This clause of Part 2-1 is replaced by the following:This collateral standard 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 ), - to sensors, actuators, switched-socket-outlets, associated electronic extension units, etcIn the following document the word " HBES switch " is applied to describe all kind 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. Functional safety aspects of HBES switches are not covered by this standard. Functional safety requirements shall be 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.