IEC 60974-8-2021 Arc welding equipment – Part 8: Gas consoles for welding and plasma cutting systems.
6 Protection against electric shock
6.1 Insulation
6.1.1 General
As specified in 6.1 .1 of IEC 60974-1 :201 7, with the following exception:
The micro-environment of printed circuit boards shall be improved to pollution degree 2 or better (by means such as filtering, coating, potting, moulding) so that only non-conductive pollution or occasional temporary conductivity caused by condensation occurs in accordance with IEC 60664-1 .
6.1.2 Clearances
As specified in 6.1 .2 of IEC 60974-1 :201 7.
6.1.3 Creepage distances
As specified in 6.1 .3 of IEC 60974-1 :201 7.
6.1.4 Insulation resistance
As specified in 6.1 .4 of IEC 60974-1 :201 7.
6.1.5 Dielectric strength
As specified in 6.1 .5 of IEC 60974-1 :201 7.
6.2 Protection against electric shock in normal service (direct contact)
6.2.1 Protection provided by the enclosure
The minimum degree of protection for GAS CONSOLES shall be IP21 S in accordance with IEC 60529.
Conformity shall be checked by:
a) applying the articulated finger and ball, as specified in IEC 60529, to any openings and ensuring it does not contact any hazardous live part; and
b) verifying that immediately after the water test, as specified in IEC 60529, the unit satisfies insulation resistance and the dielectric strength tests and is able to operate.
No power is applied to the unit while performing these tests.
6.2.2 Capacitors
As specified in 6.2.2 of IEC 60974-1 :201 7.
6.2.3 Automatic discharge of supply circuit capacitors
As specified in 6.2.3 of IEC 60974-1 :201 7.
6.2.4 Isolation of the welding circuit
As specified in 6.2.4 of IEC 60974-1 :201 7.
6.2.5 Welding circuit touch current
As specified in 6.2.5 of IEC 60974-1 :201 7.
6.2.6 Touch current in normal condition
As specified in 6.2.6 of IEC 60974-1 :201 7.
6.3 Protection against electric shock in case of a fault condition (indirect contact)
As specified in 6.3 of IEC 60974-1 :201 7.
7 Thermal requirements
7.1 Heating test
As specified in 7.1 of IEC 60974-1 :201 7.
7.2 Temperature measurement
As specified in 7.2 of IEC 60974-1 :201 7.
7.3 Limits of temperature rise
As specified in 7.3 of IEC 60974-1 :201 7.
Additionally, the temperature of surfaces exposed to combustible gases shall be at least 20 % cooler than the ignition temperature of any combustible gas intended to be used in the GAS CONSOLE .
Conformity shall be checked by operating the GAS CONSOLE at the maximum specified ambient temperature and system duty cycle, while monitoring the inside of the gas console with an IR camera for temperatures exceeding the 20 % margin of the ignition temperature of any combustible gas intended to be used in the GAS CONSOLE .
a) with the combinations of gas(es) and flow rates which creates the worst-case condition, as
specified by the manufacturer;
b) with the cooling liquid as specified by the manufacturer.
8 Connections for plasma cutting torches
As specified in 1 1 .4.6 of IEC 60974-1 :201 7, where the torch connects to the GAS CONSOLE .
9 Mechanical provisions
9.1 General
As specified in Clause 1 4 of IEC 60974-1 :201 7, with the following additions.IEC 60974-8 pdf download.