In an unfortunate incident, the plastic plug for one of my A/C-powered smoke detectors became detached from the wires coming out of the ceiling. My ceiling now looks like so (click for full size):


The detached connector:


My question is: how can I safely reconnect the plug? Can I just stuff the wires back into their respective holes in the plastic connector? And, if I turn off main power to my house in my the circuit breaker box, that should be sufficient to ensure that I do not electrocute myself, correct?

  • A photo of the broken part would be useful (and might invalidate the first part of my answer). – Niall C. Dec 1 '11 at 6:07
  • @NiallC.: Ah, I suppose that would help :-S. I'd be okay with replacing it, but even if I do that, I still have live wires coming out of my ceiling, and I'm not sure what to do to connect everything together safely. I guess if I bought a new one and mounted it it might have installation instructions, though... or I suppose I could just get a battery powered one and cap off the wires... – James McNellis Dec 1 '11 at 6:27
  • If you look through the hole in the ceiling you can see the electrical nuts that connect the detector's wires to the house wiring; they'll screw off, leaving the wires which should be twisted together. Use pliers to untwist them and you'll be good to install the new detector. Turning off the whole house is overkill; the circuit should be labeled at the service panel – Niall C. Dec 1 '11 at 6:43
  • With the red wire coming down I would almost bet you have another detector in the house and they could be inter-connected, meaning if one goes off then the other(s) will too. You might have to replace it with one of the same brand for the interconnection which might be code. Is the accident where you used the smokie to time your cooking?:) That's how my wife does it. – lqlarry Dec 1 '11 at 6:43
  • @NiallC.: /facepalm. Oh, I understand now... I didn't realize the wires coming out of the ceiling were really part of the in-ceiling fixture. I'll just buy a new one then. That sounds easiest. – James McNellis Dec 1 '11 at 6:52

I don't think you can. I can't say for sure without seeing the part that the wires pulled out of, but I'd expect that originally those wires were soldered to a terminal block, then that terminal block was sealed inside the (probably sonically welded) plug. Without opening the plug to re-solder those wires, you won't get a secure connection.

TL;DR: Don't mess with it; just replace it. Smoke detectors are not that expensive and it's better to have a new one that you can rely on than one that's been broken and repaired.

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    Also, more and more states are requiring carbon monoxide detectors in any single family, multiple family that has either gas hookups to the structure or and attached garage. Now you can buy combo units (smoke and carbon monoxide) and stay on top of the law. – lqlarry Dec 1 '11 at 6:36
  • Thank you; I hadn't even realized that the ceiling fixture was removable as well! – James McNellis Dec 1 '11 at 6:55
  • From the pictures the plastic disk looks like it is just a housing for crimped terminals on the wires, which are still intact and could be simply inserted back into the housing. (I'm assuming the disk is supposed to hold the wires on the ceiling for a plug-in connection to the detector itself, not pictured.) However, being ripped out might likely have damaged the parts which hold the terminals in place. – Kevin Reid Dec 1 '11 at 15:17

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