UL 508-2021 pdf free download.Industrial Control Equipment.
1.4 Industrial control panels are covered by the requirements in the Standard for Industrial Control Panels, UL 508A.
1.5 Fire pump controllers are covered by the requirements in the Standard for Fire Pump Controllers. UL 218.
1.6 An adjustable-speed drive and accessories or modules for use with an adjustable-speed drive are covered by the Standard for Adjustable Speed Electrical Power Drive Systems — Part 5-1: Safety Requirements — Electrical, Thermal, and Energy, UL 61800-5-1.
1.7 Equipment intended for use in hazardous locations as defined by the National Electrical Code, NFPA 70, are covered by the Standard for Explosion-Proof and Dust-Ignition-Proof Electrical Equipment for Use in Hazardous (Classified) Locations, UL 1203.
1.8 Devices that regulate temperature and/or control refrigeration equipment are covered by the Standard for Temperature-Indicating and -Regulating Equipment, UL 873, and other applicable standards.
Compliance with the Standard for Automatic Electrical Controls for Household and Similar Use, Part 1:General Requirements, UL 60730-1, and/or the applicable Part 2 standard from the UL 60730 series fulfills
these requirements.
1.9 Electrical instruments are covered by the Standard for Electrical Analog Instruments— Panel Board Types, UL 1437.
1.10 Products consisting of interlocked controllers and similar assemblies, intended to transfer power to a common load or output between multiple inputs or sources, are covered by the Standard for Transfer Switch Equipment, UL 1008.
1.11 Magnetic motor controllers, manual motor controllers, combination motor controllers, and overload relays are covered by the Standard for Safety for Low-Voltage Switchgear and Controlgear — Part 4-1:
Contactors and Motor-Starters — Electromechanical Contactors and Motor-Starters, UL 60947-4-1.
2 Glossary
2.1 For the purpose of this standard, the following definitions apply.
2.2 AMBIENT TEMPERATURE — The temperature of the air medium into which the heat of the equipment is dissipated. See 45.12.
2.3 AMBIENT TEMPERATURE RATING — A rating assigned to equipment that refers to the maximum ambient temperature of the room or space outside of the device enclosure or intended enclosure. See 45.13.
2.4 CLOSED-OPEN OPERATION — An operation of closing the test device on the circuit. The letters “CO signify this operation.UL 508 pdf download.