About this chapter: Electrical systems and components are integral to most structures; therefore it is necessary for the code to address their installation and protection. Structures depend on electricity for the operation of many life safety systems including fire alarm, smoke control and exhaust, fire suppression, fire command and communication systems. Since power supply to these systems is essential, Chapter 27 addresses where standby and emergency power must be provided.
The provisions of this chapter and NFPA 70 shall govern the design, construction, erection and installation of the electrical components, appliances, equipment and systems used in buildings and structures covered by this code. The International Fire Code, the International Property Maintenance Code and NFPA 70 shall govern the use and maintenance of electrical components, appliances, equipment and systems. The International Existing Building Code and NFPA 70 shall govern the alteration, repair, relocation, replacement and addition of electrical components, appliances, or equipment and systems.
- Battery charger: Units shall contain a charger capable of charging the battery at a high rate and also at a trickle rate. The high rate charge shall be capable of replacing the maximum charge taken out in a 90-minute discharge period within 12 hours. The unit shall be designed to provide for automatic high rate charging and restoration to trickle rate or shall be provided with a manually operated two- position switch to control the charging rate. After power failure or when the battery becomes discharged so that the unit cannot provide 90-minute illumination at the required intensity, the battery shall be charged at a high rate until it becomes fully charged at which time the charging rate shall be reduced to the trickle rate. No device that could render the charger ineffective shall be permitted.
- Test switch: Units shall be equipped with a test switch mounted outside of the cabinet and connected to simulate a power failure to the unit.
- Signals: Units shall be equipped with a visual signal to indicate when the battery is being charged at the high rate.
- Wiring and mounting: Units and lamps connected remote from the units shall be permanently mounted and connected in an approved manner. Units shall be mounted so that they can be readily tested, inspected, and serviced and shall be maintained in satisfactory working condition. No switch shall be used to cut off the remote lamps.
- Testing: Unit storage battery systems shall be tested at least monthly and a record of such tests shall be maintained and made available for inspection by the code official.
Required critical circuits shall be protected using one of the following methods:
- Cables, used for survivability of required critical circuits, that are listed in accordance with UL 2196 and have a fire-resistance rating of not less than 1 hour.
- Electrical circuit protective systems having a fire-resistance rating of not less than 1 hour. Electrical circuit protective systems are installed in accordance with their listing requirements.
- Construction having a fire-resistance rating of not less than 1 hour.