5CCT Selectable Colour Temperature Explained

Selectable colour temperature raises one practical question on every job: the fixture can run at 2700K, 3000K, 3500K, 4000K or 5000K, so who picks, and when. A 5CCT fixture only ever runs at one setting at a time. Somebody has to choose, and the wrong time to find out nobody did is after the ceiling is closed and the client is standing under a row of potlights that do not match.

This guide covers how the switch works, when to set it, how to keep a whole job consistent, and why selectable fixtures have largely replaced stocking five separate SKUs. If you want a refresher on what the Kelvin numbers mean in a room, start with our guide to colour temperature from 2700K to 5000K.

How switch-selectable CCT works

A 5CCT fixture carries warm and cool LED channels on the same board. A small slide or DIP switch, usually on the back of the fixture or on the driver box, tells the driver which mix to run, and the mix lands on one of the five listed colour temperatures. It is a hardware setting. Set it once and the fixture holds that colour until someone physically moves the switch. There is no app, no controller and no special wiring.

That also means 5CCT is not tunable white. Tunable or smart fixtures change colour in operation through a control system. A selectable fixture behaves exactly like a fixed single-CCT unit once installed, including on dimmers. It dims like any other LED on a compatible dimmer, and the usual rules in our dimming compatibility guide apply unchanged.

Two spec-sheet details are worth a look before a big order. Some models rate slightly different lumen output at different settings, typically a small drop at the warmest position. And brands label the switch differently — some print Kelvin values, some print positions 1 through 5. Neither is a problem. Both are reasons to read the label before you set fifty of them.

Set the switch before the ceiling closes

On most slim panels and wafer-style potlights the switch sits on the back of the fixture or on the junction-box driver in the ceiling cavity. Once the fixture is up, reaching it means pulling the fixture back down. Spring-clip slim panels make that possible, but it is slow, and on some housings the switch faces the cavity where you cannot see it. Treat the setting as part of installation, not something to fix later.

The method:

• Decide per room at ordering or rough-in. Write the CCT for each area on the plan or the fixture schedule, the same way you note trim colour.
• Set every switch on the bench. Unbox, set, and mark the carton or the fixture. Setting switches on a ladder in a lit room is how mismatches happen.
• Power up and verify before closing. With all fixtures on at once, one wrong setting is obvious immediately. Checking fixtures one at a time, it is nearly invisible.
• Record the setting. A note in the closing documents or inside the panel door tells the next electrician what to match on a service call.

Keeping a job consistent

Mixing colour temperatures between rooms is normal. Warm settings in bedrooms and living areas, cooler settings in kitchens, garages and task areas — that is the point of a selectable fixture. Mixing within one room, or within one sightline down a hallway or across an open plan, is what reads as a mistake.

A few habits keep a job matched:

• Have one person set all the fixtures for a given space, in one sitting.
• Keep replacements and add-ons in the same model family. Two brands set to the same Kelvin number can still render slightly differently side by side.
• When a fixture is swapped under warranty, set the new one before it goes up, then check it against its neighbours with everything on.

Why one SKU beats five

Before selectable fixtures, covering 2700K through 5000K meant five versions of every size and trim. Five part numbers to order, five bins to stock in the van, and a return trip whenever the client's choice and the box on the shelf disagreed.

Selectable collapses that to one. The same case of fixtures covers a warm-spec custom home and a 5000K garage. Van stock always matches the job. When a client changes their mind at walkthrough, the fix is a screwdriver, not a return. And when a callback turns out to be "the lights feel too cold," it is a five-minute visit instead of a fixture swap.

The trade-off is small: a switch someone can leave in the wrong position, and the minor output variations noted above. The bench-setting method deals with the first, and the spec sheet deals with the second.

What to order

Most of our selectable stock lives in the LED potlights and slim panels collection, with adjustable-aim options under gimbal lights. Order one 5CCT SKU across the whole job, decide the settings room by room before install, and set the switches on the bench before the first fixture goes into the ceiling.

Check before you install. This guide summarises common practice to help you specify parts. The Ontario Building Code, the Ontario Fire Code and the Canadian Electrical Code are the authority, they are revised periodically, and your local authority having jurisdiction can be stricter. Confirm current requirements and have the work done by a licensed electrician.