BS EN 60974-13-2011 pdf download.Arc welding equipment Part 13 : Welding clamp.
5 Type tests
5.1 Test conditions
All type tests shall be carried out on the same new and completely assembled welding clamp. All type tests shall be carried out at an ambient air temperature between 10 DC and 40 C.
5.2 Measuring Instruments
The accuracy of measuring instruments shall be:
a) electrical measuring instruments: class 1 (± 1 % of full-scale reading), except for the measurement of insulation resistance and dielectric strength where the accuracy of the instruments is not specified, but shall be taken into account for the measurement:
b) thermometer: ± 2 K.
5.3 Test sequence
The type tests given below shall be carried out in the following sequence:
a) general visual inspection;
b) temperature rise, see 8.1;
C) retaining means, see 9.1;
d) drop withstand, see 9.4;
e) voltage drop, see 7.1;
f) general visual inspection;
The other type tests in this part of IEC 60974 not mentioned above may be carried out in any convenient sequence.
6 Designation
The welding clamp shall be designated by the range of cross-section area of the welding cable intended to be connected. The test current is given in Table 1 based on maximum cross-section area. The welding clamp shall accept the minimum cross-sectional area as given in Table 1. Minimum cross-sectional area may be reduced to extend the welding clamp fitting range.
Two clamps are required for this test. Connect each clamp to a cable of maximum cross- sectional area as indicated in Table 1, by using the method of attachment for which the clamps are designed. Attach one clamp to each end of a clean mild steel plate 300 mm x 75 mm x 12 mm. Connect the other end of the cables to a power source to form a circuit. Pass the test current through both clamps and the plate. The voltage is measured on the two cables, 10 mm away from the clamps. The voltage drop shall not exceed 0,08 V per 100 A of the test current.
7.2 Protection of live parts
The welding clamp can be either protected against unintentional contact with the workpiece or not protected.
Conformity shall be checked by visual inspection.
8 Thermal rating
8.1 Temperature rise
The temperature rise caused by the current passing through a welding clamp normally coupled and fitted with an untinned copper welding cable of maximum cross-sectional area as indicated in Table I shall not exceed:
a) at the hottest spot of the external surface normally gripped by the operator: 30 K;
b) at the connection of the welding cable to the welding clamp: 45 K.
NOTE These values are temperature rises an relahon to the ambient air temperature mazimum 40 C).
Conformity shall be checked by the following test:
Where springs are incorporated in the clamp they shall not constitute part of the current path unless they are permanently by-passed by a fixed conductor capable of carrying the test current given in Table 1.
Conformity shall be checked by visual inspection and the following test:
A welding clamp is fitted in accordance with the manufacturer’s instructions, with a welding
cable of maximum cross-sectional area, 5 m length and its coupling device. The welding cable
is folded to form a bundle not exceeding 0,4 m in length. The welding clamp is attached to a
clean mild steel plate 3 mm thick. The steel plate is hanged In order that cable bundle applies
a vertical longitudinal strength on the welding clamp during I mm,
Test is passed if the welding clamp remains attached to the steel plate.
9.2 WeldIng cable entry
The cable entries of the welding clamp shall be designed so as to prevent damage to the cable due to flexing.
Conformity shall be checked by visual inspection.
9.3 WeldIng cable connection
The design of the welding clamp 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. A welding clamp may be provided with adaptor to enlarge the fitting range.
Conformity shall be checked by visual inspection and by the following test:
A welding clamp is fitted in accordance with the manufacturers 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 1 s.
After the test, the conductor shall not have been noticeably displaced.
This test shall be repeated with a welding cable having the minimum permissible crosssectional area as specified by the manufacturer.
If more than one method of cable fixing Es provided, all methods shall be tested.BS EN 60974-13-2011 pdf download.