Lumex is a common brand name for NMD90 cable, the plastic-jacketed building wire used for branch circuits in dry, protected indoor locations. When someone says "Lumex wire" or "Lumex cable," they mean NMD90. It is the white, yellow or orange roll you see pulled through studs and joists for lighting, receptacles and small appliance circuits.
The name on the jacket is a brand. The cable type is what matters for inspection, for connectors and for the size you pick.
What is NMD90 wire?
NMD90 is a non-metallic sheathed cable made for Canadian building wiring. It holds copper conductors inside a plastic jacket, with a bare ground conductor running alongside them. The 90 in the name is the temperature rating of the conductors, 90 degrees Celsius. The jacket print shows the full CSA marking.
It comes as two-conductor cable, such as 14/2, and as three-conductor cable, such as 14/3, which adds a second insulated conductor for things like three-way switch loops. You can browse NMD and Lumex wire on our NMD and Lumex wire page.
What size NMD90 do you need?
The first number in the size is the conductor gauge. The second is how many current-carrying conductors are inside, not counting the bare ground. Common pairings on residential work:
- 14/2 for 15 amp lighting and receptacle circuits
- 12/2 for 20 amp circuits
- 10/2 for 30 amp circuits
- 14/3 for three-way switch loops
Those are typical uses, not a rule you can build to without checking. Confirm the size for your circuit with your electrician or against the current Canadian Electrical Code before you pull the wire. A 20 amp circuit, for example, is usually run in 12/2 copper, but the load, the run length and the breaker all factor in.
Jacket colours by gauge
Colour makes it easy to spot a gauge on site. In common Canadian practice:
- White for 14 gauge
- Yellow for 12 gauge
- Orange for 10 gauge
- Black for 8 and 6 gauge
Treat the colour as a fast visual check and confirm on the cable print itself. Print on the jacket carries the gauge, the conductor count and the temperature rating.
Where NMD90 is used, and where it is not
NMD90 belongs in dry, protected indoor locations: inside wall cavities, between joists, above ceilings, and behind finished surfaces in houses and small commercial spaces. It is not made for exposed outdoor runs, wet locations or direct burial.
For those jobs, match the cable to the location:
- Underground and wet locations call for NMWU. See our NMWU underground wires.
- Where the job calls for armoured cable or needs mechanical protection, ACWU or BX/AC90 is the usual choice. See ACWU wires and BX armoured wires.
- Edge cases, like a run through a garage, a crawlspace or a short exposed section, are worth a question to your inspector before you cut. Local interpretation varies.
NMD90, NMWU, ACWU and BX/AC90 side by side
| Cable | Construction in a few words | Typical use | Where it is not suited |
|---|---|---|---|
| NMD90 | Copper conductors, plastic jacket, bare ground | Dry indoor branch circuits in framing | Wet locations, exposed outdoor runs, direct burial |
| NMWU | Plastic jacket rated for wet locations | Underground runs, damp and wet spots | Where the spec calls for armoured protection |
| ACWU | Armoured cable with an overall jacket, rated for wet locations | Wet and underground locations where armoured protection is wanted | Jobs that call for a different armour type per spec |
| BX/AC90 | Flexible metal armour over conductors | Indoor runs that need mechanical protection | Wet locations, direct burial |
NMD90 vs TECK90, and ACWU vs TECK
TECK90 is a heavier armoured cable with an overall jacket, built for commercial and industrial work. It takes more abuse than NMD90 and suits plants, racks and mechanical rooms. Whether a given run needs TECK90 rather than NMD90 or BX is set by the project specification and your inspector, so read the spec before you order.
Can TECK cable be used indoors? Often yes, and it is regularly installed indoors in commercial and industrial buildings. The answer for your specific run depends on the location, the environment and the spec. Check with your inspector.
ACWU vs TECK comes down to the job. Both are armoured and both handle tough locations. ACWU is the common pick for wet and underground work. TECK90 is the heavier general armour for industrial installations.
BX cable vs NMD90
BX, also called AC90, wraps its conductors in a flexible metal jacket. That armour protects the cable from physical damage, which is why it shows up where a run is exposed or where someone could hit it. NMD90 relies on the building finish and framing for that protection, so it stays inside the wall.
If a cable is going to be visible and within reach, or if the spec calls for armoured cable, BX is the usual answer. If it is buried in a stud bay behind drywall, NMD90 is the standard choice.
Matching connectors and boxes
Use the connector made for the cable type. NMD connectors go with NMD90. BX connectors go with armoured cable. The connector and the box both have to match the cable size and type, so a 12/2 NMD90 needs a connector sized for that cable and a box with the right capacity for the conductors and the device.
Inspectors check connector and box fill on rough-in. Confirm the box fill and connector choice with your inspector if the run is unusual. Our NMD connectors collection lists connectors for plastic-jacketed cable.
FAQ
Is Lumex the same as NMD90?
Yes. Lumex is a brand name for NMD90 cable. Ask for NMD90 if you want the cable type rather than the brand.
What size wire for a 20 amp circuit?
12/2 copper is the usual choice for a 20 amp residential circuit. Confirm the final size with your electrician, since the load and run length matter.
Can TECK cable be used indoors?
It often is, especially in commercial and industrial buildings. Confirm the location and the spec with your inspector before you install.
What does the 90 in NMD90 mean?
It is the temperature rating of the conductors, 90 degrees Celsius. Check the print on the cable jacket for the full marking.
Need a hand matching cable, connectors and boxes for a job? Send us the details through our quote request page.
Sources
Check cable type and location against the current Canadian Electrical Code and with your inspector. Technical Safety BC: https://www.technicalsafetybc.ca/technologies/electrical