full disclosure here. you may be looking at a product that is similar looking but fundamentally different than what i think it is.
what you are looking at is a bulkhead light for furniture only. meant to be used inside a cabinet box or some other structure that is classed in the NBC as "furniture". even though many places sell these, you cannot legally use these for potlighting where they are submerged into a drywall ceiling, even I have seen these installed so many times in the wrong way. its disturbing. you cannot just cut a hole and clip these into the hole. I have worked on multiple different residences where these have caught fire outright or been smouldering when they were turned off finally.
1) there is no way to connect to the unit in a way that makes the connection compliant with the OEC. the connections have to be in a metal enclosure, and these don't come with it. I have seen every type of disturbingly mis-thought arrangement with these things.
2) the fire code requires that any penetration into the rooms fire barrier (the drywall ceiling) must be in an appropriately fire rated enclosure. since these have a power supply board either onboard or in a little separate module (with a molex connector usually), that part also has to be installed in an approved enclosure.
3) even if you want to do all your connections in an approved rework pot or some other device, they are a weird diameter that doesn't match any pots that I have ever seen.
4) ESA will not pass these in any installation I have ever seen, and I have had inspectors tell me that ESA is still working on getting the legislative clout to have them banned outright, so that they can't be sold at all in Canada without the aforementioned warnings. just remember that you can run electrical cable through a drain line, but its not legal. caveat emptor.
do yourself a favour and get led refit assemblies from cree or greenlite. I buy them by the skid from greenlite for about $15 ea. they are not that much more if you buy just a case of them. they have a 5 year warranty, honoured by a Canadian company, and they are bombproof, commercial grade lights.
http://www.greenlite.ca/en/lights/1895-led-10w-dimmable-retrofit-kit-4-.html
The rules for box fill are contained in NEC 314.16(B). Generally, if you are using 14 AWG wire, you need 2 inches of space for
- each power carrying (hot and neutral) wire
- all ground wires counted as one
- internal cable clamps (usually in metal boxes) counted as one (external clamps and built-in clamps on a plastic box don't count)
- hickeys or other light fitting devices count as one
- each strap containing a device (a duplex outlet or double switch count as one)
If the wire is 12 AWG, all figures are increased to 2.25.
If you do the math and your box has too many wires, including any you need to add, you need either a bigger box or a second box.
If appearance isn't an issue, you can get box extenders that protrude from the front and add inches.
Depending on how the wires feed into the box, you maybe able to add another box a few inches to one side or the other, removing a few circuits from the original box, terminating them in the new, and just connecting the live feed between the old and new.
Best Answer
No, that's very unlikely to work, even if you do manage to find another one with the same connector.
The box you're looking at is not just a junction box, it's also the power supply for the LEDs - and it's specific to the type and number of LEDs in the fixture.