IEC 60974-11 pdf free download
IEC 60974-11 pdf free download.Arc welding equipment – Part 11: Electrode holders.
8 Protection against electric shock
8.1 Protection against direct contact
An ELECTRODE HOLDER without an electrode, fitted with a welding supply cable of minimum cross- sectional area as specified by the manufacturer, shall be protected against unintentional contact with live parts.
In the case of CATEGORY A ELECTRODE HOLDERS, this requirement is also valid for the part of the electrode inserted into the ELECTRODE HOLDER. Electrodes having the minimum and maximum diameter as specified by the manufacturer shall be tested.
Conformity shall be checked by:
a) an access probe according to Table 6 of lEO 60529:1989 in the case of ELECTRODE HOLDERS of:
1) CATEGORYA, and
2) CATEGORY B with the exception of the HEAD;
b) a sphere in the case of the HEAD of CATEGORY B ELECTRODE HOLDERS with:
1) a metal sphere of 12,5 mm diameter according to IEC 60529 for electrodes up to 6,3 mm diameter, or
2) a metal sphere of d°’°5 mm diameter for electrodes thicker than 6,3 mm diameter where the value of d is twice the maximum diameter of the electrode as specified by the manufacturer.
The sphere is to be applied to the opening with a force of 30 N ± 10 %.
The springs not designed for carrying the welding current shall be insulated from other metal parts of the ELECTRODE HOLDER.
Conformity shall be checked by visual inspection.
8.2 InsulatIon resistance
The insulation resistance shall, after the humidity treatment, be not less than 1 MQ.
Conformity shall be checked by the following test
a) Humidity treatment
A humidity cabinet is maintained at a temperature t between 20 °C and 30 °C to within ±1 K and a relative humidity between 91 % and 95 %.
The ELECTRODE HOLDER without a cable fitted is brought to a temperature between t and (i+ 4) °C and is then placed for 48 h in the humidity cabinet.
b) Insulation resistance measurement
Immediately after the humidity treatment, the ELECTRODE HOLDER is wiped clean and tightly wrapped in metal foil, covering the external surface of the insulation.
The insulation resistance is measured by application of a DC voltage of 500 V between the live parts and the metal foil, the reading being made after stabilization of the measurement.
The heated rod in a horizontal position is then applied for 2 mm to the insulation at the weakest point (for example, minimum insulation thickness and closest distance to live parts). The heated rod shall not penetrate through the insulation and contact live parts. At the HANDLE, the heated rod shall be applied at the portion with the minimum wall thickness and where internal live parts are closest to the HANDLE surface.
An attempt is made to ignite any gases which may be emitted in the region of the contact point by means of an electric spark or small flame. If the gases are flammable, the burning shall stop as soon as the heated rod is removed.
10 Mechanical requirements
10.1 Welding cable entry
The welding cable entry of an ELECTRODE HOLDER shall have a smoothly rounded edge so as to prevent damage to the cable due to flexing.
Conformity shall be checked by visual inspection.
10.2 Penetration of the welding cable insulation
The design of the ELECTRODE HOLDER shall be such that the insulation of a welding cable can enter to a depth of at least twice the outer diameter of the welding cable with a minimum of 30 mm.
Conformity shall be checked by measurement according to a welding cable of the maximum cross-sectional area as specified by the manufacturer.
10.3 Welding cable connection
The design of the ELECTRODE HOLDER shall be such that welding cables with a cross-sectional area within the range as specified by the manufacturer can be replaced. The connection shall withstand the mechanical stress of the tensile test without separation.
Conformity shall be checked by visual inspection and the following test: The ELECTRODE HOLDER is fitted in accordance with the manufacturer as per the instructions with a welding cable of maximum cross-sectional area. The connection is subjected to 10 pulls with a force of 40 N per mm2 of the cross-sectional area with a maximum of 2 000 N, applied to the welding cable. The force of each pull is gradually increased from zero to the specified value in 1 s and maintained for a further second.IEC 60974-11 pdf download.
