system equipment shall be suitable for the maximum available fault current at its terminals.
(B) Selective Load Pickup, Load Shedding, and Peak Load Shaving. The alternate power source shall be permitted to supply emergency, legally required standby, and optional standby system loads where the source has adequate capacity or where automatic selective load pickup and load shedding is provided as needed to ensure adequate power to (1) the emergency circuits, (2) the legally required standby circuits, and (3) the optional standby circuits, in that order of priority. The alternate power source shall be permitted to be used for peak load shaving, provided these conditions are met.
Peak load shaving operation shall be permitted for
satisfying the test requirement of 700.4(B), provided all
other conditions of 700.4 are met.
A portable or temporary alternate source shall be available whenever the emergency generator is out of service for major maintenance or repair.
700.6 Transfer Equipment .
(A) General. Transfer equipment, including automatic transfer switches, shall be automatic, identified for
emergency use, and approved by the authority having jurisdiction. Transfer equipment shall be designed and installed to prevent the inadvertent interconnection of normal and emergency sources of supply in any operation of the transfer equipment. Transfer equipment and electric power production systems installed to permit operation in parallel with the normal source shall meet the requirements of Article 705.
(B) Bypass Isolation Switches. Means shall be permitted to bypass and isolate the transfer equipment. Where bypass isolation switches are used, inadvertent parallel operation shall be avoided.
(C) Automatic Transfer Switches. Automatic transfer switches shall be electrically operated and mechanically held. Automatic transfer switches, rated 600 VAC and below, shall be listed for emergency system use.
(D) Use. Transfer equipment shall supply only emergency loads.
700.7 Signals. Audible and visual signal devices shall be provided, where practicable, for the purpose described in 700.7(A) through (D).
(A) Derangement To indicate derangement of the emergency source.
(B) Carrying Load. To indicate that the battery is carrying load.
(C) Not Functioning. To indicate that the battery charger is not functioning.
(D) Ground Fault. To indicate a ground fault in solidly grounded wye emergency systems of more than 150 volts to ground and circuit-protective devices rated
1000 amperes or more. The sensor for the ground-fault signal devices shall be located at, or ahead of, the main system disconnecting means for the emergency source, and the maximum setting of the signal devices shall be for a ground-fault current of 1200 amperes. Instructions on the course of action to be taken in event of indicated ground fault shall be located at or near the sensor location.
FPN: For signals for generator sets, see NFPA 110-2005, Standard for Emergency and Standby Power Systems.
700.8 Signs.
(A) Emergency Sources. A sign shall be placed at the service-entrance equipment, indicating type and location of on-site emergency power sources.
Exception: A sign shall not be required for individual unit equipment as specified in 700.12(F).