AS NZS IEC 60947.5.8:2015 pdf free download – Low-voltage switchgear and controlgear
5.2.1 General
Marking of data specified in items a), b), c) and d) of 5.1 is mandatory on the nameplate of the three-position enabling switch in order to permit the complete information to be obtained from the manufacturer.
Marking shall be indelible and easily legible, and shall not be placed on screws and easily removable parts.
Whenever space permits, data under items e) to o) of 5.1 shall be included on the nameplate,or on the three-position enabling switch or otherwise in the manufacturer’s published literature.
6 Normal service, mounting and transport conditions
Clause 6 of IEC 60947-1 applies with the following additions.
6.1.3.2 Pollution degree
Unless otherwise stated by the manufacturer, a three-position enabling switch is intended for installation under environmental conditions of pollution degree 3. However, other pollution degrees may apply, depending upon the micro-environment.
6.3 Mounting
Means shall be provided to allow the three-position enabling switch to be securely installed in its intended mounting position.
7.1 Constructional requirements
Subclause 7.1 of IEC 60947-1 applies except for 7.1 .1 , 7.1 .2, 7.1 .6, 7.1 .8 and 7.1 .1 2, and with the following additions.
7.1.1 Materials
Subclause 7.1 .1 of IEC 60947-5-1 applies.
7.1.2 Current-carrying parts and their connections
Subclause 7.1 .2 of IEC 60947-5-1 applies.
7.1.3 Clearances and creepage distances
Subclause 7.1 .3 of IEC 60947-5-1 applies.
7.1 .4.3 Actuating force (or moment)
The force (or moment) required to operate the actuator shall be compatible with the intended application, taking into account the size of the actuator, the type of enclosure or panel, the environment of the installation and the use for which it is intended.
7.1 .7 Class II three-position enabling switches
Subclause 7.1 .7 of IEC 60947-5-1 applies.
7.1 .8 Requirements for three-position enabling switches with integrally connected cables Subclause 7.1 .8 of IEC 60947-5-1 applies.
7.1.9 Three-position operation
The three positions are designated as follows (see Figure 2):
− position 1 : OFF state of the contact (actuator is not pressed);
− position 2: ON state of the contact (actuator is pressed to the normal enabling position);
− position 3: OFF state of the contact (actuator is fully depressed).
The three-position enabling switch pressed to position 2 shall return to position 1 when released. The three-position enabling switch shall change from position 2 to position 3 when pressed further. When released from position 3 to position 1 , the switching element shall not close when the actuator passes through position 2.
Figure 1 illustrates the three positions and the corresponding contact states.
7.1.1 0 Operational characteristics
The three-position enabling switch shall be designed and manufactured to satisfy the following operational characteristics.
• To reduce physiological strain during actuation of three-position enabling switches, F 2 shall be 1 0 N or smaller.
• To reduce the possibility of inadvertent shifting of three-position enabling switches to position 3, F 3 shall be 2 F 2 or greater and F 3 shall be 2 F 1 or greater.
• F 5 shall be 1 50 N or greater (see 8.2.6).