IEC 60974-3-2019 pdf free.Arc welding equipment- Part 3:Arc striking and stabilizing devices.
Stand-alone ARC STRIKING and STABILIZING DEViCEs shall be class l or class ll equipment inaccordance with lEC 61140, with the exception of the welding circuit.
The output circuit of the ARC STRIKING AND STABILIZING DEVICE shall be electrically isolated fromthe public supply system by double or reinforced insulation in accordance with the maximumrated input voltage. Annex A，Figure A.1 shows examples of coupling systems for ARCSTRIKING AND STABILIZING DEVICES.
Internal conductors and connections shall be secured or positioned as specified in 6.3.3 ofIEC 60974-1:2017.
For class l stand-alone ARC STRIKING AND STABILIZING DEVICE，weighted touch current in thecase of an external protective conductor failure or disconnection shall not exceed the valuespecified in 6.3.6 of lEC 60974-1:2017 when energized and not providing the ARC STRIKINGAND STABILIZING VOLTAGE.
Conformity shall be checked by visual inspection and by measurement.
6.4Protective provision
Connection of exposed conductive parts to the protective conductor is not required if the ratedsupply voltage is supplied by the welding circuit or safety extra-low voltage (SELV).
7 Thermal requirements
Current-carrying components，incorporated in the ARC STRIKING AND STABILIZING DEVICE,shallbe capable of carrying the rated welding current as specified by the manufacturer without:
a) exceeding the temperature rating of the current-carrying components;
b) causing the surface temperatures specified in Table 7 of IEC 60974-1:2017 to be exceeded.
For liquid-cooled apparatus，the test shall be carried out with the minimum flow and themaximum temperature of the coolant, as recommended by the manufacturer.
8 Thermal protection
lf the ARC STRIKING and STABILIZING DEVICE is designed for use with or built in a specificwelding power source, the thermal protection tests shall be carried out with the welding powersource.
9Abnormal operation
In the case of a stand-alone ARC STRIKING and STABILIZING DEVICE, the abnormal operationtests defined in Clause 9 of lEC 60974-1:2017 shall be carried out as applicable.
lf the ARC STRIKING and STABILIZING DEVICE is designed for use with a specific welding powersource, the abnormal operation tests shall be conducted with the ARC STRIKING and STABILIZINGDEVICE connected to that welding power source.
The ARC STABILIZING DEVICE shall be short circuited at the output，with neither a torch nor areturn cable connected，until equilibrium is achieved.
ARC STRIKING AND STABILIZING DEVICEs protected internally,for example by automatic shut-off,meet this requirement if the protection device operates before an unsafe condition occurs.
10 Connection to the supply network
Clause 10 of lEC 60974-1:2017 applies.
11 Output
11.1 Rated peak voltage
The rated peak voltage (u ) is obtained by subtraction of the no-load voltage (U%) from themeasured peak voltage (see Figure 1).To determine the peak, the voltage shall be measuredacross a 220 pF capacitor with neither a torch nor a return cable connected.
When reported on the rating plate of ARC STRIKING AND STABILIZING DEVICES, the rated peakvoltage (U,) shall be equal to or greater than the measured peak voltage, but shall not exceedthe maximum values given in Table 2.IEC 60974-3 pdf download.