BS EN IEC 60519-8-2020 pdf download.Safety in installations for electroheating and electromagnetic processing – Part 8: Particular requirements for electroslag remelting furnaces (IEC 60519-8:2020).
4 Classification and sub-division of equipment and installations
This clause of Part 1 is applicable except as follows.
4.1 Classification by processing frequency
Addition:
The voltage band is determined by the line-to-line open-circuit rated supply voltage to the
electrode(s).
5 Risk assessment
This clause of Part 1 is applicable.
6 General provisions
This clause of Part 1 is applicable.
7 Protection against hazards from electric shock
This clause of Part 1 is applicable except as follows.
7.6 Protective equipotential bonding
Addition:
7.6.1 01 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.
8 Protection against hazards from electric or magnetic fields
This clause of Part 1 is applicable.
9 Protection against hazards from radiation
This clause of Part 1 is applicable.
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 1 0.5. 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. 10.1 .102 Slag materials shall be sufficiently dried before use in order to decrease the moisture so that molten slag cannot be ejected from the crucible during the melting of the slag. 10.1 .103 The relative positions between the mould and the base plate shall be fixed and the gap between them shall be so narrow that the molten slag cannot leak out. 10.1 .104 Water accumulation in the area around the melting station shall be avoided. Measures shall be taken to remove any water from this area in the event of leakage.BS EN IEC 60519-8 pdf download.