Lumin installers in Canada often raise concerns about a Canadian Electrical Code prohibition on making splices in an electrical panel. This restriction generally does not apply to Lumin installations, as demonstrated in this document.

Note: In the U.S., the connection between two conductors is typically called a splice. In Canada, this connection is often called a joint. These two terms may be used interchangeably in this document and have the same meaning. 


The following is Lumin's good-faith interpretation of the code. The ultimate decision always rests with the local electrical inspection authority. Installers with doubts about this interpretation are encouraged to discuss it with their inspector before commencing work. 


These are the commonly cited restrictions in the Canadian Electrical Code, 2021 edition:


6-212 
1) Enclosures for circuit breakers and externally operated switches shall not be used as junction boxes, troughs, or raceways for conductors feeding through or tapping off to other apparatus.

2) Notwithstanding Subrule 1), service equipment designed for accommodating current monitoring devices or other associated electrical equipment that must, for its operation, be connected to the line side of the service disconnecting means, shall be permitted.


3) Consumer’s service conductors that enter a service box that is not equipped with a barrier between the line and load sides shall
a) enter the service box as close as possible to the line terminals of the main switch or circuit breaker; and
b) not come into contact with or cross conductors connected to the load terminals of the main switch or circuit breaker.


Strict Interpretation: Section 6 only pertains to services and service boxes; See 12-3032 for panelboards. Splices may not be permitted if there is no service disconnect on the supply side of the circuit breaker enclosure. Inspectors in some areas may reject any installation with a wire nut/marrette in a service box. Note that in solar and storage installations the Microgrid Interconnect Device (MID) (Tesla Gateway, Enphase IQ System Combiner, etc) typically contains a breaker that becomes the service disconnect between the meter and circuit breaker enclosure. When wired this way, the circuit breaker enclosure is no longer a service box, and 6-212 does not apply.

Moderate Interpretation: This section only pertains to services and service boxes. See 12-3032 for panelboards. All splices are extending existing wiring that terminates in the enclosure. Therefore, this is not a raceway use. A Lumin Smart Panel installation does not involve conductors feeding through the enclosure (conductors coming from somewhere else and going to somewhere else). A Lumin Smart Panel installation does not involve conductors tapping off to other apparatus (with the possible exception of the Lumin Grid Detection Circuit, which is explicitly permitted to be connected to the line side of a service in Subrule 2). A Lumin Smart Panel installation involves using the enclosure as a junction box, but it is a permitted use as the spliced conductors are not feed-through or tap conductors prohibited by Subrule 1. 


12-3032 
(1) Enclosures for overcurrent devices, controllers, and externally operated switches shall not be used as junction boxes, troughs, or raceways for conductors feeding through to other apparatus.


(2) Notwithstanding Subrule (1),
(a) the enclosures identified shall be permitted to be used as junction boxes
(i) for all installations where a single feeder supplying another enclosure is tapped from it and the connectors used each provide an independent clamping means for each conductor and each clamping means is independently accessible for tightening or inspection; or
(ii) where wiring is being added to an enclosure forming part of an existing installation and the conductors, splices, and taps do not fill the wiring space at any cross-section to more than 75% of the cross-sectional area of the space; and
(b) the enclosure identified shall be permitted to be used as a raceway where the conductors are being added to enclosures forming part of an existing installation and all conductors present do not fill the wiring space at any cross-section to more than 40% of the cross-sectional area of the space.


Interpretation: Section 12 applies to panelboards that are not service boxes (circuit breaker enclosures that do not contain the service disconnect). 

Typically, Lumin Smart Panel wiring is simply an extension of existing wiring that forms part of an existing installation; no loads are being added to the jointed/spliced wiring. If new loads are being added to the panelboard and managed by Lumin, it may be necessary to splice those loads in a junction box external to the panelboard.

Some authorities may interpret a Lumin Smart Panel installation as using the panelboard as a raceway since a conductor is routed from the breaker into the Lumin Smart Panel, back into the panelboard (where it is spliced), and then onward to the load. Such raceway use is allowed by Subrule 2(b). However, this is not a true raceway application as the spliced conductor terminates in the same enclosure. See the simplified diagram at the bottom of this page for an example.

Installers must take care to ensure that they do not violate the 75% maximum fill requirement.

From the CEC handbook, clarifying 12-3032(1):
When wiring is required to be added to an existing installation, Subrule (2) allows the existing enclosures to be used as junction boxes or as raceways, provided that the conductors, splices, and taps do not fill the cross-sectional area of the space to more than 75% and that conductors run through the enclosure do not fill the wiring space at any cross-section to more than 40% of the cross-sectional area of the space. This exception recognizes the need for the installation of management systems and other similar upgrades that tap into the existing wiring system for monitoring purposes, etc. Apart from the single feeder tap in Subrule 2(a)(i), this exception applies to existing installations only and is not an acceptable practice for new installations in which the design can incorporate the required enclosures for the wiring systems.


Simplified Lumin Smart Panel wiring schematic: