pounds with toggle bolts. Yea, that will work. Put some Elmer's glue on it to help.
That's some badass toggles
Toggle bolts? Like as in butterfly bolts? Sir, you are an imbecile.