Electrical Panels in Closets and Bathrooms, a little walk in history.

Wenatchee Home Inspections Services.

Panelboards in closet, can they be there? This has been asked of me on several occasion and I knew that the requirement went back quite a ways.  First off the restriction really was about the overcurrent devices- fuses and breakers and not specifically panelboards. Since panelboards contain these devices they get included by association in the codes.

(Panel in closet)

Now for a few thoughts, the code specifies “easily ignitable materials”, but what does that really mean?

Ignitable materials from a hazardous materials perspective means having a flash point < 140°F. Well that is a pretty low number when we are talking about storage areas in homes or like. This would be items such as flammable liquids such as solvents and spent solvents (acetone, benzene, ethyl acetate, ethyl ether, methanol, methyl isobutyl ketone, xylene); ignitable paint waste etc…

From my reading and of my opinion I do not think this was the intent,  but the requirement was for items that could easily ignite from an electrical source when in close proximity to the OCPD. Later versions of the code clarify this as located in the vicinity of easily ignitible material “such as in clothes closets”.

Now cotton ignites  around 482°F and wool at  442°- 446°F. We all probably remember the book or movie Fahrenheit 451, that is the general temperature at which paper ignites.

Now Electrical arcing  is around 3750°C (6782°F) and an Electrical spark 1316°C (2400°F),  both of these temperature are well above the ignition point of common materials in a clothes closet. If these materials are in close proximity then they would in my opinion be easily ignitable.

Here is some later NEC handbooks comments that add some qualifiers in the notes.

From the 2002 NEC- Examples of locations where combustible materials may be stored are linen closets, paper storage closets, and clothes closets

19. Switches, Cut-outs, Circuit-breakers, Etc.

b. Must not be placed where exposed to mechanical injury or in the immediate vicinity of easily ignitable stuff or where exposed to in- flammable gases or dust, or flyings of combustible material. Where the occupancy of the buildIng is such that switches, cut-outs, etc., cannot be located so as not to be exposed as above, they must be mounted in approved cut-out boxes or cabinets, except oil switches, circuit-breakers  and similar devices which have approved casings. (See 35A for equipments in extra hazardous places. )

Cabinets and cut-out boxes must be of metal  when used with metal conduit, armored cable or metal raceway systems; for exceptions see  No. 40 c and 41 h 7.

NBFU 1933

806. General: Use of Overcurrent Devices (Automatic Overcurrent Protection).

g. Overcurrent devices shall not be placed  where exposed to mechanical injury nor in the vicinity of easily ignitable material. Except when mounted on switchboards or the equivalent which are located in approved rooms or fire- proof electric closets, overcurrent devices shall be enclosed in approved cabinets or cutout boxes. They shall, in all cases, be placed in readily accessible locations.

2435-  Location on Premise - Overcurrent protective devices shall be located where they will be readily accessible (except as provided in section 853 for busways and section 1850 for services), not exposed to mechanical injury and not in the vicinity of ignitible material.

NEC 1951

2435-  Location on Premise - Overcurrent protective devices shall be located where they will be;

(a) readily accessible except as provided in section 2573 for service equipment and 3650 for busways.

(b) not exposed to mechanical injury.

(c) Not in the vicinity of easily ignitible material.

NEC 1959,  we have a change in naming culture and new section

240-16-  Location on Premise - Overcurrent protective devices shall be located where they will be;

(a) readily accessible except as provided in section 230.91 for service equipment and 364-11 for busways.

(b) not exposed to physical damage.

(c) Not in the vicinity of easily ignitible material.

240-16-  Location on Premise - Overcurrent protective devices shall be located where they will be;

(a) readily accessible except as provided in section 230.91 for service equipment and 364-11 for busways.

(b) not exposed to physical damage.

(c) Not in the vicinity of easily ignitible material.

(d) Occupant to have Ready Access. Each occupant shall have a read access to all overcurrent devices protecting the conductor supplying the occupancy.

NEC 1975 (new code section)

240-24-  Location on Premise - Overcurrent protective devices shall be located where they will be;

(a) Readily Accessible.Overcurrent devices shall be readily accessible

exception 1 For services as provided as provided in section 230.91.

exception 2 For  busways as provided as provided in section 364-11.

exception 3 For supplementary overcurrent protection as provided as provided in section 240-10.

(b) Occupant to have Ready Access. Each occupant shall have a read access to all overcurrent devices protecting the conductor supplying the occupancy.

(c) Not exposed to physical damage. Overcurrent devices shall be located where they are will not exposed to physical damage.

(d) Not in the vicinity of easily ignitible material. Overcurrent devices shall not be located in the vicinity of easily ignitible material.

Then in the 1981 NEC  becomes the first edition that specifically mentioned clothes closets.

NEC 1981- 240.24 Location in or on Premises

(D) Not in Vicinity of Easily Ignitible Material -Overcurrent devices shall not be located in the vicinity of easily ignitible material, such as in clothes closets.

1993 NEC 240-24

(d) Not in Vicinity of Easily Ignitible Material. Overcurrent devices shall not be located in the vicinity of easily ignitible material, such as in clothes closets.

(e) Not Located in Bathrooms. In dwelling units and guest rooms of hotels and motels, branch-circuit overcurrent devices shall not be located in bathrooms as defined in Section 210-8.

In 1996 there was a slight variation of the bathroom restriction to allow “supplementary overcurrent protec­tion” (A “supplementary OCPD” provides limited overcurrent protection for specific applications and utilization equipment).

(d) Not in Vicinity of Easily Ignitible Material -Overcurrent devices shall not be located in the vicinity of easily ignitible material, such as in clothes closets.

(e) Not Located in Bathrooms. In dwelling units and guest rooms or guest suites of hotels and motels, overcur­rent devices, other than supplementary overcurrent protec­tion, shall not be located in bathrooms as defined in Article 100.

2008 NEC-  240.24 Location in or on Premises

(F) Not Located over Steps. Overcurrent devices shall not be located over steps of a stairway.

Well was that not fun. This gets us to pretty close to today’s requirements. There may be some slight variations here and there but that gives you a pretty good walk through the years.

“We are all born ignorant, but one must work hard to remain stupid.”

Benjamin Franklin

Your Wenatchee and Chelan Professional Real Estate, Home and Structural Pest Inspection Service

Instructor- Fundamentals of Home Inspection-  Bellingham Technical College

www.ncwhomeinspections.com                                                   509-670-9572

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