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CSA C22.2 No. 118-1959 (2013) – Pull-out and Junction Boxes: Technical Requirements and Compliance
A Comprehensive Guide to the Canadian Standard for Electrical Junction and Pull-out Boxes under the CE Code, Part II
CSA C22.2 No. 118-1959 (R2013) is a cornerstone standard within the Canadian Electrical Code (CE Code) Part II series. It establishes the safety requirements for pull-out boxes and junction boxes intended for ordinary locations. First published in 1959 and reaffirmed in 2013, this standard continues to govern the design, construction, and performance of these essential wiring enclosures used across residential, commercial, and industrial installations in Canada.
Scope and Application
CSA C22.2 No. 118-1959 (R2013) covers two main categories of enclosures:
- Pull-out boxes – boxes that serve as disconnecting means for circuits, typically employing a pull-out mechanism to open or close the circuit.
- Junction boxes – boxes used for splicing, tapping, or connecting conductors, providing accessibility while protecting wiring from mechanical damage and environmental factors.
These boxes are intended to be installed in accordance with the CE Code Part I (CSA C22.1) in ordinary (non-hazardous) locations. The standard does not apply to boxes rated for hazardous locations (covered separately by CSA C22.2 No. 30 and No. 159), nor to special-purpose enclosures such as those for swimming pools or outdoor panelboards. All products covered by this standard must be certified by a recognized certification body (e.g., CSA, UL, Intertek) as meeting its requirements before being marketed or installed in Canada.
Technical Requirements
Construction and Materials
Pull-out and junction boxes must be constructed from suitable metallic or nonmetallic materials that provide adequate strength, corrosion resistance, and electrical continuity. Metallic boxes typically use steel (galvanized or zinc-coated) or die-cast aluminum, while nonmetallic boxes are moulded from thermoset or thermoplastic materials meeting flame‑class and impact resistance criteria.
Dimensions and Knockouts
The standard prescribes minimum internal dimensions and knockout sizes to ensure adequate wiring space and compatibility with conduit and connectors. Table 1 summarizes key requirements.
| Requirement | Metallic Boxes | Nonmetallic Boxes |
|---|---|---|
| Material thickness (minimum) | 1.35 mm (0.053 in) for steel; 1.5 mm (0.059 in) for aluminum | ≥1.5 mm (0.059 in) at any point |
| Knockout sizes (nominal trade sizes) | ½, ¾, 1, 1¼, 1½, 2 in. (must be easily removable without distorting the box) | Same as metallic; concentric or eccentric knockouts permitted |
| Minimum internal depth | 13 mm (0.5 in) for boxes with covers smaller than 100 x 50 mm | 13 mm (0.5 in) |
| Grounding means | Bonding screw or provision for grounding pigtail (bonding continuity must be maintained between box and cover) | Not required (nonmetallic boxes are non‑conductive; grounding is ensured through the wiring method) |
| Corrosion protection | Galvanized, zinc‑plated, or painted with corrosion‑resistant finish | Inherently corrosion‑resistant; no additional protection needed |
Mechanical and Electrical Tests
Manufacturers must subject representative samples to a series of tests to verify compliance:
- Strength and impact test – A 6.8 kg steel ball dropped from 0.6 m onto the box shall not cause cracks or permanent deformation that reduces internal space.
- Grounding continuity test – For metallic boxes, the resistance between the box and any removable cover must not exceed 0.1 Ω after installation of the bonding means.
- Dielectric voltage-withstand test – 1000 V plus twice the rated voltage (minimum 1500 V) applied between live parts and the box, without breakdown or flashover.
- Temperature rise test – Under rated current conditions, the temperature rise on any external surface must not exceed 30 °C above ambient.
Marking Requirements
Each box must be permanently marked with:
- Manufacturer’s name or trademark
- Type designation (e.g., pull-out or junction box)
- Electrical ratings (voltage and current, where applicable)
- Number and size of knockouts
- Certification mark (e.g., CSA or cCSAus)
Tip: When replacing knockouts, always use the painted or galvanized finish matched to the box material to maintain corrosion resistance. For nonmetallic boxes, ensure that the knockout is cleanly removed without cracking the adjacent material.
Implementation Highlights
For manufacturers and specifiers, implementing CSA C22.2 No. 118‑1959 (R2013) involves the following key considerations:
- Design verification: Prototypes must pass the mechanical and electrical tests listed above. Obtaining a CSA certification certificate requires submission of test reports and a factory inspection.
- Factory production control: Ongoing quality assurance must include periodic checks of material thickness, knockout removal force, and grounding continuity on a sampling basis.
- Installation compliance: The Canadian Electrical Code Part I (CSA C22.1) requires that all boxes be accessible after installation. Pull-out boxes must be installed so that the pull-out mechanism is readily operable, and conductor fill rules (as per Table 2 of the CE Code) must be observed to avoid heat buildup.
Warning: Using a box that does not bear a recognized certification mark voids the installation’s compliance with the CE Code Part I. Always specify boxes marked with the appropriate certification agency’s logo that includes the standard number (e.g., cCSAus).
Many pull-out boxes covered by this standard are used in service entrance equipment or as disconnect switches for motors and appliances. Junction boxes serve as pull points for cables, as splice boxes, or as device boxes (e.g., switches or receptacles) when provided with appropriate mounting provisions. The standard is harmonized in principle with UL 50 (Enclosures for Electrical Equipment) but differs in specific dimensions and testing procedures; therefore, dual‑marked products are common for the North American market.
Compliance Notes
The 2013 reaffirmation of this 1959 standard signifies that no technical modifications were made, but the standard was reviewed and remains current. Users must be aware of the following compliance aspects:
Impact of the Reaffirmation
Because the standard was reaffirmed without change, all products certified to earlier editions (e.g., 1959, 1972, or 1993) are still deemed compliant provided they meet the original requirements—provided they were marked accordingly. However, regulatory authorities (e.g., provincial inspection bodies) may require boxes to be listed to the latest edition of the standard. It is recommended to always specify products certified to the reaffirmed version (R2013).
Field Evaluation and Alterations
Modified boxes (e.g., adding custom knockouts or mounting holes) may void certification. In such cases, the box must be re‑evaluated by a certification body or replaced with listed products. Pull‑out mechanisms containing fusible or switching elements may need additional compliance with CSA C22.2 No. 29 (Service Boxes) if used as service disconnects.
Interaction with Other Standards
This standard complements but does not replace:
- CSA C22.2 No. 18 – Outlet boxes, conduit boxes, and fittings (for smaller boxes).
- CSA C22.2 No. 29 – Service boxes (for service entrance equipment).
- CSA C22.2 No. 94 – Special purpose enclosures (for outdoor or corrosive environments).
When a box is intended for both pull‑out and junction functions, it must meet the more stringent of the applicable clauses.
Good Practice: Always consult the latest edition of the CE Code Part I and provincial amendments for installation requirements. Many jurisdictions require that pull‑out boxes be marked with their ampere rating and voltage, and that junction boxes be provided with adequate capacity for the number of conductors they contain.
Danger: Do not use pull‑out or junction boxes covered by this standard in hazardous (classified) locations. Such applications require boxes certified to CSA C22.2 No. 30 (Explosion‑Proof Enclosures) or CSA C22.2 No. 159 (Intrinsically Safe Equipment). Using a standard box in a hazardous area creates a serious ignition risk.
Q: What is the significance of the “(R2013)” designation in the standard number?
A: It stands for “Reaffirmed 2013”. The standard was reviewed and declared technologically sound without the need for changes. The original 1959 edition remains applicable; no new technical requirements were introduced. If the standard had been revised, it would be designated “CSA C22.2 No. 118‑2013”. The reaffirmation ensures continued recognition under the CE Code.
A: It stands for “Reaffirmed 2013”. The standard was reviewed and declared technologically sound without the need for changes. The original 1959 edition remains applicable; no new technical requirements were introduced. If the standard had been revised, it would be designated “CSA C22.2 No. 118‑2013”. The reaffirmation ensures continued recognition under the CE Code.
Q: Can a junction box certified to CSA C22.2 No. 118 also be used as a pull‑out box?
A: Only if the box is specifically designed and tested for pull‑out service and is so marked. A junction box alone does not contain a disconnecting mechanism; to function as a pull‑out box it must incorporate switching or fusible components that meet the additional requirements for interrupting capacity, overcurrent protection, and accessibility. Check the manufacturer’s listing to confirm the intended use.
A: Only if the box is specifically designed and tested for pull‑out service and is so marked. A junction box alone does not contain a disconnecting mechanism; to function as a pull‑out box it must incorporate switching or fusible components that meet the additional requirements for interrupting capacity, overcurrent protection, and accessibility. Check the manufacturer’s listing to confirm the intended use.
Q: Are nonmetallic boxes acceptable under this standard?
A: Yes, provided they meet the same mechanical and flammability requirements as metallic boxes. Nonmetallic boxes are commonly used in residential applications for switches and receptacles. They must be marked “NONMETALLIC” and are permitted for all ordinary‑location installations, subject to CE Code rules on support, conductor fill, and grounding.
A: Yes, provided they meet the same mechanical and flammability requirements as metallic boxes. Nonmetallic boxes are commonly used in residential applications for switches and receptacles. They must be marked “NONMETALLIC” and are permitted for all ordinary‑location installations, subject to CE Code rules on support, conductor fill, and grounding.
Q: How does this standard relate to the Canadian Electrical Code Part I?
A: CSA C22.2 No. 118 is referenced in CE Code Part I (CSA C22.1) as a prescriptive standard for box construction. Section 12 of the CE Code specifies installation rules, including box fill calculations, support, and accessibility. Compliance with both the product standard and the installation standard is required for a fully code‑compliant system.
A: CSA C22.2 No. 118 is referenced in CE Code Part I (CSA C22.1) as a prescriptive standard for box construction. Section 12 of the CE Code specifies installation rules, including box fill calculations, support, and accessibility. Compliance with both the product standard and the installation standard is required for a fully code‑compliant system.
This technical article was prepared for informational purposes and reflects the understanding of CSA C22.2 No.118‑1959 (R2013) as of 2026. Always refer to the official standard text and consult with a certified electrical engineer for specific application requirements.