Tapping off smoke alarm circuit allowed ?

[George Stolz]

110.8 Wiring Methods. Only wiring methods recognized
as suitable are included in this Code. The recognized methods
of wiring shall be permitted to be installed in any type
of building or occupancy, except as otherwise provided in
this Code.

I am unaware where 'tapping' into a interconnection of smoke detectors is ALLOWED.

I was unaware NM stopped being NM when installed between an arbitrary pair of appliances such as two smoke detectors.

 

[pjholguin]

Greetings,

I understand about tapping the BLK & WHT wires, and not the red wire. Do you coordinate which phase gets tapped?

NO!

You can tap into the black and white wire anywhere.

You can't tap into the red or yellow interconnect wire at all.

 

[mjf]

You feel the circuit conductors beyond the first smoke alarm are no longer a branch circuit?:huh:


Whatever you are smoking please share with me.

Wholeheartedly disagree.



Whatever he is smoking......please stop!!

 

[George Stolz]

Greetings,

I understand about tapping the BLK & WHT wires, and not the red wire. Do you coordinate which phase gets tapped?

Coordinate what? :blink:

 

[pjholguin]

When the smoke alarm sets, a signal voltage is sent down the red wire to the other smokes; can there be a possible short circuit if the smokes are on different phases?

Coordinate what? :blink:

 

[George Stolz]

When the smoke alarm sets, a signal voltage is sent down the red wire to the other smokes; can there be a possible short circuit if the smokes are on different phases?

Smokes are put all on the same circuit, because the red conductor has to be tied to all the smokes.

 

[John120/240]

Coordinate what? :blink:

When the smoke alarm sets, a signal voltage is sent down the red wire to the other smokes; can there be a possible short circuit if the smokes are on different phases?

pjholguin Coordinate What ? Make the circuit feeding the smokes a two wire (14-2 blk & wht) from the panel to the first detector. From first detector to 2nd, 3rd,..7th you would use a 14-3 blk & wht w/red for the interconnect. At a convenient spot say the 5th detector tap off for your Master Bed lights. Nowhere are we mixing phases.

 

[GoldDigger]

And to accommodate AC smokes with battery backup, the signal voltage on the red is almost certain to be a DC voltage with respect to the neutral. Which drives home the need to avoid crossing hot and neutral in any interconnection!

 

[pjholguin]

I understand how to wire the alarm circuit and my preference is to have only smoke/CO sensors on the circuit. The posts by mjf & buck don't sound like the alarms are the same circuits...that's how I read them.

pjholguin Coordinate What ? Make the circuit feeding the smokes a two wire (14-2 blk & wht) from the panel to the first detector. From first detector to 2nd, 3rd,..7th you would use a 14-3 blk & wht w/red for the interconnect. At a convenient spot say the 5th detector tap off for your Master Bed lights. Nowhere are we mixing phases.

 

[pjholguin]

If what you say is true, wouldn't there be a 725 violation? e.g. mixing control circuit classes: class 1 with class 2 or 3.

And to accommodate AC smokes with battery backup, the signal voltage on the red is almost certain to be a DC voltage with respect to the neutral. Which drives home the need to avoid crossing hot and neutral in any interconnection!

 

[ActionDave]

I understand how to wire the alarm circuit and my preference is to have only smoke/CO sensors on the circuit. The posts by mjf & buck don't sound like the alarms are the same circuits...that's how I read them.

The smokes are all on the same circuit. Said circuit is allowed to have other outlets on it; in some areas it is required.

 

[George Stolz]

If what you say is true, wouldn't there be a 725 violation? e.g. mixing control circuit classes: class 1 with class 2 or 3.

Not unless you can point at a class 2 or 3 power supply and/or a specific section violated.

 

[mjf]

I understand how to wire the alarm circuit and my preference is to have only smoke/CO sensors on the circuit. The posts by mjf & buck don't sound like the alarms are the same circuits...that's how I read them.

Sorry if I was not clear.

All smokes on 1 circuit. Also on that circuit (tied in at any point) is at least 1 general use receptacle or lighting outlet.


I like to put a lighting outlet or 2 that the HO will notice quickly if not working.

 

[pjholguin]

Thank you. Wouldn't the HO noticed once he turned off the breaker for smokes when the started beeping... never mind...my bad! :slaphead:

Sorry if I was not clear.

All smokes on 1 circuit. Also on that circuit (tied in at any point) is at least 1 general use receptacle or lighting outlet.


I like to put a lighting outlet or 2 that the HO will notice quickly if not working.

 

[GoldDigger]

They are clearly functionally related, so as long as the devices allow recategorizing to Class 1 there is no problem.

 

[pjholguin]

Kool Beans!

They are clearly functionally related, so as long as the devices allow recategorizing to Class 1 there is no problem.

 

[iwire]

They are clearly functionally related, so as long as the devices allow recategorizing to Class 1 there is no problem.

I have no idea at all what you are talking about. :?

 

[George Stolz]

If one were to assume the red conductor is a class 2 conductor (which we really can't do without seeing a class 2 power supply to reidentify as class 1) then Goldigger was clarifying any Chapter 3 wiring method can be used; and it could be in the same cable as the 120v conductors supplying the smokes.

Of course, the fact that the instructions take it for granted that we're gonna use three conductor cable doesn't hurt.

 

[iwire]

If one were to assume the red conductor is a class 2 conductor

Why the heck would we assume that?

This thread is getting stranger by minute.

 

[George Stolz]

Why the heck would we assume that?

This thread is getting stranger by minute.

Agreed on both counts.

We can't assume something is Class 2, we have to see the power supply.