Working Space

By Mar 15, 2007




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How to determine requirements—Part 1

The requirements in 110.26(A)(1) through (A)(3) of the National Electrical Code (NEC) deal with Code-prescribed “working space” at electrical equipment—requirements that in most instances are considered by designers, installers and inspectors as eyeball situations; however, the language in 110.26 and 110.26(A) needs special evaluation and careful consideration when working on energized exposed live parts that are either in compliance with or in violation of rules. This is dependant on the placement of and the amount of clear space surrounding the equipment. Determination of the proper installation for specific equipment should be based on the eventual maintenance or repair of the de-energized or energized exposed live parts of the equipment.

Spaces around electrical equipment

Section 110.26 has been in the NEC for at least 40 years, and most designers, contractors, installers and inspectors feel they truly understand the requirements. But, do they really?

Note that the term “equipment” defined in Article 100 is specifically related as a part of, or in connection with, an electrical installation. Therefore, some literally interpret this wording to mean clear work space applies to junction boxes, pull boxes, outlet boxes, convenience receptacles, wall switches, transformers, motors, relays, contactors, etc. Is this really practical in all cases and all types of installations? I don’t believe so.

Consider installations where there are no energized, exposed live parts to be worked on when maintenance or repair work is in progress. A good example is a junction box installed in an attic with no working space or clearance space required by 110.26(A) for proper installation.

This installation is acceptable because there are no exposed live parts to be worked on while energized. Circuits located in such a box are to be locked and tagged out as required by OSHA 1910 or 1926 standard and the NFPA 70E standard that deals with the safety of the electrician working in his or her work space.

What about a nonfusible disconnecting means or nonautomatic circuit breaker installed behind an air conditioner or motor. The same concept applies and work is not to be done if energized exposed live parts are present. A lockout and tagout procedure should be applied.

Please note the first sentence of 110.26 reads “Sufficient access and working space shall be provided and maintained about all electrical equipment to perform ready and safe operation and maintenance of such equipment.”

The junction box is a good example of insufficient access and working space (no energized exposed live parts). However, enough space is needed to examine a splice of conductors for appropriate continuity, etc. There are many other installations of equipment that fall under this concept.

Depth of working space

Depending on interpretation, one could argue the clearances described in 110.26(A) are only required where it is “likely” that “examination, adjustment, servicing, or maintenance” are necessary while the equipment is energized. The clear working space that is required by the first sentence as described in 110.26(A) may be eliminated only where examination, adjustment, servicing and maintenance are not “likely” to occur when energized exposed live parts, etc., are present.

The word “likely” is not defined in the NEC; therefore, when using the requirements of 110.26(A), the authority having jurisdiction (AHJ) has to determine the installation method ensures that the term “likely” is properly applied. The AHJ will usually require a written procedure to be developed, outlining the methods necessary to service the equipment de-energized, by the facility staff plus a warning label. The combination of the two provides proper balances and checks to warn electrical personnel when they are not permitted to work on specific equipment if energized with exposed live parts and/or conductors.

I realize that this may be viewed as extreme. However, if the designer, installer and inspector or AHJ can agree that the equipment will not be worked on when energized and is serviced under the prevailing conditions of the warning label and written procedures, such clearances are not mandatory. Considering that, there must still be amicable working space to work on equipment, including the replacement of components and the disassembly and removal of cover panels and doors as required by 110.26.

If the electrician does not apply the requirements in 110.26 and 110.26(A), there are many electrical equipment installations in all types of facilities that would fail to comply. Not only does proper working space promote safety, but it may alleviate potential problems associated with other types of access problems.          EC

STALLCUP is the CEO of Grayboy Inc., which develops and authors publications for the electrical industry and specializes in classroom training on the NEC, OSHA and other standards. Reach him at 817.581.2206.


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