Life Safety 101- Section 7.9.2.3

alixenos

alixenos

Member
Location
Florida
Occupation
Electrical Design Engineer
Hello,

In section 9.1.2 of the life safety code (Electrical Systems) there is a mention to section 7.9.2.3 for emergency lighting. Anyone one familiar with this section? I don't quite understand 7.9.2.3(2) and how to incorporate it into the design.

Here is the section
7.9.2.3 The emergency lighting system shall be arranged to provide
the required illumination automatically in the event of any interruption
of normal lighting due to any of the following:
(1) Failure of a public utility or other outside electrical power
supply
(2) Opening of a circuit breaker or fuse
(3) Manual act(s), including accidental opening of a switch controlling
normal lighting facilities.

If I'm providing one circuit to a space coming from an emergency panel, is that not enough?

Thanks.
 
Emergency exit signs and the bug eye looking lights sometimes have their own battery packs in the assembly.
 
BillyMac59 said:
This usually means a battery backup. The main emergency lighting circuit can be run thru a backup generator with an A
Click to expand...
All my light fixtures don't have a battery backup. Does that mean I need to provide two circuits from two different panels?
 
alixenos said:
All my light fixtures don't have a battery backup. Does that mean I need to provide two circuits from two different panels?
Click to expand...
You only need enough lighting to meet whatever is required for emergency illumination and exit.
 
101 is not typically an adopted code. Egress and exit lighting / signage requirements are found in the adopted building code. If it were the IBC, 1008 covers egress and 1013 covers exit signage.

CHAPTER 10 MEANS OF EGRESS - 2024 INTERNATIONAL BUILDING CODE (IBC)

ICC Digital Codes is the largest provider of model codes, custom codes and standards used worldwide to construct safe, sustainable, affordable and resilient structures.
codes.iccsafe.org codes.iccsafe.org
 
Understand that the purpose emergency lighting is to illuminate an area for a period of time (30 minutes?) to allow personnel to safely evacuate the area. It is not meant to be a backup lighting system. Adding multiple supply circuits does nothing if all electrical power is lost. A second power source - ie a generator - might be your best option. Of course, this means proper ignition of the generator and switching into existing circuitry.
 
BillyMac59 said:
Understand that the purpose emergency lighting is to illuminate an area for a period of time (30 minutes?) to allow personnel to safely evacuate the area. It is not meant to be a backup lighting system. Adding multiple supply circuits does nothing if all electrical power is lost. A second power source - ie a generator - might be your best option. Of course, this means proper ignition of the generator and switching into existing circuitry.
Click to expand...
I am supplying the lighting circuits from an emergency panel. The above code I think discusses the possibility of opening of a circuit breaker that will cause the lighting to lose power ( normal source and/or generator still exit).
If Im understanding it correctly, I need to supply the lighting from two different emergency panels, if one breaker trips the other wont.
 
alixenos said:
I am supplying the lighting circuits from an emergency panel. The above code I think discusses the possibility of opening of a circuit breaker that will cause the lighting to lose power ( normal source and/or generator still exit).
If Im understanding it correctly, I need to supply the lighting from two different emergency panels, if one breaker trips the other wont.
Click to expand...
Depends on what the emergency Panel is fed from. If it is from a valid NEC Article 700 source, then one circuit is ok, and must be kept physically separated from non-emergency circuits.
 
Yes its fed from a panel compliant with NEC 700.
If that panel MCB or branch circuit breaker trips, then the illumination will lose both sources of energy ( Normal and Generator)
How can such possibility be addressed if we provide one circuit only?
 
alixenos said:
Yes its fed from a panel compliant with NEC 700.
If that panel MCB or branch circuit breaker trips, then the illumination will lose both sources of energy ( Normal and Generator)
How can such possibility be addressed if we provide one circuit only?
Click to expand...
It is code compliant to have a single circuit (that doesn't mean you couldn't do more if you want).

Due to the risk, that is why the code requires selective coordination for OCPDs and physically separated circuitry for Article 700 circuits.
 
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