Pull Box, 36" x 36" w/480V motor branch circuit - Article 110.26 and T110.26(A)(1)

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Dale001289

Senior Member
Location
Georgia
Pull Box, 36" x 36" w/480V motor branch circuit - Article 110.26 and T110.26(A)(1)

I'm not sure how to call this one: in reviewing the plant this am, (under construction) I noticed a large, Nema 4X Stainless Steel enclosure, 36" x36" x 8" deep, installed between two units - the distance from the front of the Enclosure to the adjacent structure was less than 20 inches - hardly enough working space, even for a midget electrician.

After reviewing the drawings, I noticed the cable did not actually terminate within the enclosure, it was simply pulled through in a giant horseshoe loop - i.e. in the bottom/out the bottom.

This is horrible design, but is it a Code violation?
 

tkb

Senior Member
Location
MA
How is it a horrible design? Is this just that you wouldn't have done it this way?
You only need to be able to access the box and clearance dimensions don't apply.
 

Dale001289

Senior Member
Location
Georgia
How is it a horrible design? Is this just that you wouldn't have done it this way?
You only need to be able to access the box and clearance dimensions don't apply.
No offense intended about the 'midget electrician' part, if this applies to you:)Article 110.26 (2014 Handbook) clearly states "Access and working space shall be provided and maintained about all electrical equipment..."

Is the box NOT electrical equipment? Handbook says minimum 30" is needed for working space. I say this is a Code violation.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
No offense intended about the 'midget electrician' part, if this applies to you:)Article 110.26 (2014 Handbook) clearly states "Access and working space shall be provided and maintained about all electrical equipment..."

Is the box NOT electrical equipment? Handbook says minimum 30" is needed for working space. I say this is a Code violation.
its not electrical equipment that is likely to require examination, adjustment, servicing, or maintenance while energized.

otherwise, the requirement would apply to underground conduit, which would be rather impractical.

110.26 starts out by telling you working space is required, and then subsequent paragraphs tell you where it is required. take a close look at paragraph A.
 

iwire

Moderator
Staff member
Location
Massachusetts
Is the box NOT electrical equipment? Handbook says minimum 30" is needed for working space. I say this is a Code violation.
For sure the box is electrical equipment, the article 100 deffintion of equipment will confirm that.

But as Bob Peterson points out it is not likely to require examination, adjustment, servicing, or maintenance while energized which means the distances required for panelboards and the like do not apply to it.

Let me ask this, do you require the working space required by 110.26 for a conduit body or 4" square box used as a pull box?

Other then the large size what makes this pull box different?
 

Dale001289

Senior Member
Location
Georgia
For sure the box is electrical equipment, the article 100 deffintion of equipment will confirm that.

But as Bob Peterson points out it is not likely to require examination, adjustment, servicing, or maintenance while energized which means the distances required for panelboards and the like do not apply to it.

Let me ask this, do you require the working space required by 110.26 for a conduit body or 4" square box used as a pull box?

Other then the large size what makes this pull box different?

Philosophically, you're right, there is NO difference between a 4" square pull-box and 36" pull box. In practical terms however there's a world of difference. A 4" box is probably a pull or splice point for a lighting circuit - 120V or 208V. The other carries 480V to a three phase motor, and requires removal of the front panel with working space of around 18" to accomplish - see what I mean?
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Philosophically, you're right, there is NO difference between a 4" square pull-box and 36" pull box. In practical terms however there's a world of difference. A 4" box is probably a pull or splice point for a lighting circuit - 120V or 208V. The other carries 480V to a three phase motor, and requires removal of the front panel with working space of around 18" to accomplish - see what I mean?
According to your post:
After reviewing the drawings, I noticed the cable did not actually terminate within the enclosure, it was simply pulled through in a giant horseshoe loop - i.e. in the bottom/out the bottom.
Why would such an install require someone to work energized to repair a motor?
 

tkb

Senior Member
Location
MA
Philosophically, you're right, there is NO difference between a 4" square pull-box and 36" pull box. In practical terms however there's a world of difference. A 4" box is probably a pull or splice point for a lighting circuit - 120V or 208V. The other carries 480V to a three phase motor, and requires removal of the front panel with working space of around 18" to accomplish - see what I mean?
Why would a pull box require clearance since there is nothing that requires examination?
Just because it is larger than a 4" square doesn't mean there is a different rule, regardless of the system voltage.

If you are going to reject an installation then you need to back it with code and not opinion.
 

iwire

Moderator
Staff member
Location
Massachusetts
Philosophically, you're right,
It is not a philosophical question it is a code question and as far as the code in this case is concerned this large pull box is the same as a LB conduit body.

In practical terms however there's a world of difference. A 4" box is probably a pull or splice point for a lighting circuit - 120V or 208V.
I wire 480 volt and 277 volt circuits in 4" square boxes pretty often.

The other carries 480V to a three phase motor,
480 volt, 3 phase exhaust fans wired in standard size boxes.

Do they require the working space of an electrical panel?

and requires removal of the front panel with working space of around 18" to accomplish - see what I mean?
No I do not.


The code does not require the work be easy, only that it be possible.
 

Dale001289

Senior Member
Location
Georgia
It is not a philosophical question it is a code question and as far as the code in this case is concerned this large pull box is the same as a LB conduit body.



I wire 480 volt and 277 volt circuits in 4" square boxes pretty often.



480 volt, 3 phase exhaust fans wired in standard size boxes.

Do they require the working space of an electrical panel?



No I do not.


The code does not require the work be easy, only that it be possible.

I thought the Code required it to be safe - anything is possible.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I thought the Code required it to be safe - anything is possible.
I am not even sure the code requires it to be "possible". I don't recall ever seeing that requirement in the code.

In any case, "safe" is a very subjective term. There are things in the code to make an installation safe(r), but no where does the code require an installation be "safe" that I can recall.
 

charlie b

Moderator
Staff member
Location
Seattle, WA
Occupation
Electrical Engineer
In practical terms however there's a world of difference. A 4" box is probably a pull or splice point for a lighting circuit - 120V or 208V. The other carries 480V to a three phase motor, and requires removal of the front panel with working space of around 18" to accomplish - see what I mean?
For starters, why would you suggest that 120 volts is less dangerous than 480 volts? A person can be killed by 30 volts or even less. Secondly, what work would you think would have to be done to the wire that is inside this box? Why would anyone ever open the cover to this box? If you need to replace the wire inside the box, you will certainly turn off power to the wire. Since there are no terminations inside the box, you would never need to perform a thermography examination. I cannot conceive of a single circumstance in which would involve examination, adjustment, servicing, or maintenance while energized. Therefore, the working clearance requirements of 110.26 simply do not apply.

 

Dale001289

Senior Member
Location
Georgia
For starters, why would you suggest that 120 volts is less dangerous than 480 volts? A person can be killed by 30 volts or even less. Secondly, what work would you think would have to be done to the wire that is inside this box? Why would anyone ever open the cover to this box? If you need to replace the wire inside the box, you will certainly turn off power to the wire. Since there are no terminations inside the box, you would never need to perform a thermography examination. I cannot conceive of a single circumstance in which would involve examination, adjustment, servicing, or maintenance while energized. Therefore, the working clearance requirements of 110.26 simply do not apply.


All those on this string (other than myself, of course) have been brainwashed into thinking the NEC is a cut and dry set of rules - it is not, the NEC is, at least to some degree, abstract, requiring judgment, thought process, assessment and evaluation to determine what is and isn't safe. A few on this thread have attempted to throw-down the 'semantics card' - nope, that wont work either.
FYI - I have instructed the construction manager on this project to 'rip this installation to shreds' - i.e. start over and provide minimum 30" of frontal working space on the grounds it is inherently unsafe.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
All those on this string (other than myself, of course) have been brainwashed into thinking the NEC is a cut and dry set of rules - it is not, the NEC is, at least to some degree, abstract, requiring judgment, thought process, assessment and evaluation to determine what is and isn't safe. A few on this thread have attempted to throw-down the 'semantics card' - nope, that wont work either.
FYI - I have instructed the construction manager on this project to 'rip this installation to shreds' - i.e. start over and provide minimum 30" of frontal working space on the grounds it is inherently unsafe.
As long as you are footing the bill for it, I don't much care what you do.
 

oldsparky52

Senior Member
The way the contract is written, I have authority to make this call. Construction is required to make the change - on their own ticket.
It appears you are feeling indignant that no one supported your interpretation.

Now you are going to take it out on the construction guys? :happysad:

Is there an AHJ involved? If yes, what are they saying?
 

tkb

Senior Member
Location
MA
The way the contract is written, I have authority to make this call. Construction is required to make the change - on their own ticket.
If you tried this on one of my jobs, I would not be making the change until a change order was issued for the demo, redesign and rework.

Because you cannot back up your call with a code reference, you are using the "because I said so" rule.

This is is an abuse of your authority and you should reverse your decision.
 

Cow

Senior Member
Location
Eastern Oregon
It's disappointing to see someone throw their weight around to try and make a design change NOT required by the NEC no matter how much they try and read into it what they want the NEC to say.

Good luck with your project, I know from the projects that we do over here your attitude would not be well received on job sites.
 

ADub

Senior Member
Location
Midwest
Occupation
Electrician
Attitudes like this are usually the result of a mixture between lack of experience and an inflated sense of authority. I feel bad for the crew who has to deal with him but in my experience guys like this don't stick around too long


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