1.1 These requirements cover uninterruptible power supplies (UPS) rated 600 volts or less ac or dc that are intended for installation in accordance with the National Electrical Code, NFPA 70. During normal operation, the UPS allows the primary or normal power source to deliver ac power to the protected load through either the power conversion portion of the UPS or a bypass source. The power conversion portion of the UPS consists of a rectifier, an inverter, or both. During periods of power fluctuations, or power outages, or both, the connected load receives ac power from the battery supply and power conversion portion of the UPS.

1.2 Products that are used with UPS and that are covered by this standard include:

1. a) Remote battery supply cabinets with or without batteries;

2. b) Remote status panels;

3. c) Bypass switches;

4. d) Maintenance bypass switches;

5. e) Rectifier, power conversion units, or both; and

6. f) Power distribution panels.

1.3 A battery supply (see 4) used with a UPS covered by this standard may consist of any of the following described in (a) – (c):

1. a) A battery supply that is integral with the UPS. The batteries may or may not be furnished with the UPS.

2. b) A battery supply that is contained in a remote cabinet. For a cord-and-plug-connected UPS having an ac input rating of 20 amperes or less and 125 volts ac maximum, the battery supply is furnished with the UPS. For all other UPS intended for use with a remote battery and cabinet assembly, the battery supply may or may not be furnished with the UPS.

3. c) A battery supply that is contained in a separate battery room. This type of battery supply may or may not be furnished with the UPS.

1.4 These requirements cover static type UPS– not rotary type UPS.

1.5 This standard does not cover Uninterruptible Power Supplies (UPS) intended for use in health care facilities. UPS intended for use in such facilities shall comply with the requirements of this standard and the Standard for Safety of Medical Electrical Equipment, Part 1: General Requirements, UL 60601-1. UPS that employ hospital grade components identified by the markings "Hospital Only", "Hospital Grade", or a green dot on the body of the component, or otherwise implying suitability for medical use shall be evaluated to these standards.

1.6 These requirements cover UPS equipment that may be installed in accordance with the Standard for Protection of Electronic Computer/Data-Processing Equipment, ANSI/NFPA 75. This equipment is marked indicating that it is suitable for such use. See 27.

1.7 Engine-driven, dc power generators intended to provide backup power for the battery supply circuit of UPS units are investigated for compliance with the requirements in the Standard for Engine-Generator Assemblies for Use in Recreational Vehicles, UL 1248.

1.8 These requirements do not cover UPS units for use as emergency systems nor legally required standby systems described in Articles 700 and 701 respectively of the National Electrical Code, ANSI/NFPA 70.

1.9 Deleted

1.10 Any undated reference to a code or standard appearing in the requirements of this standard shall be interpreted as referring to the latest edition of that code or standard.