IEC 60974-13-2021 pdf free download – Arc welding equipment – Part 13: Welding current return clamp.
4 Environmental conditions
The WELDING
CURRENT
RETURN CLAMP shall be capable of operation when the following
environmental conditions prevail:
a) range of ambient air temperature:
during operation: −10 °C to +40 °C;
b) relative humidity of the air: up to 50 % at 40 °C;
up to 90 % at 20 °C.
The WELDING CURRENT RETURN CLAMP shall withstand storage and transport at an ambient air temperature of – 20 °C to + 55 °C without any damage to function and performance.
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 10 °C and 40 °C.
5.2 Measuring instruments
As specified in 5.2 of IEC 60974-1:2017.
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.
Conformity shall be checked by measurement.
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 × 12 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 10 mm from the cable connections. The voltage drop shall not exceed 0,08 V per 100 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.IEC 60974-13 pdf download.