Unformatted text preview: the prime mover on failure of the normal service
shall be provided. For hospitals, the transition-time from instant of failure of the normal
power source to the emergency generator source shall not exceed ten seconds. (See
Section 12.4). 12.9 There shall be two services, each in accordance with Section 200 of the PEC, widely
separated electrically and physically to minimize the possibility of simultaneous
interruption of power supply arising from an occurrence within the building or group of
buildings served. 12.10 Connections on the line side of the main service shall be sufficiently separated from said
main service to prevent simultaneous interruption of supply through an occurrence within
the building or group of buildings served.
12.11 The requirements of Section 12.5 and Section 12.6 also apply to installations where the
entire electrical load on a service or sub-service is arranged to be supplied from a second
source. Current supply from a standby power plant shall satisfy the requirements of
availability in Section 12.6. 12.12 Audible and visual sign devices shall be provided, where practicable, for the following
a) To give warning of dearrangement of the emergency or auxiliary source.
b) To indicate that the battery or generator set is carrying a load.
c) To indicate when a battery charges is properly functioning.
12.13 Only appliances and lamps specified as required for emergency use shall be supplied by
emergency lighting circuits.
12.14 Emergency illumination shall be provided for all required exit lights and all other lights
specified as necessary for sufficient illumination.
Emergency lighting systems should be so designed and installed that the failure of any
individual lighting element, such as the burning out of a light bulb, shall not leave any
area in total darkness.
12.15 Branch circuits intended to supply emergency lighting shall be so installed as to provide
service immediately when the normal supply for lighting is interrupted. Such
installations shall provide either one of the following:
a) An emergency lighting supply, independent of the general lighting system with
provisions for automatically transferring to the emergency lights by means of
devices approved for the purpose upon the event of failure of the general lighting
system supply. b) Two or more separate and complete systems with independent power supply, each
system providing sufficient current for emergency lighting purposes. Unless both
systems are used for regular lighting purposes and are both lighted, means shall be
provided for automatically energizing either system upon failure of the other.
Either or both systems may be part of the general lighting system of the protected
occupancy if circuits supplying lights for emergency illumination are installed in
accordance with other Sections of this Rule. 12.16 For branch circuits which supply equipment classed as emergency, there shall be an
emergency supply source to which the load will be transferred automa...
View Full Document
- Fall '12
- Building code, Building officials