This part of IEC 60669 applies to HBES switches with a working voltage not exceeding 250 V a.c. and a rated current up to and including 16 A for household and similar fixed electrical installations either indoors or outdoors and to associated electronic extension units. It applies to: – HBES switches for the operation of lamp circuits and the control of the brightness of lamps (dimmers) as well as the control of the speed of motors (e.g. those used in ventilating fans) and for other purposes (e.g. heating installations); – sensors, actuators, switched-socket-outlets, associated electronic extension units, etc. In the present standard the word "HBES switch" is applied to describe all kinds of HBES devices e.g. switches, sensors, actuators, switched-socket-outlets, associated electronic extension units, etc. The operation and control are performed: – intentionally by a person via an actuating member, a key, a card, etc., via a sensing surface or a sensing unit, by means of touch, proximity, turn, optical, acoustic, thermal; – by physical means, e.g. light, temperature, humidity, time, wind velocity, presence of people; – by any other influence; and transmitted: – by an electronic signal via several media, e.g. powerline (mains), twisted pair, optical fibre, radio frequency, infra-red, etc. HBES switches complying with this standard are suitable for use at ambient temperatures not normally exceeding 25 °C, but occasionally reaching 35 °C. This part of IEC 60669 also applies to mounting boxes for HBES switches, with the exception of those for flush-type HBES switches which are covered by IEC 60670-1. NOTE 1 In the following country flush mounted boxes are covered by both EN 60670-1 and BS 4662: UK Functional safety aspects of HBES switches are not covered by this standard. Functional safety requirements are covered by the standards of the devices which are controlled by the HBES. In locations where special conditions prevail, e.g. higher temperature, special constructions may be required. NOTE 2 This standard is not intended to cover devices falling within the scope of IEC 60730 NOTE 3 Within this Part 2-5, for any reference to IEC 60669-2-1 and its Amendment 1:2008, the term “electronic switches” is replaced by “HBES switches”. NOTE 4 In the following country, HBES switches complying with this standard are suitable for use at ambient temperatures not normally exceeding 35 °C, but occasionally reaching 40 °C: CN.