New Job Has Caused Some Confusion

[K_Buz]

I'm new here, but I've been in the trade (mostly resi and commercial) for 15 years. For the majority of those, I've worked for a guy who was a code genius and adhered to every code and some I swear were just in his head, so I consider myself to be pretty knowledgeable.

A couple months ago I changed employers. Along with trying to learn how things are done and what is expected, I am also finding myself questioning some things what I thought were code.

1) Is there anything in the code that says you have to use an extension box for the KO's and that you can not use the extra space for box fill?

2) We were wiring an outdoor, free standing sub panel and I asked who had brought the ground rods. The response was that ground rods were not needed because the sub panel was not servicing a building/structure. I always thought that a sub panel supplied by an underground was considered a new service and therefore needed ground rods. Am I mistaken?

 

[jumper]

Q1.??? Restate please

Q2. A free standing sub panel is not a separate service, but is on a separate structure and a GES is required.

250.32 Buildings or Structures Supplied by a Feeder(s)
or Branch Circuit(s).

(A) Grounding Electrode. Building(s) or structure(s) supplied
by feeder(s) or branch circuit(s) shall have a grounding
electrode or grounding electrode system installed in
accordance with Part III of Article 250. The grounding
electrode conductor(s) shall be connected in accordance
with 250.32(B) or (C). Where there is no existing grounding
electrode, the grounding electrode(s) required in 250.50
shall be installed.

Exception: A grounding electrode shall not be required
where only a single branch circuit, including a multiwire
branch circuit, supplies the building or structure and the
branch circuit includes an equipment grounding conductor
for grounding the normally non?current-carrying metal
parts of equipment.

 

[resistance]

I'm new here, but I've been in the trade (mostly resi and commercial) for 15 years. For the majority of those, I've worked for a guy who was a code genius and adhered to every code and some I swear were just in his head, so I consider myself to be pretty knowledgeable.

A couple months ago I changed employers. Along with trying to learn how things are done and what is expected, I am also finding myself questioning some things what I thought were code.

1) Is there anything in the code that says you have to use an extension box for the KO's and that you can not use the extra space for box fill?

2) We were wiring an outdoor, free standing sub panel and I asked who had brought the ground rods. The response was that ground rods were not needed because the sub panel was not servicing a building/structure. I always thought that a sub panel supplied by an underground was considered a new service and therefore needed ground rods. Am I mistaken?

#1 No.
#2 Free standing?seems it would need one. Please explain the install further.

 

[jumper]

Just figured out Q1. No, as already stated by resistance above.

 

[augie47]

While I agree with Jumper's answer on Q2 due to the Code definition of a "structure", I believe you will find the requirement for a grouning electrode on a free standing sub-panel may vary greatly by jurisdction.
I seldom see a small subpanel on a post etc. feeding one or two recpetacles.

 

[Twoskinsoneman]

#1 Extension rings add to the total fill volume.

314.16(A) Box Volume Calculations. The volume of a wiring
enclosure (box) shall be the total volume of the assembled
sections and, where used, the space provided by plaster
rings, domed covers, extension rings, and so forth, that are
marked with their volume or are made from boxes the dimensions
of which are listed in Table 314.16(A).

#2 agree with resistance when you consider the definition of structure a free standing sub still needs and the electrode

100(I) Structure. That which is built or constructed.

 

[K_Buz]

I piped in some switches in a commercial building and put a 4x4x2 1/8 box at the top of the wall for a pull point. The guy who was running the job was concerned that the box wouldn't be large enough. I told him that if anything we would just install an extension box if we exceeded the box fill limitations. He then told me that that isn't legal because I didn't have anything (pipe/cable) going directly into the extension box. For years I have been installing extension boxes where box fill was an issue, without any problem what-so-ever.

I have looked it up and haven't found anything limiting my use of extension boxes to only when I need to use the knock outs in the extension box, but have I missed an exception somewhere?

 

[augie47]

AS others have stated, ther is no problem with using an extension purely for additional capacity.

 

[K_Buz]

#1 No.
#2 Free standing—seems it would need one. Please explain the install further.

We installed a subpanel to service 16 circuits and recepts for semi truck block heaters. The feeder pipe was directional bored 100' under the parking lot.


edit: I probably should mention that the underground feeder pipe was PVC and we did pull a seperate ground from the building's panel.

 

[resistance]

K_Buz, since you are new to the company, I want ask you to ask the person you was working with to provide a code reference—where it says an extension ring can only be used when conduit or some other piece of electrical equipment utilizes one or more of the KO’s. Seriously doubt this is a local code!!

 

[jumper]

We installed a subpanel to service 16 circuits and recepts for semi truck block heaters. The feeder pipe was directional bored 100' under the parking lot.


edit: I probably should mention that the underground feeder pipe was PVC and we did pull a seperate ground from the building's panel.

The separate EGC/ground was required, so is the GES/rods.

 

[LEO2854]

I piped in some switches in a commercial building and put a 4x4x2 1/8 box at the top of the wall for a pull point. The guy who was running the job was concerned that the box wouldn't be large enough. I told him that if anything we would just install an extension box if we exceeded the box fill limitations. He then told me that that isn't legal because I didn't have anything (pipe/cable) going directly into the extension box. For years I have been installing extension boxes where box fill was an issue, without any problem what-so-ever.

I have looked it up and haven't found anything limiting my use of extension boxes to only when I need to use the knock outs in the extension box, but have I missed an exception somewhere?

There is no reason you cannot use a extension ring,,,It sounds like the guy you are working with simply does not like them.


Welcome to the forum...:thumbsup:

 

[growler]

I told him that if anything we would just install an extension box if we exceeded the box fill limitations. He then told me that that isn't legal because I didn't have anything (pipe/cable) going directly into the extension box. For years I have been installing extension boxes where box fill was an issue, without any problem what-so-ever.

Normally it's not a good idea to run anything to the box extension, if it can be avoided. If you have to come back and do any further work in the box it's just easier to remove the extenion to see what you are doing and then replace it when finished.

What I found when working for several different companies over the years is that many people don't know the difference between code and job specs. If an electrician works on a job where something is not allowed ( say box extensions ) then they may get to thinking that it's code when in fact it may be just a design choice. They may not want extensions if there is lots of exposed work because they don't look that great.

Every electrician should own and carry a code book ( at least in their truck ). don't believe anyone until you see it for yourself.

 

[kwired]

I piped in some switches in a commercial building and put a 4x4x2 1/8 box at the top of the wall for a pull point. The guy who was running the job was concerned that the box wouldn't be large enough. I told him that if anything we would just install an extension box if we exceeded the box fill limitations. He then told me that that isn't legal because I didn't have anything (pipe/cable) going directly into the extension box. For years I have been installing extension boxes where box fill was an issue, without any problem what-so-ever.

I have looked it up and haven't found anything limiting my use of extension boxes to only when I need to use the knock outs in the extension box, but have I missed an exception somewhere?

One issue that could come up is if the length of free conductors in the box becomes too short because of an extension. This is actually a bigger problem if there is raceways coming out of the extension itself because the extension may no longer be removable to gain enough access to have minimum required free length.

I have run into this problem when there is a need to extend a box to make it a flush installation because they are furring the wall out. Especially a problem with one gang boxes that need extended.

 

[Twoskinsoneman]

One issue that could come up is if the length of free conductors in the box becomes too short because of an extension. This is actually a bigger problem if there is raceways coming out of the extension itself because the extension may no longer be removable to gain enough access to have minimum required free length.

I have run into this problem when there is a need to extend a box to make it a flush installation because they are furring the wall out. Especially a problem with one gang boxes that need extended.

I would overcome this enormous hurdle by slicing the too-short wire to another wire... Now it's long enough

 

[Rock Crusher]

I'll have to look up the code section, but I beleive you are required to have, at a minimum, 3" of wire exposed past the ring or box. With dimensions less than 8". If the box opening is 8" or greater, you are only required to have a minimum of 6" exposed from where it exits the conduit.
It's how I read it anyways.

300.14 Length of Free Conductors at Outlets, Junctions, and Switch Points

 

[Sierrasparky]

I'll have to look up the code section, but I beleive you are required to have, at a minimum, 3" of wire exposed past the ring or box. With dimensions less than 8". If the box opening is 8" or greater, you are only required to have a minimum of 6" exposed from where it exits the conduit.
It's how I read it anyways.

300.14 Length of Free Conductors at Outlets, Junctions, and Switch Points

agreed!

 

[infinity]

He then told me that that isn't legal because I didn't have anything (pipe/cable) going directly into the extension box. For years I have been installing extension boxes where box fill was an issue, without any problem what-so-ever.

This is another electricians urban legend. I was told this one over twenty years ago when I was an apprentice.

 

[WorkSafe]

What are the reactions or attitudes you guys are finding when you have to correct a coworker, boss, etc about a code "myth?" I would assume that person would feel pretty ignorant if they have been telling everyone it's 'code' for years when it never was 'code.' Do you find really stubborn people who will still believe it's code or not code when it's the opposite?

I figure the seasoned employee is more opt to correct someone, but someone who is new to the employer, like the OP, would be hesitant to correct someone?

 

[kwired]

What are the reactions or attitudes you guys are finding when you have to correct a coworker, boss, etc about a code "myth?" I would assume that person would feel pretty ignorant if they have been telling everyone it's 'code' for years when it never was 'code.' Do you find really stubborn people who will still believe it's code or not code when it's the opposite?

I figure the seasoned employee is more opt to correct someone, but someone who is new to the employer, like the OP, would be hesitant to correct someone?

If you are the new guy, and especially if you have less time in the trade, and find you seem to know more than your superiors, you better be looking for another job, because this one probably is not going to last. Some guys will listen and learn, many will just think they are not going to let the new guy know more than they do and will always give him a hard time. If you truly enjoy being in any trade, working with people you can't get along with will change that.