IEC 60974-13-2021 pdf downoad.Arc welding equipment – Part 13: Welding current return clamp.
5 Tests
5.1 Test conditions
All type tests shall be carried out on the same new and completely assembled WELDING CURRENT
RETURN CLAMP .
All type tests shall be carried out at an ambient air temperature between 1 0 °C and 40 °C.
5.2 Measuring instruments
As specified in 5.2 of IEC 60974-1 :201 7.
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 Clause 7;
f) general visual inspection.
The other type tests in this document not mentioned above may be carried out in any convenient sequence.
6 Designation
The WELDING CURRENT RETURN 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 CURRENT RETURN CLAMP shall accept the minimum cross-sectional area as given in Table 1 . Minimum cross-sectional area may be reduced to extend the WELDING CURRENT RETURN CLAMP fitting range.
7 Protection against electric shock – Voltage drop
The WELDING CURRENT RETURN CLAMPS in the new condition shall be capable of satisfactorily passing the voltage test. Conformity shall be checked by the following test: Two WELDING CURRENT RETURN 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 × 75 mm × 1 2 mm. The two clamps shall be positioned so that the centers of the contact points are 260 mm ±20 mm apart. 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, at a distance of 1 0 mm from the cable connections. The voltage drop shall not exceed 0,08 V per 1 00 A of the test current.
8 Thermal rating
8.1 Temperature rise
The temperature rise caused by the current passing through a WELDING CURRENT RETURN CLAMP normally coupled and fitted with an untinned copper welding cable of maximum cross-sectional area as indicated in Table 1 shall not exceed:
a) at the hottest spot of the external surface normally gripped by the operator: 40 K;
b) at the connection of the welding cable to the WELDING CURRENT RETURN CLAMP : 45 K.
NOTE These values are temperature rises in relation to the ambient air temperature (maximum 40 °C).
Conformity shall be checked by the following test:
Voltage drop set-up given in Clause 7 is used for this test. Before beginning the test, pass the test current through the WELDING CURRENT RETURN CLAMP for a period of 1 h. Allow the WELDING
CURRENT RETURN CLAMP to cool to ambient temperature.
A DC current equal to the 1 00 % duty cycle test current given in Table 1 is passed through the WELDING CURRENT RETURN CLAMP until the rate of the temperature rise does not exceed 2 K/h.
During the total test time, the DC current shall be kept constant with a tolerance of ± 2 %.
8.2 Resistance to hot objects
In the case of insulated WELDING CURRENT RETURN CLAMP , the insulation shall be capable of withstanding hot objects and the effects of a normal amount of weld spatter without being ignited.
Conformity shall be checked with a device in accordance with Figure 1.IEC 60974-13 pdf download.