Hello!
As I live in VT, i am seeing many Canadian built modulars shipped in. I have noticed that the main panels isolate the service entrance conductors , they have a 2nd smaller cover that is seen after the first outer cover is removed.
I am wondering if this is coincidence , or is there a Candaian code that requires this???

Thanks
Steve >>aka sparky
Vermont Electrician

Hi Steve,

It's actually a CSA Standard that requires the manufacturers to have the main switch or circuit breaker located in a separate section of the enclosure.

Here's an excerpt from the applicable spec:

C22.2 No. 29-M1989
(Reaffirmed 2000)
Panelboards and Enclosed Panelboards

Industrial Products

7. Combination Service Entrance Panelboards
7.1 Scope
7.1.1
Clause 7 applies to panelboards rated at 600 V and less for service entrance use in nonhazardous locations in accordance with the rules of the Canadian Electrical Code, Part I.
7.1.2
Clause 7 applies to equipment in one enclosure that provides
(a) a service box; and
(b) a second compartment containing branch circuit overcurrent protection.
7.2 Definitions—See Clause 2.1.
7.3 General Requirements
General requirements applicable to this Clause are given in CSA Standard C22.2 No. 0, and Clause 3.
7.4 Construction
7.4.1 Service Box

7.4.1.1
The service switching means shall be manually operable with the box closed,* shall have no bare live parts exposed, and shall have overcurrent devices connected directly to such switching means.

*This does not exclude a construction where a decorative (nonmandatory) door covers the handles, provided that the opening of such a door does not allow access to wiring spaces.

7.4.1.2
The main switch or circuit breaker shall be located in a separate section of the enclosure and shall have a sheet-metal barrier, or the equivalent, of the same thickness as the walls of the enclosure; the barrier shall have bushed holes, or the equivalent, for the necessary wiring between compartments. Separate access covers and the means for sealing them shall be provided for compartments enclosing main switches or circuit breakers. The provision for sealing may be omitted where the main overcurrent device is rated 225 A or less and 250 V or less.


Tony Moscioni

Thank you Tony.
This is exactly what i am seeing. Even in 200A panels. It would seem CSA standards address the issue of 'Live Work' where our UL ( and other NRTL's) do not.

The jist of NFPA 70 E & subpart S could basically be stated as either shuting down, or in the cases where it cannot be, proper PPE to work on such, dictated by proximty, etc.....

As one can easily shut the main off here , the entrance conductors remain live to it,and exposed,,lacking the the simple isolation CSA addresses here.

We do not, per CSA example, put our NEMA $$$$ where our 'safety' mouths are......