IEC 60974-12-2011 pdf free download – Arc welding equipment – Part 12: Coupling devices for welding cables
This part of lEC 60974 is applicable to coupling devices for cables used in arc welding andallied processes,designed for connection and disconnection without using tools.
This part of lEC 60974 specifies safety and performance requirements of coupling devices.
This part of IEC 60974 is not applicable to coupling devices for underwater welding.
Normative references
The following referenced documents are indispensable for the application of this document.For dated references, only the edition cited applies.For undated references, the latest editionof the referenced document (including any amendments) applies.
IEC 60050-151，International Electrotechnical Vocabulary (IEV) – Part 151: Electrical andmagnetic devices
IEC 60529，Degrees of protection provided by enclosures (IP Code)
IEC 60974-1，Arc welding equipment – Part 1 : Welding power sources
3Terms and definitions
For the purposes of this document, the terms and definitions given in the lEC 60050-151, theIEC 60974-1, as well as the following apply.
3.1
coupling device
device connecting two welding cables together or connecting a welding cable to weldingequipment
3.2
retaining means
mechanical arrangement that holds the coupling device in position and prevents anunintentional withdrawal, when properly connected
3.3
arc striking and stabilizing voltage
voltage superimposed on the welding circuit to initiate or maintain the arc
4 Environmental conditions
The coupling device shall be capable of operation when the following environmental conditions prevail:
a) range of ambient air temperature:
– during operation: –1 0 °C to + 40 °C;
b) relative humidity of the air: up to 90 % at 20 °C.
The coupling device shall withstand storage and transport at an ambient air temperature of –20 °C to + 55 °C without any damage to function and performance.
5 Type tests
5.1 Test conditions
All type tests shall be carried out on the same new and completely assembled couplingdevice.
All type tests shall be carried out at an ambient air temperature between 10 °C and 40 °℃.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 theinstruments is not specified, but shall be taken into account for the measurement;
b) temperature measuring devices:± 2 K.
5.2Test 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) crush strength, see 9.5;
d) insulation resistance,see 7.2;e) dielectric strength,see 7.3.
The other type tests in this part of lEC 60974 not mentioned above may be carried out in anyconvenient sequence.
6 Designation
Coupling devices shall be designated by the range of cross-sectional area of the weldingcable intended to be connected.The test current at an ambient air temperature of 40 °C isgiven in Table 1 based on maximum cross-section area. The welding coupling device shallaccept the minimum cross-sectional area as given in Table 1. Minimum cross-sectional areamay be reduced to extend the coupling device fitting range.
7 Protection against electric shock
7.1 Voltage rating
Coupling devices shall be rated in accordance with the process as given in Table 2 and the arc striking and stabilizing voltage if applicable.
7.2lnsulation resistance
The insulation resistance of a new coupling device shall, after the humidity treatment, be notless than 2,5 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 and arelative humidity between 91 % and 95 %.
The coupling device without cables fitted is brought to a temperature between : and 1 +4Kand is then placed for 48 h in the humidity cabinet.
b) Insulation resistance measurement
lmmediately after the humidity treatment，the coupling device is wiped clean and tightlywrapped in a metal foil covering the external surface of the insulation.IEC 60974-12 pdf download.