Town House Smoke Detector Circuit

[jar546]

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?

 

[steveray]

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

 

[cda]

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

 

[jar546]

I see opinions but no relevant code section prohibiting this.

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

 

[cda]

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

 

[jar546]

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

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

 

[cda]

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

 

[Dennis]

Nec 210.25

210.25 branch circuits in buildings with more thanone occupancy.

(a) dwelling unit branch circuits. Branch circuits in

each dwelling unit shall supply only loads within that dwelling

unit or loads associated only with that dwelling unit.

(b) common area branch circuits. Branch circuits installed

for the purpose of lighting, central alarm, signal, communications,

or other purposes for public or common areas of

a two-family dwelling, a multifamily dwelling, or a multioccupancy

building shall not be supplied from equipment that

supplies an individual dwelling unit or tenant space.

 

[cda]

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

 

[JBI]

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...

 

[Dennis]

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.

 

[jar546]

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………...

 

[cda]

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………...

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???

 

[ICE]

210.25 Branch Circuits in Buildings with More Than

One Occupancy.

(B) Common Area Branch Circuits. Branch circuits

required for the purpose of lighting, central alarm, signal,

communications, or other needs for public or common areas

of a two-family dwelling, a multifamily dwelling, or a multioccupancy

building shall not be supplied from equipment

that supplies an individual dwelling unit or tenant space.

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

 

[Dennis]

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………...

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?

 

[jar546]

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

 

[steveray]

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

 

[jar546]

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

 

[mtlogcabin]

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.

 

[jar546]

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.

 

[Dennis]

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.

 

[rnapier]

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.

 

[mtlogcabin]

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

 

[jar546]

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.