UL 508 - The UL Safety Standard for Industrial Control Equipment

Industrial Control Equipment is a term commonly used to represent discrete components ranging from selector switches, relays, contactors, motor starters, timers, pilot lights, to complex system of these components. It encompasses more than 30 different product categories and 100 different devices (See Figure1).

 

Figure 1: Examples of industrial control devices covered by UL 508
Industrial Control Devices	Examples
Motor starters and controllers	Including manual, magnetic, and solid-state starters and controllers
Overload relays	Including thermal, magnetic, and solid-state overload relays
Control circuit switches and relays	Including pushbutton stations, selector switches, time-delay relays and pilot lights
Switches	Including float, flow, pressure, vacuum-operated, mercury-tube and proximity switches
Autotransformers, resistors and rheostats	Variable voltage and motor starting
Programmable controllers	Including numerical control systems and industrial microprocessor/computer systems

 

Industrial Control Equipment is used extensively in industrial applications including starting, stopping, regulating, controlling, reversing, changing speed, or protecting electric motors. Components for motor control are installed primarily in control panels, motor control centers, industrial machines as well as energy distribution assemblies. Industrial Control Equipment is required to be designed, built and evaluated for their function and safety in compliance with an established National / International standard. UL 508, covers the safety requirements for Industrial Control Equipment.