IEC 60974-11 pdf – Arc welding equipment – Part 11: Electrode holders
The heated rod in a horizontal position is then applied for 2 min to the insulation at the weakestpoint (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 heatedrod 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 pointby means of an electric spark or small flame. lf the gases are flammable, the burning shall stopas soon as the heated rod is removed.
10 Mechanical requirements10.1welding cable entry
The welding cable entry of an ELECTRODE HOLDER shall have a smoothly rounded edge so as toprevent damage to the cable due to flexing.
Conformity shall be checked by visual inspection.
10.2Penetration of the welding cable insulation
The design of the ELECTRODE HOLDER shall be such that the insulation of a welding cable canenter to a depth of at least twice the outer diameter of the welding cable with a minimum of30 mm.
Conformity shall be checked by measurement according to a welding cable of the maximumcross-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-sectionalarea within the range as specified by the manufacturer can be replaced.The connection shallwithstand the mechanical stress of the tensile test without separation.
Conformity shall be checkedby visual inspection and the following test:
The ELECTRODE HOLDER is fitted in accordance with the manufacturer as per the instructions witha welding cable of maximum cross-sectional area. The connection is subjected to 10 pulls witha force of 40 N per mm 2 of the cross-sectional area with a maximum of 2 000 N, applied to thewelding cable. The force of each pull is gradually increased from zero to the specified value in1 s and maintained for a further second.
After the test, the conductor shall not have been displaced by more than 2 mm.This test shallbe repeated with a welding cable having the minimum cross-sectional area as specified by themanufacturer.
lf more than one method of cable fixing is provided, all methods shall be tested.
10.4lmpact resistance
ELECTRODE HOLDERs shall withstand the mechanical stress of the impact tests without visible orfunctional alterations of the electrode clamping device or of the control of this device.
a) Vertical fall
The ELECTRODE HOLDER is fitted with the largest diameter cable in accordance with Table 1. It
is suspended by its welding cable, with the end of the HEAD 1 m above the impact plane.Theimpact plane is a sheet of mild steel, having a thickness of at least 9 mm, in contact with theground.
The ELECTRODE HOLDER is released with its cable in free fall. The test is made three times withthe same ELECTRODE HOLDER .
b) Pendulum swing
For this test, a device according to Figure 3 is used. The.. ELECTRODE HOLDER suspended by itswelding cable is removed from the vertical in a plane normal to the wall.
Released without initial velocity, it strikes a shock piece under the following conditions:
. the shock piece is a mild steel angle bar 40 mm x 40 mm x 5 mm, having an outer radius of
5mm;
the suspension point of the welding supply cable is adjusted 1 m above the angle of thesteel bar so that the part of the ELECTRODE HOLDER which has to undergo the shock is justin contact with the angle of the steel bar when the ELECTRODE HOLDER is hanging freely;during the test, the ELECTRODE HOLDER is displaced from the vertical so that the swing heightis 400 mm.
The ELECTRODE HOLDER is allowed to swing on the angle bar six times: twice on the
HEAD, twice
on the middle part of the HANDLE and twice on the control LEVER ; if the ELECTRODE HoLDER doesnot have a LEVER , twice on parts which are likely to be weak.