How to Wire Multiple Recessed Lights Together?

Wiring multiple recessed lights together is the difference between a professional-looking pot-light install and a maintenance headache that shows up years later. Done right, every fixture turns on together, off together, and dims together on a single switch. Done wrong, one bulb failure kills the whole row, or the last fixture in line runs dim while the first one runs bright. This guide walks GTA homeowners through how to wire multiple recessed lights together safely, to Ontario Electrical Safety Code, with the branch-count and load-per-fixture rules that decide whether the run is homeowner-permitted work.

Wire recessed lights in parallel, not in series

Direct answer: every recessed light on a single circuit gets a black lead to the branch hot, a white lead to the branch neutral, and a green or bare lead to the equipment bond — all in parallel. Do not wire fixtures in series (where the neutral leaves one fixture and enters the next as a switched hot). A parallel connection means one bulb failure has no effect on the rest of the row.

The simplest way to picture a parallel run: think of each fixture as a branch off a spine. The 14/2 cable enters the fixture’s junction box, splices to the fixture leads with marrettes, and continues out the other side of the box to the next fixture. Every joint is inside the fixture’s built-in junction box — no buried splices, which is a Section 12 requirement of the Ontario Electrical Safety Code.

How many recessed lights can you put on one circuit?

Direct answer: with modern integrated LED pot lights drawing 9-15 W each, a single 15 A branch circuit can safely carry 60-80 fixtures on a continuous load basis under the OESC 80% derating rule. In practice, most Ontario homeowners top out at 24-30 fixtures per circuit before adding a second run for panel-side balancing.

• 15 A / 120 V circuit: 1440 W continuous. At 12 W per LED fixture, that is 120 lights on paper — practically capped at 24-30 by run length and voltage drop.
• Old halogen pot lights (50 W each): 8-10 fixtures maximum per 15 A circuit under the same derating rule.
• Mixed fixtures on one circuit: not recommended — different bulb types have different starting currents and different dimmer requirements.

Voltage drop is the practical limit on a long residential run. A 14 AWG copper conductor loses about 2.5 V per 30 metres at 15 A. Once total drop exceeds 3% of nominal voltage, LED drivers can start to misbehave on dimmer transitions. For runs longer than about 25 metres, step up to 12 AWG on a 20 A circuit — permit territory in Ontario, and licensed-electrician work.

Step-by-step: connect a row of pot lights

1. Plan the layout first — our post on installing recessed lighting in an existing ceiling covers spacing and joist-avoidance rules.
2. Kill the breaker feeding the branch you plan to extend and verify dead at every fixture location.
3. Pull 14/2 NMD-90 cable from the branch feed junction box (or the wall switch) to the first fixture. Leave a service loop of 8-10 inches at each fixture.
4. Continue 14/2 cable from the first fixture’s junction box to the second, from the second to the third, and so on. Each junction box has two cable entries — one in, one out.
5. At each fixture, twist all the black conductors (incoming, outgoing, and fixture lead) together under one marrette. Do the same with the whites and the bares. Fixture is in parallel.
6. Bond every metal box and every fixture yoke to the bare copper equipment bond — no exceptions.
7. Fold conductors carefully into each junction box before pushing the fixture up into the ceiling.
8. Terminate at the switch box — our single-pole switch guide covers the terminal connections for a plain switch, and our safe dimmer guide covers a dimmed run.
9. File an ESA Homeowner Wiring Notification before you re-energize. Adding fixtures and running new branch cable is not maintenance — it needs a permit and inspection.
10. Restore power and confirm every fixture turns on and dims together with no flicker.

Dimmable multi-fixture runs

Direct answer: if the run is on a dimmer, every fixture must be dimmable-rated and must use the same brand and model. Mixing brands or dimmable/non-dimmable fixtures causes flicker and audible buzz. The dimmer must be LED-rated with a total wattage rating equal to or greater than the sum of all fixtures on the circuit.

Because LED drivers can create inrush currents, derate the dimmer to about 50% of its marked capacity for LED loads. A 600 W dimmer running 24 x 12 W LED pot lights (288 W) is at 48% of rating — comfortable. The same dimmer running 60 fixtures would be over-loaded. Our post on LED dimmer flicker covers the derating math when the run has trouble.

Common wiring mistakes

Direct answer: the four mistakes we correct most often on service calls are (1) daisy-chaining the neutral through the fixture instead of parallel-splicing, (2) skipping the equipment bond at one fixture in the row, (3) mixing dimmable and non-dimmable fixtures, and (4) exceeding the box-fill rule at a fixture with three cables entering.

Section 12 of the Ontario Electrical Safety Code governs box fill, and every fixture’s junction box has a printed maximum conductor count on its label. Two cables in and out with a fixture lead is usually the safe maximum on a standard pot-light housing. The Electrical Safety Authority writes up over-full boxes and missing bonds as recurring issues on residential permit inspections — do not skip either.

Expert tip from our ESA-licensed electricians

In our experience wiring long runs of pot lights across GTA renovations, the single detail that saves us the most callback time is drawing the full daisy-chain path on paper before we cut a single hole. Marking which fixture is fed first, which is fed last, and where the run splits or bends means we never have to trace a wire back through insulation once the drywall goes up. Homeowners who wire in the moment often end up with a fixture that got missed in the chain and shows up dark on final testing — fixing it means opening a completed ceiling. Fifteen minutes of paper planning saves an hour of drywall repair.

Related reading from ezsmart.ca

• How to install recessed lighting in an existing ceiling?
• How to Install a Dimmer Switch Safely?
• Why do my LED lights flicker when I use the dimmer?
• How to Change a Single-Pole Light Switch?
• Pot Light Installation Willowdale

Contact us

Planning a multi-fixture pot light run in your GTA home and want an ESA-certified electrician to design, wire, and permit it? Call us at 416-838-9006 or visit our contact page — we will get back to you the same day.