What Are Connectors?

Connectors are fittings used to secure cable where it enters a box, cabinet, panel, disconnect, device box or other enclosure. Their job is to provide strain relief, mechanical retention and, depending on the cable type, bonding continuity and environmental sealing. In this category, connectors are commonly selected for Teck cable, NMD90 cable and AC90 armoured cable. Teck connectors are built to grip and terminate armoured cable with an outer jacket. AC90 connectors are intended for armoured cable without the same jacket construction as Teck. NMD90 connectors are used for non-metallic sheathed cable and are generally much simpler, but they still need to match the cable size and box entry correctly.

Where Are Connectors Used?

These connectors are used across residential, commercial, industrial and light institutional work. NMD90 connectors are common in wood-frame residential construction, suites, small commercial tenant work and branch circuit rough-in. AC90 connectors are common in commercial interiors, suspended ceiling spaces, service rooms and retrofit work where armoured cable is preferred. Teck connectors are widely used in industrial facilities, rooftop equipment feeds, outdoor runs, mechanical rooms, service entrances, pump systems and areas where a tougher cable assembly is needed. The application matters because dry indoor branch-circuit work may only need a basic connector, while outdoor or washdown areas may require a sealing connector and a more careful match to cable jacket diameter.

How To Choose Connectors

Start with the cable family: Teck, AC90 and NMD90 each need a connector designed for that cable construction. Next, verify the actual cable size range the fitting accepts. For armoured cable, the armour profile and outer jacket diameter matter more than a casual label such as 2C or 3C. Then confirm the enclosure entry size, usually by knockout trade size. After that, look at the environment: dry indoor, damp, outdoor, corrosive or washdown. Also check whether the installation needs a straight connector, 90 deg style, insulated throat, sealing ring, locknut, bonding bushing or other accessory. For maintenance and retrofit work, matching the existing fitting style can reduce labour if the enclosure layout is tight or if cable replacement has to fit an established entry pattern.

Trade Rules Of Thumb

A practical rule of thumb is to size the connector from the cable outside diameter and the fitting maker's cable range, not from conductor ampacity tables. Another useful rule is that Teck and AC90 are not interchangeable just because both are armoured. Teck usually needs a connector intended for jacketed armoured cable, while AC90 fittings are made for that armour style and termination method. For NMD90, avoid assuming one connector fits every 2-conductor and 3-conductor cable of the same gauge because sheath thickness and cable profile can vary. In panel and enclosure work, it is also good practice to think about wrench clearance and cable bend space before choosing a large straight fitting. These are practical buying rules only. Final selection and installation should always follow the applicable product instructions and Canadian code requirements.

Sizing Guidelines

Connector sizing is typically driven by three checks: cable acceptance range, knockout trade size and enclosure wall thickness or hub compatibility where relevant. For Teck and AC90, use the actual cable catalogue data or field-measured outside diameter if there is any doubt. For NMD90, confirm the connector is listed for the cable size and number of cables if more than one cable is permitted in the fitting. If the connector lands in a standard knockout, make sure the trade size matches the box or cabinet opening. If reducers, enlargers or sealing washers are needed, account for them before ordering. As a rule of thumb, if the cable only barely enters the fitting or the gland components do not seat cleanly, the size is probably wrong. Do not force a near-match. Connector sizing and installation must be verified against the fitting manufacturer's instructions and the applicable Canadian Electrical Code requirements.

Common Installation Practices

Installers commonly prep the cable first, then dry-fit the connector components before final make-up. For Teck, that usually means careful jacket removal, armour preparation and correct assembly of the gland or clamping parts so the cable is retained without damaging conductors or insulation. For AC90, common practice is to cut armour cleanly, protect conductor insulation at the termination and ensure the fitting is fully seated and bonded as intended. For NMD90, installers typically secure the cable with the correct sheath length inside the box and avoid over-tightening clamps that can damage the jacket. Across all cable types, common good practice includes using the proper locknut or sealing hardware, maintaining conductor protection at the entry point and checking that the cable is supported independently rather than hanging on the connector alone where that would be inappropriate.

Common Mistakes

The most common mistake is ordering by cable name only and skipping the actual diameter range. Another frequent problem is mixing up Teck and AC90 fittings because both involve armour. Electricians also run into trouble when they choose the right cable fit but the wrong knockout size, or when they forget that a wet or outdoor location may need a sealing arrangement. On NMD90 jobs, a common error is using a connector that pinches the sheath too aggressively or does not suit the number of cables entering the box. In retrofit work, buyers sometimes focus on unit price and miss labour cost: a cheaper fitting that is awkward to assemble in a crowded cabinet can cost more in the field. Inspection issues often come from poor cable prep, incomplete locknut tightening, missing bonding details or using a connector outside its intended cable range.

Brand Comparisons

Brand choice in connectors usually comes down to fit consistency, ease of assembly, availability and whether the fitting matches the installed base on the project. On many jobs, matching an existing connector family can make maintenance and replacement easier because crews already know the make-up method and accessory parts. Some brands are cross-shopped mainly on price for standard dry-location work, while others may be preferred when installers want more predictable assembly on armoured cable or better sealing options for tougher environments. Since brand availability can vary by project and branch stock, many buyers choose first by cable compatibility and fitting style, then compare lead time and field familiarity. If you are replacing existing fittings in a plant or commercial building, staying with the same style may be the lowest-risk option. If you are buying for new work, a comparable alternative can be suitable if the cable range, listing and installation method all align.

Related Products

Connectors are usually purchased alongside locknuts, sealing washers, bonding bushings, reducing washers, box connectors, cable straps, support hardware and the cable itself. For Teck work, related items often include glands, sealing accessories, cable cleats and industrial enclosures. For AC90 installations, common related products include armoured cable, boxes, device rings and support fittings. For NMD90 rough-in, buyers often add boxes, staples, loomex cable, bushings and rough-in accessories. If the connector lands in a panel, disconnect or junction box, it is worth checking enclosure knockout sizes and wall thickness before finalizing the order so the fitting package is complete on the first delivery.

Frequently Asked Questions

Can I use the same connector for Teck and AC90?

Usually no. Even though both are armoured cable types, the connector must be designed for the specific cable construction and size range. Always verify the fitting is intended for that cable family and actual outside diameter.

How do I size a connector correctly?

Use the connector manufacturer's accepted cable range and match it to the actual cable outside diameter, then confirm the knockout trade size. Do not size from conductor ampacity or conductor gauge alone.

Are NMD90 connectors different from armoured cable connectors?

Yes. NMD90 connectors are intended for non-metallic sheathed cable and generally clamp the sheath differently. Armoured cable connectors for AC90 or Teck are built to terminate armour and, in some cases, provide bonding and sealing functions.

When do I need a sealing connector?

Sealing connectors are commonly considered where moisture, dust or outdoor exposure matters, or where enclosure integrity is important. The exact requirement depends on the location, enclosure type and product listing, so confirm the application details before ordering.

Why does cable outside diameter matter so much?

Because the connector grips the cable body, jacket or armour profile, not just the conductor inside. Two cables with similar conductor counts can have different outside diameters, and a poor fit can lead to weak retention, difficult assembly or inspection issues.

Is a cheaper connector always fine for standard work?

Not always. On simple dry indoor jobs, lower-cost fittings may be acceptable if they match the cable and installation. But on repetitive commercial or industrial work, easier make-up, better fit consistency and fewer call-backs can outweigh a small unit-price difference.