FA Power

[Alwayslearningelec]

Looking for a little code clarity on 2 hour protections/survivability for fire alarm equipment(DGP’s/FCO). Is there a code section that’s specific as to what portion of the run needs to be 2 hour protected or if it even has to be? I understand there are different ways to achieve this e.g. 2 hour rated room, MI cable, Vitalink cable etc.

This is specific to NYC.

Sometimes the drawings call show RGS and not a 2 hour cable/assembly. Thanks.

 

[infinity]

What are the loads coming out of the top of your drawing, various risers to feed DGP's and other F/A panels?

The #6 SSBJ between the transformer and the disconnect switch is too small, for 600 kcmil it should be #1/0. Also the 400 amp EGC to the panel should be a minimum of #3 copper.

 

[Alwayslearningelec]

What are the loads coming out of the top of your drawing, various risers to feed DGP's and other F/A panels?

The #6 SSBJ between the transformer and the disconnect switch is too small, for 600 kcmil it should be #1/0. Also the 400 amp EGC to the panel should be a minimum of #3 copper.

Yes.

 

[gadfly56]

Looking for a little code clarity on 2 hour protections/survivability for fire alarm equipment(DGP’s/FCO). Is there a code section that’s specific as to what portion of the run needs to be 2 hour protected or if it even has to be? I understand there are different ways to achieve this e.g. 2 hour rated room, MI cable, Vitalink cable etc.

This is specific to NYC.

Sometimes the drawings call show RGS and not a 2 hour cable/assembly. Thanks.

Well, the engineer already told you in the drawing note how to do this. MI cable. If you check through the NYC building code at Appendix Q and the electrical code, you'll find that you need to run from the generator to the ATS to the load with 2-hour protected cable, but NOT from the primary service to the ATS.

 

[infinity]

Where does it say that the conduit feeding a DGP or other fire alarm panel needs to be 2 hour rated?

 

[Alwayslearningelec]

Where does it say that the conduit feeding a DGP or other fire alarm panel needs to be 2 hour rated?

See pic..

 

[infinity]

See pic..

Maybe someone can post the NFPA72 section that applies but we never have used a 2 hour rated system for DGP risers.

 

[Alwayslearningelec]

Maybe someone can post the NFPA72 section that applies but we never have used a 2 hour rated system for DGP risers.

MAybe you ran in an 2 hour rated closet.

 

[gadfly56]

Maybe someone can post the NFPA72 section that applies but we never have used a 2 hour rated system for DGP risers.

If the installation is required to have Pathway 2 or 3 survivability, then the power from an engine driven generator has to have the same survivability. That's per NFPA 72, viz.:

10.5.10.3.1.3 Where survivability of circuits is required by an-
other section of the Code, equal protection shall be provided
for power supply circuits.

Interestingly, this seems not to apply if you don't have a backup generator.

 

[cppoly]

This question was recently answered in minutes committee meeting.

NYC electrical code 700.9(D) requires 1 hour rating for feeder circuits but NFPA 72 requires 2 hour rating based on chapters 23 and 24 so the more stringent applies. 2014 NEC now clarifies this and says 2 hours.

Here's from the minutes:

700.9(D) Fire Protection: Emergency systems shall meet the additional requirements in 700.9(D)(1) and (D)(2) in assembly occupancies for not less than 1000 persons or in buildings above 23 m (75 ft) in height with any of the following occupancy classes: assembly, educational, residential, detention and correctional, business, and mercantile.

(1) Feeder-Circuit Wiring. Feeder-circuit wiring shall meet one of the following conditions:

(1) Be installed in spaces or areas that are fully protected by an approved automatic fire suppression system

(2) Be a listed electrical circuit protective system with a minimum 1-hour fire rating FPN: UL guide information for electrical circuit protection systems (FHIT) contains information on proper installation requirements to maintain the fire rating.

(3) Be protected by a listed thermal barrier system for electrical system components

(4) Be protected by a listed fire-rated assembly that has a minimum fire rating of 1-hour and contains only emergency wiring circuits.

(5) Be embedded in not less than 50 mm (2 in.) of concrete

(6) Be a cable listed to maintain circuit integrity for not less than 1 hour when installed in accordance with the listing requirements

ANSWER 1:

Section 700.9 does not require a 2 hour rating but it requires full sprinkler protection, 1 hour rating, concrete encasement, or a few other options. NFPA 72 requires the 2 hour based on Chapters 23 and 24, and where the two conflict the more stringent must be applied (i.e. the 2 hour). Section 10.5.10.3.1.3 of NFPA 72/2010 also indicates that whatever protection is provided to the low voltage needs to be applied to the power. All of it adds up to needing 2 hour data and 2 hour power.

 

[cppoly]

Forgot to add the original question posted to the committee:

Query 1:
What NYC code provision requires that the power riser for fire alarm equipment throughout a building
with distributed equipment (such as TTB's, remote nodes, amplifiers etc. that all have back up batteries
accompanying them) be a two hour rated power riser providing AC power to them?

Proposed Answer 1:
AC Power riser shall be protected. The 2011 NYC Electrical Code, section 700.9 (D) requires that
electrical circuits for emergency systems to be protected with a minimum 2-hour fire rating for buildings
that are 75 feet or higher in height.