UL 875 PDF

These requirements cover electric dry-bath heating equipment and other equipment rated 600 volts or less that is intended to produce a dry-heat environment to be installed in accordance with the National Electrical Code, ANSI/NFPA 70. The relative humidity in the heated environment is in the region of 10 – 25 percent and the purpose of the heated environment (for air temperatures, see Sections 25 and 26) is to promote perspiration in a short time by means of a relatively warm and dry atmosphere. The completed equipment is to be provided with an automatic temperature-regulating control that may be integral with the heater or wall-mounted, with an integral manual-reset limit control, a timer, and any other necessary associated equipment. Electric dry-bath heating equipment and other equipment intended to produce a dry-heat environment may consist of:

a) A heater unit intended for fixed installation in a special room that is built or assembled in the field to comply to the manufacturer's size specifications;

b) A combination of a heater unit and a prefabricated, factory-built rigid room in which the assembled combination may be specified for field installation, or that may be supplied with a power-supply cord and intended to be fastened in place or located in a dedicated space. The room may be arranged so that it can be taken apart for shipment; or

c) A combination of a heater and a rigid cabinet that is constructed to enclose all but the user's head. The unit is provided with a power supply cord and is intended to be fastened in place or located in a dedicated space.

These requirements do not cover steam-bath heaters, or cable-type radiant-heating equipment, nor any other electric heating equipment or appliances that are covered in separate, individual requirements.

Throughout these requirements, the term "heater" is used broadly to refer to any heater unit, including its associated control assembly.

A heater shall employ materials and components throughout that are intended for the particular use and shall be made and finished with the degree of uniformity and grade of workmanship practicable in a well-equipped factory.

A product that contains features, characteristics, components, materials, or systems new or different from those covered by the requirements in this standard, and that involves a risk of fire or of electric shock or injury to persons shall be evaluated using appropriate additional component and end-product requirements to maintain the level of safety as originally anticipated by the intent of this standard. A product whose features, characteristics, components, materials, or systems conflict with specific requirements or provisions of this standard does not comply with this standard. Revision of requirements shall be proposed and adopted in conformance with the methods employed for development, revision, and implementation of this standard.