Description

This Standard defines and specifies the characteristics of single-phase resistance welding equipment.

It includes the information required on the equipment nameplate and specifies the test methods to be used to verify the compliance of the equipment with the requirements of this Standard.

Scope

Appendix A gives information on thermal time constants. It is applicable to single-phase resistance welding equipment, including all types of complete portable equipment, for use under the following conditions:

• The altitude shall not exceed 1000 m.
• For water-cooled equipment, the temperature of the cooling water shall not exceed 30°C at the inlet of the equipment and, in the case of air-cooled equipment, none of the following limits shall be exceeded:

• • Maximum ambient air temperature: 40°C.
  • Daily average ambient air temperature: 30°C.
  • Yearly average ambient air temperature: 20°C.

• The pressure of the cooling water shall not be less than that which is necessary to supply the rated flow of cooling water.

This Standard does not apply to transformers sold separately or to capacitor discharge or rectifier equipment. For a given voltage and frequency the characteristics of the equipment are calculated, constructed and tested, as a function of the following operational modes:

• Intermittent operation at a duty cycle (see Clause 1.3.4) of 50%, the values of current and power being termed nominal or rated.
• Continuous operation, the values of current and power being termed continuous.

All voltages and currents shall be expressed as r.m.s. values.