AS NZS IEC 60947.5.6:2015 pdf free download – Low-voltage switchgear and controlgear
1 Scope
This International Standard applies to proximity sensors connected for operation by a two-wire connecting cable to the control input of a switching amplifier. The switching amplifier contains a d.c. source to supply the control circuit and is controlled by the variable internal resistance of the proximity sensor. These devices can be used in an explosive atmosphere if they also comply with IEC 60079-11.
NOTE These devices have been defined by the German organization ‘ NormenausschuB fur MeB- und Regelungstechnik (NAMUR)” (Office for Standardization of Measurement and Regulation Techniques).
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references， subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. F or undated references, the latest edition of the normative document referred to applies. Members of IEC and ISO maintain registers of currently valid International Standards.
IEC 60079-11:1999, Electrical apparatus for explosive gas atmospheres – Part 11: Intrinsic safety“i”
IEC 60947-1:1999, Low-voltage switchgear and controlgear – Part 1: General rules
IEC 60947-5-2:1999, Low-voltage switchgear and controlgear – Part 5-2: Control circuit devices and switching elements – Proximity switches
3.3 control circuit
system comprising the proximity sensor, the control input of the switching amplifier and the two-wire connecting cable
3.4 output signal of the proximity sensor
output current as a function of the variable internal resistance
3.5 distance/current characteristic of the proximity sensor
relationship of the output signal (the current value) in the steady state to the distance of the influencing body relative to the sensor. Both continuous and discontinuous characteristics are permitted (see 5.3 and 5.4, and figures 1 and 2)
3.6 actuating range
range defined by four straight lines in the current-voltage graph of the control input of the switching amplifier to which is assigned a switching function of the switching amplifier. There are three actuating ranges covered by the current-voltage characteristic of the control input (see figure 3, a, b and d)
3.8 maximum-operating frequency of the proximity sensor
maximum switching frequency achieved through periodic influencing at which the limits of the actuating range (OH) are reached (see figures 1 and 2)
3.9 switching current difference
change in control current within the actuating range (OH) at which the switching amplifier changes its output signal (see figures 1, 2 and 3)
3.10 switching travel difference
travel of the influencing body which changes the output signal of the switching amplifier. With a discontinuous characteristic of the proximity sensor, the switching travel difference is identical to the control span As
3.11 line resistance
effective resistance of the two-wire connecting cable between the switching amplifier and the proximity sensor