Quite often we look at the requirements of the CE Code without any concerns, as clarity of the literal text (and of the intent behind this text) appears to be obvious.

Rule 8-304 of the CE Code should be one of such clear requirements.

This Rule states the following:

“8-304 Maximum number of outlets per circuit

(1) There shall be not more than 12 outlets on any 2-wire branch circuit, except as permitted by other Rules of this Code.

(2) Such outlets shall be considered to be rated at not less than 1 A per outlet, except as permitted by Subrule (3).

(3) Where the connected load is known, the number of outlets shall be permitted to exceed 12, provided that the load current does not exceed 80% of the rating of the overcurrent device protecting the circuit.

(4) Where fixed multi-outlet assemblies are used, each 1.5 m or fraction thereof of each separate and continuous length shall be counted as one outlet, but in locations where a number of electrical appliances are likely to be used simultaneously, each 300 mm or fraction thereof shall be counted as one outlet.”

However, I recently witnessed a passionate discussion regarding Subrule (1), which allows up to 12 outlets to be on any 2-wire branch circuit, and the meaning of the word “outlet” has become a bone of contention in this animated discussion between the regulators, educators, electricians and electrical designers.

The “thorny” issue to interpret application of Rule 8-304(1) related to the situation when a duplex receptacle (or quad receptacle, see below) is “installed at the outlet” as per definition “receptacle”.

While I offered my interpretation of this Rule based on its literal text (and in my interpretation, I indicated that up to 12 outlets are allowed to be on a 2-wire branch circuit, regardless whether a single receptacle, a duplex receptacle or a quad receptacle is installed on the outlet), some participants in this discussion expressed a different viewpoint.

It should be noted that an outlet is defined in the Code as follows:

“Outlet — a point in the wiring installation at which current is taken to supply utilization equipment.”

The Code users with the different viewpoint invoked definition “receptacle” which states the following:

“Receptacle — one or more groups of female contacts, each group arranged in a configuration, all groups mounted on the same yoke and in the same housing, installed at an outlet and intended for the connection of one or more attachment plugs of a mating configuration.“

It should be also noted that the Code offers the following definitions of single, duplex and split receptacles:

“Duplex receptacle – a receptacle with two groups of female contacts.

  Single receptacle – a receptacle with one group of female contacts.

  Split receptacle – a receptacle with two or more groups of female contacts, having terminals adapted for  connection to one or more multi-wire branch circuits.”

These dissenting Code users stated that in a duplex receptacle there are two groups of female contacts intended for the connection of two attachment plugs to supply two pieces of utilization equipment, and if a duplex receptacle is installed at an outlet, then 12 duplex receptacles will be connected to a single 2-wire circuit, and as such:  24 pieces of utilization equipment could be supplied from such 2-wire branch circuit.

Respectively, when a quad receptacle is installed at an outlet, then there are four groups of female contacts intended for the connection of four attachment plugs – to supply four pieces of utilization equipment, and if 12 quad receptacles are connected to a single 2-wire circuit, then 48 pieces of utilization equipment could be supplied from such 2-wire branch circuit.

In light of this discussion, the following request for a consensus based interpretation by Section 8 S/C was submitted to the CSA:

Request for interpretation of Rule 8-304(1).

Request must be answered by a categorical “Yes” or “No”, based on the literal text of Rule 8-304(1).

The question: “Does Rule 8-304(1) apply to 12 outlets, where each of such outlets contains a receptacle with more than one group of female contacts, such as duplex or quad receptacles, and each such receptacle may accommodate more than one attachment plug intended for the connection of more than one piece of cord connected utilization equipment?”

Thus, interpretation provided by the S/C will be allowed to clarify the intent of this Rule, will improve consistency in application of this requirement, and will certainly improve safety of the CE Code.

It is intended by the submitted request for interpretation, that after the Technical Committee for the CE Code, Part I approves interpretation, the follow up clarification of this Rule in Appendix B Note will be introduced in order to remove any ambiguity from this subject matter for the benefit of the Code users.

Meanwhile, as usual, the local AHJ should be contacted, when any confusion arises with application of the CE Code requirements.

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Ark Tsisserev is president of EFS Engineering Solutions, Ltd., an electrical and fire safety consulting company, and is a registered professional engineer with a master’s degree in Electrical Engineering. Prior to becoming a consultant, Ark was an electrical safety regulator for the city of Vancouver. He is currently the chair of the Technical Committee for the Canadian Electrical Code and represents the CE Code Committee on the CMP-1 of the National Electrical Code. Ark can be reached by e-mail at: ark.tsisserev@efsengineering.ca His company web site is: http://www.efsengineering.ca

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