Fire alarm spliced in wall code

[Pinnie]

We have a situation where we put all single gang cut in boxes for sounder smoke bases that require four squares. The mounting holes don’t even allow double gang cut in boxes. The idea was thrown around to mount right to the drywall. Chat Gpt says it’s not a direct violation but it’s accuracy has a lot left to be desired. What do you guys think?

Pictured is a corrected version.

 

[roger]

There are 4" square old work box options, here's one example

 

[Pinnie]

There are 4" square old work box options, here's one example

That’s a good option! What does the NEC say about splicing fire alarm in the wall?

 

[infinity]

That’s a good option! What does the NEC say about splicing fire alarm in the wall?

It's spliced in a junction box or in the wall? Splices are allowed. In NYC we had to use 150° C rated wirenuts.

 

[Pinnie]

It's spliced in a junction box or in the wall? Splices are allowed. In NYC we had to use 150° C rated wirenuts.

Let’s say an accessible hole but no box. Like if you mounted a smoke right to the drywall without a box. My guess is it comes down to device instructions.

 

[roger]

See 760.53(A)(1)

 

[Pinnie]

See 760.53(A)(1)

“(1) In Raceways, Exposed on Ceilings or Sidewalls, or Fished in Concealed Spaces
Cable splices or terminations shall be made in listed fittings, boxes, enclosures, fire alarm devices, or utilization equipment. Where installed exposed, cables shall be adequately supported and installed in such a way that maximum protection against physical damage is afforded by building construction such as baseboards, door frames, ledges, and so forth.”

I would take this to mean if the device is listed for recessed termination, without a box/enclosure, then it would comply. Is that your interpretation?

 

[kwired]

In NYC we had to use 150° C rated wirenuts.

Why? Other than someone in authority thought it needed to assert their misguided opinion?

An alarm is likely initiated before the connection would ever reach that temperature. The connection itself shouldn't carry enough current to get that hot if a bad connection. If the connection does go bad for whatever reason, the zone supervisory function should issue a trouble alert.

 

[roger]

I would take this to mean if the device is listed for recessed termination, without a box/enclosure, then it would comply. Is that your interpretation?

If you can find a listed device with that wording of course.

 

[Pinnie]

If you can find a listed device with that wording of course.

Which is unlikely for most devices. Gotcha thank you!

 

[gadfly56]

Which is unlikely for most devices. Gotcha thank you!

If you're a fan of System Sensor 2W-B conventional smoke detectors, they are listed for direct attachment to the ceiling. In that case, your "splice" at the detector is code compliant. Otherwise, if you have a hand hole, replace it with a 4" cut in box and cover plate.

 

[hbiss]

We have a situation where we put all single gang cut in boxes for sounder smoke bases that require four squares. The mounting holes don’t even allow double gang cut in boxes. The idea was thrown around to mount right to the drywall. Chat Gpt says it’s not a direct violation but it’s accuracy has a lot left to be desired. What do you guys think?

Pictured is a corrected version.

Very few devices will mount directly to a 4 square (or a 4 11/16") box directly. There are any number of plates that they are to be used with them to mount devices and fixtures.

You might want to try this with those cut-in 4" squares to mount the smokes-

Double gang cut-in boxes are to be used with two receptacles and/or switches. Not fixtures.

-Hal

 

[Pinnie]

Very few devices will mount directly to a 4 square (or a 4 11/16") box directly. There are any number of plates that they are to be used with them to mount devices and fixtures.

Very true. this is why they were not installed. First time I’ve seen four square only fire alarm devices. Usually we mount single gang cut ins or octagons for smokes.

 

[hbiss]

Those two elongated holes are for mounting to a 4" round box or ring such as what I posted above. The hub goes through the plate into the box.

-Hal

 

[Pinnie]

Those two elongated holes are for mounting to a 4" round box or ring such as what I posted above. The hub goes through the plate into the box.

-Hal

I’m struggling to see the benefit as opposed to mounting directly to a 4 square.

 

[letgomywago]

I’m struggling to see the benefit as opposed to mounting directly to a 4 square.

It helps keep a clean finish in drywall or a ceiling tile.

 

[hbiss]

I’m struggling to see the benefit as opposed to mounting directly to a 4 square.

According to those instructions you just posted, it is indeed supposed to mount directly to the box. But I also believe you when you say that there are no holes that line up with the ears to allow it. It has to be made to mount to the box somehow. Maybe they changed the design? I would find a 4" round box, a 4" round raised ring or whatever you can come up with that has screws with that dimension just to see if it fits, because that's the most usual way. Then you can get what you need for the boxes that you have.

-Hal

 

[jmellc]

There are 4" square old work box options, here's one example

View attachment 2576468

Don't think I've see a factory box like this. I've jerryrigged a few. Good they're available.

 

[kwired]

I’m struggling to see the benefit as opposed to mounting directly to a 4 square.

You could use a round cut in box instead of the 1 gang cut in boxes you mentioned in OP that it won't work with?

 

[Pinnie]

You could use a round cut in box instead of the 1 gang cut in boxes you mentioned in OP that it won't work with?

True!