EMT into Plastic Boxes

[BentBierz]

Hello,

Stopped by an acquaintance's house this weekend to look at his steel building project. He is about 2-3 months ahead of me so was interested in seeing some of the things he has done. One of the things that stuck out was his running either EMT or FMC into plastic boxes or, in several cases, running EMT in between boxes. He, like me, does not plan to use any Romex primarily due to ocassional rodent problems from living out in the country and, in my case, having a bayou that cuts across the back corner of my property. I asked why he was using plastic boxes (he is using the heavier plastic boxes and drilling a hole in the box to accept the metal connectors) and he said he had scored two book boxes full of them at an estate sale for next to nothing.

I told him that I was not sure if you could connect plastic to metal like he was doing but, as we both discussed, he is running a ground wire everywhere he pulls wire so is it really an issue? At any rate, here are some pictures I took at his place this weekend. Thoughts? Code?

 

[sberry]

The conduit isn't grounded.

 

[BentBierz]

The conduit isn't grounded.

But that is the point of the question...if he is running a ground wire with all of his runs why would the conduit need to be grounded? If it is code that any metal part must be grounded than I guess that answers the question. Thanks.

 

[rlitman]

...If it is code that any metal part must be grounded than I guess that answers the question...

It is. At least one end of the conduit needs to go into a metal box that is grounded. That ground can come from a ground wire within the conduit.

 

[BentBierz]

It is. At least one end of the conduit needs to go into a metal box that is grounded. That ground can come from a ground wire within the conduit.

Thanks. If I understand your answer correctly, the picture that has FMC to a plastic box is fine because it is EMT/FMC/metal j-boxes from the circuit panel all the way to the first plastic box but the picture that has EMT connecting two boxes is against code because it breaks the continuous ground between raceways.

 

[Angelfire]

I believe the act of drilling out holes in the boxes removes it's listing which would be another code infraction.

 

[slackdaddy1]

My understanding any modification (or use not specified by manufacture) nullifies the UL rating.

 

[Furd50]

I agree with Angelfire and slackdaddy1. I also think that as violations go, these are pretty minimal and IF I was not going to have the work inspected i might do the same things.

 

[ddawg16]

All the code violations aside.....

Why would anyone want to use plastic boxes in a garage?

In my experience, outlets take a beating in the garage...it's not like we are plugging in a mixer....

Just a personal opinion...but, this is a good example of how a pole barn/steel building is not really cheaper than stick built. You have to go through so much more stuff to finish it out, the up front savings is quickly lost.

 

[PoorOwner]

But that is the point of the question...if he is running a ground wire with all of his runs why would the conduit need to be grounded? If it is code that any metal part must be grounded than I guess that answers the question. Thanks.

Just imagine someone comes along and shoot a nail with a nail gun, it somehow damage the EMT and pinched the hot on the tubing wall, but nothing else. Since your friend didn't ground these EMT, the whole section of EMT is now energized in the wall.. very low probability.. but just to demostrate the point.

Just get metal boxes for your new construction.

 

[amolaver]

All the code violations aside.....

<snip>

Just a personal opinion...but, this is a good example of how a pole barn/steel building is not really cheaper than stick built. You have to go through so much more stuff to finish it out, the up front savings is quickly lost.

Genuinely curious what you mean by this - what makes this more expensive than stick? Emt/thhn vs nm?

I live in termite country (mid Atlantic) and I did not want to deal with those issues. I couldn't be happier with my metal building - once the slab was down, it was built by three guys (pros, not me ) in a week, insulation and all. Running electrical has been relatively easy since it's all exposed (emt & boxes mounted to unistrut). I think of drilling endless holes in studs and get the heebie jeebies

ahm

 

[BentBierz]

All the code violations aside.....

Why would anyone want to use plastic boxes in a garage?

\

Well, as I prefaced the discussion...two book boxes full (probably $150-$200 Home Depot value) of very cheap, estate sale hard shell PVC boxes (http://www.homedepot.com/p/2-Gang-34-cu-in-Heavy-Wall-Old-Work-Box-BH234R/100177871) at his disposal.

Putting aside the grounding/bonding issue of plastic boxes for a moment (and some very good points have been made stating the code issues), I would have no issue with the heavy-duty plastic boxes for a lot of garage applications...not all but many.

I don't know the guy other than my family realtor knows him and hooked us up so that we could check out each others steel building projects. He, like me, wants to do the right, safe thing within our respective budgets. I don't happen to have a bunch of almost free plastic boxes so will go steel but wanted to bring the topic up for discussion.

 

[BentBierz]

Just a personal opinion...but, this is a good example of how a pole barn/steel building is not really cheaper than stick built. You have to go through so much more stuff to finish it out, the up front savings is quickly lost.

I'm still on the fence about this but I can definitely say that my steel building has easily gone 1 1/2-2 times over my personal budget.

 

[BentBierz]

Just imagine someone comes along and shoot a nail with a nail gun, it somehow damage the EMT and pinched the hot on the tubing wall, but nothing else. Since your friend didn't ground these EMT, the whole section of EMT is now energized in the wall.. very low probability.. but just to demostrate the point.

Just get metal boxes for your new construction.

Very solid point...thanks!!!

 

[barnjunkie]

When I finish a job, I would rather someone tell me that the job looks great rather than "..you've gotta see this $h!t."

 

[zmaxmotorsports]

I believe the act of drilling out holes in the boxes removes it's listing which would be another code infraction.

 

[BentBierz]

When I finish a job, I would rather someone tell me that the job looks great rather than "..you've gotta see this $h!t."

OK...I've probably spent more time than I should trying to line up the wit of your comment to the reality of the discussion and have kind of come up empty. I've seen some hacked-a$$ed stuff in my life that met code --and-- MILSPEC (where I have spent a lot of my life). "Looks great" has little to do with code and "you've gotta see this $hit" could very well meet code to the fullest.

 

[wyliesdiesels]

The points i wouldve made have already been stated so Im just agreeing with those previous comments.

Drilling out the boxes violates the listing.

And any metal object needs to be grounded to prevent it from becoming energized. So that marooned piece of EMT is not good. He should use a bonding bushing to bond that section of conduit...

 

[rharman]

Bonding Bushing.... I learned something today. Gotta love this place.

Thanks Wylies.

 

[ford33]

Saving $200 on a long-life installation of suspect quality seems foolish. Running ground wires in conduit and then connecting all the devices with ground wires is surely taking more time and costing more money in wire and time. If you use metal boxes the devices are grounded to the box when you connect them. No ground wire needed. Correcting this in the future would be move expensive than the savings.

Sell the box of boxes and use the money to buy the correct devices.

Do it right the first time!

 

[wyliesdiesels]

Bonding Bushing.... I learned something today. Gotta love this place.

Thanks Wylies.

You're welcome.

Heres a pic for your reference:

 

[BentBierz]

The points i wouldve made have already been stated so Im just agreeing with those previous comments.

Drilling out the boxes violates the listing.

And any metal object needs to be grounded to prevent it from becoming energized. So that marooned piece of EMT is not good. He should use a bonding bushing to bond that section of conduit...

To the point and with clarity!

BTW...your use of the word "marooned" really brings into focus the real issue at hand...thanks!

 

[BentBierz]

Saving $200 on a long-life installation of suspect quality seems foolish. Running ground wires in conduit and then connecting all the devices with ground wires is surely taking more time and costing more money in wire and time. If you use metal boxes the devices are grounded to the box when you connect them. No ground wire needed. Correcting this in the future would be move expensive than the savings.

Sell the box of boxes and use the money to buy the correct devices.

Do it right the first time!

Coming from a Coast Guard "culture of safety" I find no fault in your "sell the box of boxes" argument! For my own building, especially after this discussion, it will be all metal fixtures but I will still run a ground wire...probably a waste of money but it is mine to waste.

I appreciate everyone's input...it kept me from going down a road that seemed to "make sense" but, once discussed, showed not only the code issues but the safety issues. I have spent many years as a commercial vessel inspector enforcing the Code of Federal Regulations (CFRs) and I can say that, in general and especially our electrical regs, "code IS safety."

 

[AffableCurmudgeon]

Just because something is cheap, does not make it the right thing to use...
Electrified conduits would keep me awake at night.

 

[Zippercat]

I believe the act of drilling out holes in the boxes removes it's listing which would be another code infraction.

Pardon me for going a tad off topic: Several times I've added a screw, like a drywall screw or whatever is handy, through the side of a wobbly plastic box to more firmly secure it to a wood stud. Would that also be against code? Thanks!

 

[yeldogt]

Why do people do this? Spend valuable time on a project with obvious 2nd tier results.

I have friends that do this -- they feel compelled to save as much as possible vs What I feel is more logical ........ doing a good/proper job for less.

What am I missing?

 

[BentBierz]

Why do people do this? Spend valuable time on a project with obvious 2nd tier results.

I have friends that do this -- they feel compelled to save as much as possible vs What I feel is more logical ........ doing a good/proper job for less.

What am I missing?

I doubt that you are missing much...chalk it up to human nature, redneck engineering, not enough time to do the job right but plenty of time to do it over, etc.

 

[teamextreme]

I agree with everyone's analysis, but would also add that the dollars saved with his bargain box of boxes is nowhere near the $150 to $200 listed, unless this is one gigantor box. 1 gang nail-ons are well under a buck. My 1000 sq ft build that has all kinds of electrical run through it is lucky to have $50 in boxes. Another example of spending a dollar to save a dime. Wylies example of bonding bushings for example, while a brilliant solution, cost more than the plastic box and create a bunch more work.

 

[BentBierz]

I agree with everyone's analysis, but would also add that the dollars saved with his bargain box of boxes is nowhere near the $150 to $200 listed, unless this is one gigantor box. 1 gang nail-ons are well under a buck. My 1000 sq ft build that has all kinds of electrical run through it is lucky to have $50 in boxes. Another example of spending a dollar to save a dime. Wylies example of bonding bushings for example, while a brilliant solution, cost more than the plastic box and create a bunch more work.

I was basing the approx. dollar amount off of Home Depot pricing for the following: http://www.homedepot.com/p/2-Gang-35-cu-in-Electrical-Hard-Shell-Box-BH235AR/202077370 this is what he seemed to be using the most of. Not certain how many two book boxes would hold but it would be a few.

 

[BentBierz]

I had spray foam insulation put in my building and ran out of funds to also spray the thermal barrier on anything other than the ceiling and a few feet down each wall from the ceiling. All my walls will need at least 1/2" drywall to meet fire code where I didn't spray the thermal barrier and I want to put 1/2" plywood on top of that in the shop area. Because of that thickness I will be using this type of box in some areas http://www.homedepot.com/p/2-Gang-3...ox-MB238ADJ-3R/202924554?keyword=034481193449 unless I come up with a different plan.

 

[rburke65]

He bought plastic "old work" boxes to use in his metal building? Oh.......

 

[BentBierz]

He bought plastic "old work" boxes to use in his metal building? Oh.......

No...they are new work boxes.

 

[wyliesdiesels]

He bought plastic "old work" boxes to use in his metal building? Oh.......

Negative.

Theyre nail-ons which are "new work" boxes.

Old work boxes can only be used with a wall already finished with drywall or another material.

 

[rburke65]

In post number #12 the Home Depot link, those are old work boxes.

 

[BentBierz]

In post number #12 the Home Depot link, those are old work boxes.

Sorry...my bad, you are correct! The proper link was in post #29.

 

[barnjunkie]

Saving $200 on a long-life installation of suspect quality seems foolish. Running ground wires in conduit and then connecting all the devices with ground wires is surely taking more time and costing more money in wire and time. If you use metal boxes the devices are grounded to the box when you connect them. No ground wire needed. Correcting this in the future would be move expensive than the savings.

Sell the box of boxes and use the money to buy the correct devices.

Do it right the first time!

six-pack!!

 

[6768rogues]

Since he has plastic boxes to save money, how about using plastic conduit, too? The issue of drilling holes in boxes still exists, but the grounding of conduit is gone and a person looking to save money on boxes also saves money on conduit.

 

[penright]

Pardon me for going a tad off topic: Several times I've added a screw, like a drywall screw or whatever is handy, through the side of a wobbly plastic box to more firmly secure it to a wood stud. Would that also be against code? Thanks!

I might have missed it... Is what @Zippercat asking true? Does drilling a new mounting hole lose the UL listing?

 

[dscheidt]

I might have missed it... Is what @Zippercat asking true? Does drilling a new mounting hole lose the UL listing?

Unless it's listed for field modification, modifying it makes it unlisted.

 

[sberry]

If I do something like that I make sure it doesn't miss the intent. There is a good reason for most of the rules. If I stick a section of ground bar in an old panel cause the first guy wired it wrong I don't worry so much if it is listed, I make sure it has a threaded hole screwed in to and that it isn't going to come loose, better than having it wired wrong.
A while back I ran across a place the old fart had used an abandoned water pipe as a neutral, only 2 service conductors to the garage and what a fuggin mess. No money, no brain, shocks all over. There was a switch loop for a light in it, I used it to make a 3rd wire. Didn't charge, didn't sign anything, will never admit to being there, at least stopped them from electrocuting a kid at the moment.