Clearance Interpretation

[Dwight Whittaker]

There is a disrepancy within our office interpreting the code on clearances, 110.26. The code requires that all disconnects be readily accessible 404.8(A). Working clearance is maintained at a clearance of 36" for voltages below 600V. There is an exception in 404.8(A)EX. 2, which states that if a disconnect is installed adjacent to the piece of equipment being supplied it can be mounted over 6'7" for qualified personel (such as a VAV or an AHU mounted above an acustical tile ceiling). In the handbook 110.26(a) page 45, states,"likely to require examination, adjusting, servicing, or maintenance while energized." Within the explanation block it says the intent that says,"Minimum working clearances are not required if the equipment is such that it is not likely to require examination, adjusting, servicing, and maintenance while energized."

What clarifies the statement, "not like to require." A typical situation, a VAV or AHU mounted above the ceiling. The disconnect can be mounted adjacent to it but does it need 36" for working clearance. The disconnect, theoretically, doesn't require any type of servicing or maintenance except maybe to test voltages, tighten a loose connection or change a fuse. But these procedures are not typical servicing such as adjusting internal components of a piece of equipment.

So, in conclusion, can a disconnect be mounted adjacent to a piece of equipment an not have 36" deep and 30" wide clearances, since the disconnect is not likely to require servicing?

 

[charlie b]

What clarifies the statement, "not like to require."

I regret to say that nothing clarifies that statement. It is a question that is open to the interpretation of anyone and everyone, and it is common that the interpretation of the AHJ is the only one that counts. For my part, I agree with your statement that this disconnect isn't "likely" to require live work. But I am not the AHJ in your area (nor in any other area), so my agreement will not buy you anything.

 

[tom baker]

Lets use a motor as an example. Read the rules in 430.102. You need a disconnect for the motor and controller. One is required to be readily accessible and the other accessible. We want one readily accessible in case of an emergency. The other may be next to the motor or in an suspended ceiling, its for servicing the motor with out having to go back the other disconnect.

 

[bphgravity]

Along with several others:

1-105 Log #384 NEC-P01 Final Action: Reject
(110.26(A))
_____________________________________________________________
Submitter: Bryan P. Holland, Holland Electric

Recommendation: Revise text to read as follows:
Working space for equipment switchboards, panelboards, industrial control
panels, meter socket enclosures, and motor control centers operating at 600
volts, nominal, or less to ground and likely to require examination,
adjustments, servicing, or maintenance while energized shall comply with the
dimensions of 11 0.26(A)(1), (A)(2), and (A)(3) or as required or permitted
elsewhere in this code.

Substantiation: It should be made clear exactly what equipment requires
working space. This list mirrors the equipment identified in 110.16. The words
?likely to require? should be removed. Per Table 3.2.1 of NEC style manual,
?likely? is an unenforceable term. The words ?while energized? should be
removed. I believe the intent of this section is to provide adequate working
space for the safety of the worker and anyone using the equipment whether or not the equipment is energized. One could argue equipment is never ?required? to be energized.

Panel Meeting Action: Reject

Panel Statement: Creating a specific list of equipment that require working
space is too limiting. As proposed, there is no requirement that working space
be provided for equipment such as circuit breakers, fusible switches, control
panels, control assemblies and industrial control assemblies, to name a few.
Removing ?likely to require examination, adjustment, servicing, or maintenance while energized ? is over-restrictive. CMP-1 understands the
submitter?s concerns about the use of vague or unenforceable language. The
NEC Style Manual, however, recognizes and prefers the use of the term
?likely? over the term ?liable.? As an example, ?likely to become energized?
means ?failure of insulation on.? Although the NEC Style Manual discourages
the use of the term ?likely?, there are instances where the use is appropriate.
Number Eligible to Vote: 12
Ballot Results: Affirmative: 12