UL 60730-2-101 Ed. 1-2022

Outline of Investigation for Automatic Electrical Controls - Part 2-101: Particular Requirements for Electrical Sensors and Sensing Elements - Published Date: April 10, 2020

This part of UL 60730 applies to the safety of electrical, electro-mechanical and electronic sensors including sensing elements and any conditioning circuitry. Discrete sensors covered under the scope of this document serve only to transform an activating quantity into a usable output and do not perform a control operation as defined in the part 1.  Discrete sensors, as defined herein, are used within controls or as independent devices used in connection with controls and control systems.  This document applies to discrete sensors constructed of, but not limited to, conductor, semi-conductor substrate and Micro-Electromechanical Systems (MEMS), for the detection of activating quantities such as temperature, pressure, humidity, light (e.g. optical), gasoline vapours, and the like.  Note: Future consideration will be given to other sensors technologies constructed of other materials such as, chemical, mechanical elements along with other activating quantities like mass flow, liquid, movement, weight, vibration, or other as needed.  This document is applicable to discrete sensing elements in so far as defining the safety of its inherent operating characteristics and corresponding response.  This document applies to any electronic hardware, software, or other conditioning circuits that are inherent to the sensor and relied upon to reliably transform the input signal into a useable response signal (output) for functional safety purposes.  Note 1: Additional requirements may be also applied by the application standard in which the sensor is used.  Note 2: Conditioning circuits that are inseparable from the control for which the sensing element relies upon to perform its desired function are evaluated by the requirements of the relevant control standard and/or the Part 1, IEC 60730-1. The sensing element itself may be evaluated to this document.  Throughout this document, whenever it is indicated that the Part 1 requirements are applicable, the term “control(s)”, is replaced by the term “sensor(s)”, and the term “equipment” is replaced by the term “control”, as they are used in the Part 1, respectively, unless otherwise specified herein.  This document does not apply to sensors explicitly described in another relevant part 2 of the UL 60730 series.  Note 2: For example, a flame sensor as described in 60730-2-5.  This document does not apply to flame supervision devices and thermocouples that are already described in ISO 23551-6 and ISO 23551-8, respectively.  This document does not apply to sensors used for laboratory measurement equipment covered under standard UL 61010, Safety requirements for electrical equipment for measurement, control, and laboratory use – Part 1: General requirements.