# Town House Smoke Detector Circuit



## jar546 (Oct 17, 2014)

If you have a group of 5 town homes with common areas (site lighting, parking lighting, maintenance shed, etc) served by a house panel.  Can you have the smoke detector circuits in each town home served by branch circuits in the house panel and not the panel for that town home?


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## steveray (Oct 17, 2014)

Technically........No....Not by code......R314.4 Power source. Smoke alarms shall receive their primary power from the building wiring


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## cda (Oct 17, 2014)

And if I want to replace the smoke alarm in my unit  ,,, how do I know to go to the house panel to kill power?

Related is a disconnect for the smoke alarm required in each unit?? Not nec fleuant


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## jar546 (Oct 17, 2014)

I see opinions but no relevant code section prohibiting this.

R314.4 from building wiring.  It will be building wiring.


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## cda (Oct 17, 2014)

How about the disconnect issue????

Sorry not electrical inspector so not versed much in nec

Just makes since, not having to go to one house panel, so I can change the smoke alarm


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## jar546 (Oct 17, 2014)

So is this an IRC issue or an NEC issue or neither?

If this was planned in your community, what would you do?


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## cda (Oct 17, 2014)

Sounds like nec

Would question the submitter and talk to the BO about why it is not a good idea in a few ways.

Would you allow say the a/c circuit for all the units to be run off the house panel?? Or pick your circuit


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## Dennis (Oct 17, 2014)

Nec 210.25



> 210.25 branch circuits in buildings with more thanone occupancy.
> 
> (a) dwelling unit branch circuits. Branch circuits in
> 
> ...


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## cda (Oct 17, 2014)

"So it shall be written, so it shall be done!"


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## JBI (Oct 17, 2014)

By description in the IRC the walls separating Townhouses are 'Party Walls' (required ratings AND no openings, etc.).Since Party Walls are Fire Walls that occur on property lines, each Townhouse is on a separate lot and is a separate building. So Steveray's comment about receiving power from THE building wiring means each must receive power from its' own panel as each unit is a separate building.

Not sure there should be a 'common' anything...


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## Dennis (Oct 17, 2014)

JBI said:
			
		

> Not sure there should be a 'common' anything...


  If there are common areas such as outdoor stairways, rec rooms, outdoor lighting etc then a separate house panel would be needed.


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## jar546 (Oct 20, 2014)

Dennis said:
			
		

> Nec 210.25


But can a house panel for site lighting, etc. also supply the smoke detectors in the individual town homes?

I don't see where 210.25 applies because:

1)  210.25 (a) the dwelling unit circuits are only supplying loads to individual dwelling unit.

2)  210.25 (b) the dwelling units are not supplying the common areas because there is a separate "house" panel for the common areas.

I don't see where this would not be allowed………...


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## cda (Oct 20, 2014)

jar546 said:
			
		

> But can a house panel for site lighting, etc. also supply the smoke detectors in the individual town homes?I don't see where 210.25 applies because:
> 
> 1)  210.25 (a) the dwelling unit circuits are only supplying loads to individual dwelling unit.
> 
> ...


Maybe ask the question backwards

If the smoke alarm circuit and smoke alarm is in the unit

Does nec require a disconnect for that circuit I the unit ??? As supplied by the breaker box for that unit??

And also again would you think a person would know to go to the house/common area panel to kill power , in order to replace a smoke alarm???

Have you ever seen this set up before???


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## ICE (Oct 20, 2014)

> 210.25 Branch Circuits in Buildings with More Than
> 
> One Occupancy.
> 
> ...


The common areas can't be supplied from a panel that also supplies the dwelling unit branch circuits for smoke detectors.


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## Dennis (Oct 20, 2014)

jar546 said:
			
		

> But can a house panel for site lighting, etc. also supply the smoke detectors in the individual town homes?I don't see where 210.25 applies because:
> 
> 1)  210.25 (a) the dwelling unit circuits are only supplying loads to individual dwelling unit.
> 
> ...


I see this part



> _Branch circuits in __each dwelling unit shall supply only loads within that dwelling __unit or loads associated only with that dwelling unit._


  A branch circuit from a house panel would violate this IMO.  How can a house panel smoke detector circuit supply loads in any dwelling and also feed other dwellings without violating this part?


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## jar546 (Oct 20, 2014)

Dennis said:
			
		

> I see this part   A branch circuit from a house panel would violate this IMO.  How can a house panel smoke detector circuit supply loads in any dwelling and also feed other dwellings without violating this part?


That I can see and agree with.

If the wording said that "branch circuits ORIGINATING in…………." then we may have a problem.

Jeff


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## steveray (Oct 20, 2014)

R302.2 Townhouses. Each townhouse shall be considered a separate building.....And I don't believe townhouses typically have "common" anything.....Or they would be pushing the "R2 apartment" envelope....

R101.2 Scope. The provisions of the International Residential Code for One- and Two-family Dwellings shall apply to the construction, alteration, movement, enlargement, replacement, repair, equipment, use and occupancy, location, removal and demolition of detached one- and two-family dwellings and townhouses not more than three stories above grade plane in height with a SEPARATE means of egress


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## jar546 (Oct 21, 2014)

steveray said:
			
		

> R302.2 Townhouses. Each townhouse shall be considered a separate building.....And I don't believe townhouses typically have "common" anything.....Or they would be pushing the "R2 apartment" envelope....R101.2 Scope. The provisions of the International Residential Code for One- and Two-family Dwellings shall apply to the construction, alteration, movement, enlargement, replacement, repair, equipment, use and occupancy, location, removal and demolition of detached one- and two-family dwellings and townhouses not more than three stories above grade plane in height with a SEPARATE means of egress


Since a townhouse is considered a separate building, NEC 210.25 would not apply.

Hmmmm


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## mtlogcabin (Oct 21, 2014)

jar546 said:
			
		

> If you have a group of 5 town homes with common areas (site lighting, parking lighting, maintenance shed, etc) served by a house panel.  Can you have the smoke detector circuits in each town home served by branch circuits in the house panel and not the panel for that town home?


No

Not an electrician but follow the logic

How can the occupant access the disconnect to his smoke detectors?

The smoke detectors tied to a house panel are not being disconnected from the service entrance conductors as required by E3601.6.

E3601.6 Service disconnect required.

Means shall be provided to disconnect all conductors in a building or other structure from the service entrance conductors. NEC 230.7

E3601.6.2 Service disconnect location.

The service disconnecting means shall be installed at a readily accessible location either outside of a building or inside nearest the point of entrance of the service conductors. Service disconnecting means shall not be installed in bathrooms. Each occupant shall have access to the disconnect serving the dwelling unit in which they reside.


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## jar546 (Oct 21, 2014)

If there is a main service 600A disconnect to the townhouses and each of the panels are sub feeds of that main service, then there is a single disconnect that disconnects all conductors in a building.

I still don't see where this is not allowed.


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## Dennis (Oct 21, 2014)

jar546 said:
			
		

> If there is a main service 600A disconnect to the townhouses and each of the panels are sub feeds of that main service, then there is a single disconnect that disconnects all conductors in a building.I still don't see where this is not allowed.


That may be true but each building would need it's own disconnect and all disconnects for that structure must be grouped.  Now if you install a switch at every building for the smoke circuit it may be allowed per code but then I doubt you can install a smoke detector circuit on a switch other than the overcurrent protective device.


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## rnapier (Oct 21, 2014)

This section from NFPA 72 might apply.

29.5.2.2* Unless otherwise permitted by the authority having jurisdiction, audible fire alarm signals shall sound only in an individual dwelling unit, suite of rooms, or similar area and shall not be arranged to operate fire warning equipment or fire alarm systems outside these locations. Remote annunciation shall be permitted.

Generally you don't want one unit to ring in other

A.29.5.2.2 One of the common problems associated with smoke alarms and detectors is the nuisance alarms that are usually triggered by products of combustion from cooking, smoking, or other household particulates. While an alarm for such a condition is anticipated and tolerated by the occupant of a dwelling unit through routine living experience, the alarm is not permitted where it also sounds alarms in other dwelling units or in common use spaces. Nuisance alarms caused by cooking are a very common occurrence, and inspection authorities should be aware of the possible ramifications where the coverage is extended beyond the limits of the dwelling unit.


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## mtlogcabin (Oct 21, 2014)

jar546 said:
			
		

> If there is a main service 600A disconnect to the townhouses and each of the panels are sub feeds of that main service, then there is a single disconnect that disconnects all conductors in a building.I still don't see where this is not allowed.


Can't happen here as planning requires each "townhouse dwelling" to be on its on platted sub-lot of the parent lot. Utilities are not allowed to cross lot lines


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## jar546 (Oct 22, 2014)

mtlogcabin said:
			
		

> Can't happen here as planning requires each "townhouse dwelling" to be on its on platted sub-lot of the parent lot. Utilities are not allowed to cross lot lines


Interesting.  Most townhouse developments in our part of PA have the disconnects grouped on one of the end town homes and fed to the individual units via sub feed because the utility company refuses to run separate laterals.


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## jar546 (Oct 22, 2014)

Dennis said:
			
		

> That may be true but each building would need it's own disconnect and all disconnects for that structure must be grouped.  Now if you install a switch at every building for the smoke circuit it may be allowed per code but then I doubt you can install a smoke detector circuit on a switch other than the overcurrent protective device.


Each unit does, of course have it's own sub feed coming from the grouped disconnects.  The grouped disconnects are for feeders since there is already a service disconnect.

Still trying to see with this setup exactly where this is not allowed.


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## JBI (Oct 22, 2014)

Perhaps the term 'townhouse' is applied differently in different States? As mtlogcabin and I pointed out, in our respective locations there are property lines between the units. Lacking the property lines they are attached dwellings and outside the scope of the ResCode.


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## jar546 (Oct 22, 2014)

JBI said:
			
		

> Perhaps the term 'townhouse' is applied differently in different States? As mtlogcabin and I pointed out, in our respective locations there are property lines between the units. Lacking the property lines they are attached dwellings and outside the scope of the ResCode.


Townhouses are specifically listed in the IRC.


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## JBI (Oct 22, 2014)

I am aware Jeff. But by description they are on separate lots. The issue is traversing through neighboring properties with utilities, which is generally frowned on in some places.


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## cda (Oct 22, 2014)

jar546 said:
			
		

> Townhouses are specifically listed in the IRC.


I guess what is the purpose of this exercise???

It does not sound like a good set up, which normally means it does not meet code

Is someone trying to do this????


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## jar546 (Oct 22, 2014)

cda said:
			
		

> I guess what is the purpose of this exercise???It does not sound like a good set up, which normally means it does not meet code
> 
> Is someone trying to do this????


Yes, someone is trying to do this.  They want to build town homes (with sprinkler system of course) for a housing authority but this is what is planned.  We have asked them to re-evaluate their design from a practical and safety standpoint but still cannot find a code that applies prohibiting this.


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## Fort (Oct 22, 2014)

No, townhouses are not on separate lots by definition. They can be on the same lot per IRC. No need to keep fighting that fact.


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## Fort (Oct 22, 2014)

I don't see a code justification for rejecting it. But I also don't see why the applicant doesn't just do the smart and simple change and connect to circuit in the unit specific panel...


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## cda (Oct 22, 2014)

So if I live in one of these and find out the house is paying for my smoke alarm power

I hook a few electric outlets into that circuit and power my appliances off the smoke alarm circuit

And save a little electric power money!!!!!

NOW. , I like the set up


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## Dennis (Oct 22, 2014)

jar546 said:
			
		

> Each unit does, of course have it's own sub feed coming from the grouped disconnects.  The grouped disconnects are for feeders since there is already a service disconnect.Still trying to see with this setup exactly where this is not allowed.


art. 225.30 allows only one feeder or branch circuit to the building


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## Dennis (Oct 22, 2014)

Here is the article-- you need a lot of convincing...  I admit that it is convoluted but IMO it is a violation



> 225.30 Number of Supplies. A building or other structurethat is served by a branch circuit or feeder on the load side
> 
> of a service disconnecting means shall be supplied by only
> 
> ...


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## mtlogcabin (Oct 22, 2014)

Cabo required a property line between townhouse units. The IRC does not.

 Planning decided not to change there definition of a townhouse and the requirement of a property line between units.

I am glad they stuck to the original definition


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## JBI (Oct 23, 2014)

Fort, please read what I wrote not what you want it to say... I did not say by 'definition', I said by 'description'. Big difference. One gives you an answer, the other requires critical reading. I understand that different jurisdictions apply the Codes differently. In NYS Townhouses as regulated by the RCNYS *are *on separate lots. In any case, they are necessarily separate _buildings_. If designed as one building with more than 2 dwelling units it would again be outside the scope of the ResCode.


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## JBI (Oct 23, 2014)

Excerpts are from the 2010 RCNYS. I believe but could be mistaken that the IRC is essentially the same. It's describing a party wall.

*TOWNHOUSE.* A single-family dwelling unit constructed in a group of three or more attached units in which each unit extends from foundation to roof and with open space on at least two sides.

*R317.2 Townhouses.* Each townhouse shall be considered a separate building and shall be separated by fire-resistance-rated wall assemblies meeting the requirements of Section R302 for exterior walls.

*Exception:* A common 2-hour fire-resistance-rated wall is permitted for townhouses if such walls do not contain plumbing or mechanical equipment, ducts or vents in the cavity of the common wall. Electrical installations shall be installed in accordance with :Next('./st_ny_st_b400v10_33_par001.htm')'>Chapters 33 through :Next('./st_ny_st_b400v10_42_par001.htm')'>42. Penetrations of electrical outlet boxes shall be in accordance with Section R317.3.

*R317.2.1 Continuity.* The fire-resistance-rated wall or assembly separating townhouses shall be continuous from the foundation to the underside of the roof sheathing, deck or slab. The fire-resistance rating shall extend the full length of the wall or assembly, including wall extensions through and separating attached enclosed accessory structures.

*R317.2.2 Parapets.* Parapets constructed in accordance with Section R317.2.3 shall be constructed for townhouses as an extension of exterior walls or common walls in accordance with the following:1. Where roof surfaces adjacent to the wall or walls are at the same elevation, the parapet shall extend not less than 30 inches (762 mm) above the roof surfaces.2. Where roof surfaces adjacent to the wall or walls are at different elevations and the higher roof is not more than 30 inches (762 mm) above the lower roof, the parapet shall extend not less than 30 inches (762 mm) above the lower roof surface.

*Exception:* A parapet is not required in the two cases above when the roof is covered with a minimum class C roof covering, and the roof decking or sheathing is of noncombustible materials or approved fire-retardant-treated wood for a distance of 4 feet (1219 mm) on each side of the wall or walls, or one layer of 5/8-inch (15.9 mm) Type X gypsum board is installed directly beneath the roof decking or sheathing, supported by a minimum of nominal 2-inch (51 mm) ledgers attached to the sides of the roof framing members, for a minimum distance of 4 feet (1220 mm) on each side of the wall or walls.3. A parapet is not required where roof surfaces adjacent to the wall or walls are at different elevations and the higher roof is more than 30 inches (762 mm) above the lower roof. The common wall construction from the lower roof to the underside of the higher roof deck shall have not less than a 1-hour fire-resistence rating. The wall shall be rated for exposure from both sides.

*R317.2.3 Parapet construction.* Parapets shall have the same fire-resistance rating as that required for the supporting wall or walls. On any side adjacent to a roof surface, the parapet shall have noncombustible faces for the uppermost 18 inches (457 mm), to include counterflashing and coping materials. Where the roof slopes toward a parapet at slopes greater than two units vertical in 12 units horizontal (16.7-percent slope), the parapet shall extend to the same height as any portion of the roof within a distance of 3 feet (914 mm), but in no case shall the height be less than 30 inches (762 mm).

*R317.2.4 Structural independence.* Each individual townhouse shall be structurally independent.

*Exceptions:*1. Foundations supporting exterior walls or common walls.2. Structural roof and wall sheathing from each unit may fasten to the common wall framing.3. Nonstructural wall coverings.4. Flashing at termination of roof covering over common wall.5. Townhouses separated by a common 2-hour fire-resistance-rated wall as provided in Section R317.2.


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## Dennis (Oct 23, 2014)

So with all this info are there still members who believe the install is compliant.  I got lost in all the building code stuff.  It just doesn't seem safe to install it as stated.


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## cda (Oct 23, 2014)

Dennis said:
			
		

> So with all this info are there still members who believe the install is compliant.  I got lost in all the building code stuff.  It just doesn't seem safe to install it as stated.


I like it, if it was set up in my unit, I would tap in some electric outlets and run as many appliances off it as I could

Let my neighbors pay the electric bill


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## Dennis (Oct 23, 2014)

cda said:
			
		

> I like it, if it was set up in my unit, I would tap in some electric outlets and run as many appliances off it as I could Let my neighbors pay the electric bill


My sister in law owns an older condo and I noticed that when we turned all the power off there was one receptacle that was hot.  Apparently that got the wire on the wrong side of the party wall.  The owner would not let me in to fix it so I told her I would run a cord and let her pay for the refrigerator usage.  She got the management to deal with it.  They had reversed the outlets for those condo.  She could have done the same on her side....Been there 40 years


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## Paul Sweet (Oct 23, 2014)

As several posts have pointed out, you can have rental townhouses without property lines between them, or condominium townhouses where site lighting may be from a common panel, in addition to individually owned townhouses on separate lots.  The definition of townhouses doesn't say anything about property lines, unless your jurisdiction has very restrictive zoning laws.

Since each townhouse is considered as a separate building, and Dennis showed that a building can't be served by more than one feeder, running a feeder plus an additional circuit from the house panel violates the NEC.


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