Where’s the Common Sense? HVAC dwelling unit systems in the 2023 NEC

By Mark C. Ode | May 15, 2023
Changes in the 2023 National Electrical Code dealing with heating and air conditioning equipment make me a bit skeptical about what is happening in the electrical and building industries. I wonder why public inputs and comments were necessary to put this information into the NEC when common sense would have sufficed.

Changes in the 2023 National Electrical Code dealing with heating and air conditioning equipment make me a bit skeptical about what is happening in the electrical and building industries. I wonder why public inputs and comments were necessary to put this information into the NEC when common sense would have sufficed.

It’s all text to me

Maybe I am old enough to remember when workmanship and pride of installation would have been reasons to keep these issues to a minimum without having to put them in the NEC. On the other hand, maybe I am not seeing the full picture of what is happening in the industry.

The introductory text in 110.12, covering mechanical execution of work, has been changed from requiring “electrical equipment to be installed in a neat and workmanlike manner” to “electrical equipment shall be installed in a professional and skillful manner.” Maybe the change in this section was to delete the word “workmanship” as being too gender-specific. However, the definition in Webster’s Dictionary of “workmanship” is expressed as “the quality of a piece work” and in another dictionary as “the degree of skill with which a product is made, or a job is done.”

The phrase “neat and workmanlike manner” has been in the NEC since before the 1971 edition and for at least as many years as I have been dealing with it. Change is good, but if there is no reason for it, it is unnecessary. I don’t believe anyone has questioned the reasoning for requiring a neat and workmanlike manner, but I guess it could be in the eye of the beholder.

Changes in 440

New text has been inserted into 440.8, dealing with an air conditioning or refrigerating system and its location. It states that this equipment is considered to be a single machine under the provisions of 430.87 Exception No. 1 and 430.112, Exception (both dealing with a number of motors in a group served by a single controller). These group motors are permitted to be located remotely and still be considered “group” since they comply with two references mentioned above.

In the 2023 NEC, 440.8’s title was changed by adding the word “location.” Text was also added to deal with restricting this equipment from a specific location within the building, which reads as follows: “Air-conditioning and refrigeration equipment must not be installed within a zone measured 900 mm (3 feet) horizontally and 2.5 m (8 feet) vertically from the top of a bathtub rim or shower stall threshold. The zone shall be all-encompassing and include the space directly over the tub or shower stall.”

The first revision statement of problem and substantiation for not permitting the split mini-HVAC evaporator units in the zone or space directly over the tub or shower space was that the unit should not be within 8 feet vertically from the top of the bathtub rim or shower stall threshold and should not be within 3 feet horizontally. 

The public input compared the split unit HVAC to other electrical equipment that is not permitted in these areas, such as switches, receptacles and ceiling-suspended luminaires. None of those examples provided in the substantiation are anywhere close to the same as a split unit evaporator unit.

The Panel’s statement was that, due to lack of space in small bathrooms, this could be a hazard. There wasn’t any technical substantiation or a history of problems, just that it could present one. There wasn’t a comment made on this first revision by anyone.

It would be nice to have some real investigation into the safety issue associated with this system before restricting it in the NEC. I am sure that servicing the split unit with the bathtub full would be a safety issue, but that would certainly be something no one in their right mind would do anyway.

Disconnecting means

I also noticed a change in 440.11. The general requirements in this section are applicable to all of Part II of Article 440. The added text is as follows: “If the disconnecting means is readily accessible to unqualified persons, any enclosure door or hinged cover of a disconnecting means enclosure that exposes energized parts when open shall require a tool to open or be capable of being locked.” 

Most fusible, nonfusible or other types of disconnecting means are already manufactured with and have had provisions to lock the door.

This does not say that a lock must be applied, but that it must have provisions to lock the door. 

What is considered to be readily accessible to unqualified persons? Better check it out for liability purposes as an electrical contractor!

Header image: shutterstock / VectorMine

About The Author

ODE is a retired lead engineering instructor at Underwriters Laboratories and is owner of Southwest Electrical Training and Consulting. Contact him at 919.949.2576 and [email protected]





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