UL 875:2021 PDF Download

The UL 875:2021 standard provides requirements for electric dry-bath heating equipment and other equipment rated 600 volts or less. These devices are designed to create a dry-heat environment with a relative humidity of 10-25 percent, intended to promote perspiration in a short time by means of a warm and dry atmosphere. The equipment must comply with the installation requirements outlined in the National Electrical Code.

The standard covers different types of electric dry-bath heating equipment. This includes heater units intended for fixed installation in a special room, combinations of a heater unit and a prefabricated rigid room, and combinations of a heater and a rigid cabinet. The completed equipment must be equipped with an automatic temperature-regulating control, integral manual-reset limit control, timer, and any other necessary associated equipment.

Steam-bath heaters, cable-type radiant-heating equipment, and other electric heating equipment or appliances that have separate requirements are not covered by this standard. The term "heater" is broadly used throughout the standard to refer to any heater unit and its associated control assembly.

The standard emphasizes the use of appropriate materials, components, and workmanship in the construction of the heater. It also highlights the importance of evaluating products that contain new or different features, characteristics, components, materials, or systems to ensure they maintain the level of safety originally anticipated by the standard. Any conflicts with the specific requirements or provisions of the standard would render the product non-compliant.