operate during a fire in or under the hood.
(6) Supply, return, and exhaust ventilating systems for airborne infectious/isolation rooms, protective environment rooms, exhaust fans for laboratory fume hoods, nuclear medicine areas where radioactive material is used, ethylene oxide evacuation, and anesthesia evacuation. Where delayed automatic connection is not appropriate, such ventilation systems shall be permitted to be placed on the critical branch. [99:4.4.2.2.3.4(1) through (6)]
(7) Supply, return, and exhaust ventilating systems for operating and delivery rooms.
Exception: Sequential delayed automatic connection to the alternate power source to prevent overloading the generator shall be permitted where engineering studies indicate it is necessary.
(B) Equipment for Delayed Automatic or Manual Connection. The following equipment shall be permitted to be arranged for either delayed automatic or manual connection to the alternate power source:
(1) Heating equipment to provide heating for operating, delivery, labor, recovery, intensive care, coronary care, nurseries, infection/isolation
rooms, emergency treatment spaces, and general
patient rooms and pressure maintenance (jockey
or make-up) pump(s) for water-based fire
protection systems.
Exception: Heating of general patient rooms and infection/isolation rooms during disruption of the normal source shall not be required under any of the following conditions:
(1) The outside design temperature is higher than -6.7°C (20°F).
(2) The outside design temperature is lower than
-6.7°C (20°F), and where a selected room(s) is
provided for the needs of all confined patients, only
such room(s) need be heated.
(3) The facility is served by a dual source of normal power.
FPN No. 1: The design temperature is based on the
97 Vi percent design value as shown in Chapter
24 of the ASHRAE Handbook of Fundamentals
(1997).
FPN No. 2: For a description of a dual source of normal power, see 517.35(C), FPN.
(2) An elevator(s) selected to provide service to patient, surgical, obstetrical, and ground floors during interruption of normal power. In instances where interruption of normal power would result in other elevators stop ping between floors, throw-over facilities shall be pro vided to allow the temporary operation of any elevator for the release of patients or other persons who may be confined between floors.
(3) Hyperbaric facilities.
(4) Hypobaric facilities.
(5) Automatically operated doors
(6) Minimal electrically heated autoclaving equipment shall be permitted to be arranged for either automatic or manual connection to the alternate source.
(7) Controls for equipment listed in 517.34.
(8) Other selected equipment shall be permitted to be served by the equipment system. [99:4.4.2.2.3.5(9)]
(C) AC Equipment for Nondelayed Automatic Connection. Generator accessories, including but not limited to, the transfer fuel pump, electrically operated louvers, and other generator accessories essential for generator operation, shall be arranged for automatic connection to the alternate power source. [99:4.4.2.2.3.3]
517.35 Sources of Power.
(A) Two Independent Sources of Power. Essential electrical systems shall have a minimum of two independent sources of power: a normal source generally supplying the entire electrical system and one or more alternate sources for use when the normal source is interrupted. [99:4.4.1.1.4]
(B) Alternate Source of Power. The alternate source of power shall be one of the following:
(1) Generator(s)