IEC 60519-8:2020 pdf download

IEC 60519-8:2020 pdf download.Safety in installations for electroheating and electromagnetic processing
1 Scope
This clause of Part 1 is modified as follows. Modification: This part of IEC 60519 specifies particular safety requirements for electroslag remelting equipment and installations. This document specifies safety requirements applicable to mainly electroheating installations for remelting and, in some cases, for refining processes of metals through direct resistance heating of a conductive slag. The object of this document is to specify the particular requirements for the safety of persons in or around an electroslag remelting furnace. The general requirements are included in IEC 60519-1.
2 Normative references
This clause of Part 1 is applicable except as follows. Addition: IEC 60519-1, Safety in installations for electroheating and electromagnetic processing – Part 1: General requirements
3 Terms and definitions
This clause of Part 1 is applicable except as follows. 3.2 Equipment and state of equipment Addition: 3.2.101 electroslag remelting furnace remelting furnace in which the charge, usually a consumable electrode, is remelted by direct resistance heating of an electrical conductive molten slag Note 1 to entry: The slag is contained in a mould (crucible).
7 Protection against hazards from electric shock
This clause of Part 1 is applicable except as follows. 7.6 Protective equipotential bonding Addition: 7.6.101 The following requirements apply to the power circuit. 1) This circuit shall include an earthing connection preferably at the base plate, which supports the ingot. If the installation enables several melting stations to be supplied from the same power supply, each station shall be provided with an earth connection. For the particular case of a single-head multi-station co-axial electroslag remelting furnace, it is preferable to ground the power circuit at the power supply instead of at the base. In no case shall the operating personnel be exposed to harmful voltages.If the power circuit is multiple-earthed, care shall be taken with the current which flows between the earthing points and through components of the furnace. 2) The circuit of any melting station which is not working shall be isolated from the supply but not from earth.
10 Protection against hazards from thermal influences
This clause of Part 1 is applicable, except as follows. 10.1 General Additions: 10.1.101 Perforation of the crucible and base plate can cause a fire or an explosion due to the cooling-water flow into liquid metal and slag. The following special measures for design and operation of equipment shall be taken to ensure the protection of personnel and equipment. a) Sufficient water-cooling to the crucible and base plate shall be ensured in the hot state. For further details, see 10.5. b) The size of electrode(s) relative to the crucible shall be carefully designed and manufactured in such a way that they remain at a reasonable distance between the crucible and the electrode(s) to avoid the occurrence of arcing. The position of electrode(s) relative to the crucible shall be monitored during melting and aligned. c) The mechanical properties of graphite electrode(s) and consumable electrode(s) shall be ensured to avoid cracking and a part of electrode dropping into the crucible that can cause arcing during the operation. The electrode(s) with horizontal cracks in the surface or inside is (are) unacceptable. d) The strength of the welded zone between the consumable electrode and the electrode stub in the operation condition shall be sufficient to avoid it breaking away. e) The voltage and current in the secondary circuit shall be carefully set and controlled to the limited values in the starting phase, especially in the case of cold starting with solid conductive slag, in order to avoid the electrode arcing or short circuit occurring with the base plate that can cause perforation of the base plate.