IEC TS 62996
Industrial electroheating and electromagnetic processing equipment – Requirements on touch currents, voltages and electric fields from 1 kHz to 6 MHz
|Publication Date:||1 September 2017|
|ICS Code (Electric furnaces):||25.180.10|
This document addresses the safety assessments in the frequency range between 1 kHz and 6 MHz and provides limits for touch and touch currents for industrial installations or equipment for electroheating (EH) and electromagnetic processing of materials (EPM). Indirect contact by capacitive currents to parts of an earthed human body in an open space are also included, since the current is then distributed analogously in the part of the body and differs from cases of induced electric shock.
NOTE 1 Induced electric shock phenomena are caused by the alternating magnetic field external to a current-carrying conductor, inducing an electric field in a part of the body in the vicinity of or directly contacting it. The causes are thus different from those causing electric shock phenomena and are dealt with in IEC TS 62997 on magnetic nearfield safety, developed by TC 27.
The overall safety requirements for the various types of EH or EPM equipment and installations in general result from the joint application of the general requirements specified in IEC 60519-1:2015 and related particular requirements covering specific types of installations or equipment. This document complements IEC 60519-1:2015.
NOTE 2 This document complements Annex B in IEC 60519-1:2015.
On contacting, this document is based primarily on a movement of the primary contact area in relation to the live part, resulting in a contact or touch current. The awareness, perception and reaction times differ in comparison with a situation where a person is, for example, leaning towards or holding a conductor which subsequently becomes live, or a similar fault condition. Different considerations are then applicable and are dealt with in a detailed way in this document.
Since high impedances for dry skin will result in the lowest touch current and the dryness is typically variable, data for only moist and wet skin are used in this document.