IEC 60947-8-2021 pdf download.Low-voltage switchgear and controlgear – Part 8: Control units for built-in thermal protection (PTC) for rotating electrical machines.
This part of IEC 60947 series specifies requirements for control units, which control a switching device in response to the PTC thermistors incorporated in rotating electrical machines and the industrial application.
It specifies requirements for that type of system comprising a positive temperature coefficient (PTC) thermistor having particular characteristics, and its associated control unit.
This document includes:
– the characteristics, construction, performance and tests of the control unit; and
– its association with a PTC thermistor designated “Mark A”.
This document does not cover:
– the incorporation of thermal protections into rotating machines and their maximum winding temperature. See IEC 60034-1 1 ;
– use of the product within explosive atmospheres (see IEC 60079 (all parts));
– software and firmware requirements;
NOTE 1 Guidance on embedded software is given in IEC TR 63201 .
– cyber security aspects (see IEC TS 63208).
NOTE 2 It is not possible to specify all the requirements for the operating characteristics of a control unit, as they are dependent on some aspects of the PTC thermistors. Some aspects of the requirements of the thermal protector system can only be specified when account is taken of the characteristics of the rotating machine to be protected and the method of installation of the PTC thermistor within the machine.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any amendments) applies.
CISPR 1 1 :201 5, Industrial, scientific and medical equipment – Radio-frequency disturbance characteristics – Limits and methods of measurement CISPR 1 1 :201 5/AMD1 :201 6
IEC 60068-2-6:2007, Environmental testing – Part 2-6: Tests – Test Fc: Vibration (sinusoidal)
IEC 60068-2-27:2008, Environmental testing – Part 2-27: Tests – Test Ea and guidance: Shock
IEC 6041 7, Graphical symbols for use on equipment (available at http://www.graphical- symbols.info/equipment)
IEC 60445, Basic and safety principles for man-machine interface, marking and identification – Identification of equipment terminals, conductor terminations and conductors
IEC 60730-1 , Automatic electrical controls – Part 1: General requirements
IEC 60738-1 :2006, Thermistors – Directly heated positive temperature coefficient – Part 1:
Generic specification
IEC 60738-1 :2006/AMD1 :2009
IEC 60738-1 -4:2008, Thermistors – Directly heated positive step-function temperature coefficient – Part 1-4: Blank detail specification – Sensing application – Assessment level EZ
IEC 60947-1 :2020, Low-voltage switchgear and controlgear – Part 1: General rules
IEC 60947-5-1 :201 6, Low-voltage switchgear and controlgear – Part 5-1: Control circuit devices and switching elements – Electromechanical control circuit devices
IEC 61 1 40:201 6, Protection against electric shock – Common aspects for installation and equipment
ISO 2859-1 :1 999, Sampling procedures for inspection by attributes – Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection
ISO 2859-1 :1 999/AMD1 :201 1
3 Terms and definitions, symbols and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60947-1 :2020, as well as the following terms and definitions, apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1.1 built-in thermal protection
protection of certain parts (called protected parts) of a rotating electrical machine against excessive temperatures resulting from certain conditions of thermal overload, achieved by means of a thermal protection system, the whole or part of which is a thermally sensitive device incorporated within the machine.IEC 60947-8 pdf download.