UL 917

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These requirements cover clock-op erated switches rated 600 V or less, to be used in ordinary locations designed to close and open circuits to a load at predetermined intervals, and intended to be employed i n accordance with the National Electrical Code, ANSI/NFPA 70.

These requirements cover only clock-operated switches in which the switching contacts are actuated by a clock-work, by a gear-train, by hand, by electrically-wound spring motors, by electric clock-type motors, or by equivalent arrangements. In addition to closing and opening the switching contacts, the devices may also indicate the time of day or time interval.

These requirements do not cover devices incorporating electronic timing circuits or switching circuit s without separable contacts.

A clock-operated switch, which is incomplete in construction features or restricted in performanc e capabilities, is acceptable for us e as a factory-installed component provided that the restrictions established for the component are eliminated when the component is installed.

Specific provisions are included in these requirements for TV rated clock-operated switches.

A product that contains features, characteristics, components, materials, or systems new or different from those in use when the Standard was developed, and that involves a risk of fire, electric shock, or injury to persons, shall be evaluated using the appropriate additional component and end-product requirements as determined necessary to mai ntain the level of safety for the user of the product as originally anticipated by the intent of this Standard.