Overview
EN ISO 22829:2017 - Resistance welding equipment - Transformers - Integrated transformer-rectifier units for welding guns operating at 1 000 Hz (ISO 22829:2017) specifies additional requirements for single-phase inverter transformer–rectifier units used for DC resistance welding. It applies to transformer-rectifier units primarily used in welding guns, designed to operate at 1 000 Hz with a rated input voltage of 500 V or more. The document augments and amends the general transformer requirements in ISO 5826.
Key topics and technical requirements
- Scope and applicability: Additional requirements to ISO 5826 for inverter transformers with rectifiers for DC welding at 1 000 Hz.
- Electrical characteristics: Minimum principal electrical ratings for standard transformer types (output current, no-load voltage, apparent input power) and requirement for manufacturer-supplied curves showing maximum output current vs duty factor and welding time.
- Mechanical dimensions: Specified overall sizes and mounting dimensions for standard types (see Annex B) so units are interchangeable in welding guns.
- Power supply requirements: Rated supply must be delivered by an inverter providing the rated voltage at 1 000 Hz in a waveform suitable for the unit.
- Additional equipment and safety:
- Grounding provision: Case ground terminal and removable link from secondary midpoint to ground.
- Thermal protection: Thermoswitches on rectifier and on primary/secondary windings, with defined wiring colours and positions.
- Output sensing: Provisions for output current sensing coils and output voltage sensing wires.
- Rectifier protection: Specific protective measures for the rectifier assembly.
- Marking and designation: Requirements for primary/output terminal marking and rating plates.
- Testing: Type and routine tests (visual, open-circuit, minimum output under load, cooling circuit, dynamic output behaviour, mechanical strength).
Applications and practical value
- Used where compact, high-frequency transformer-rectifier assemblies are integrated directly into welding guns for DC resistance welding.
- Supports consistent performance, safety, interchangeability and reliable thermal and electrical protection in industrial resistance welding installations.
- Helps manufacturers provide rated output curves and dimensional compatibility, simplifying design and maintenance of welding systems.
Who should use this standard
- Transformer and welding-equipment manufacturers
- Welding-system designers and integrators
- Test laboratories and quality/ compliance engineers
- Procurement specialists specifying transformer-rectifier units for resistance welding
Related standards
- ISO 5826 - Transformers - General specifications
- ISO 669 - Resistance welding equipment - Mechanical and electrical requirements
- ISO 17677-1 - Resistance welding vocabulary (spot, projection, seam)
- IEC 60417 - Graphical symbols for use on equipment
Keywords: EN ISO 22829:2017, resistance welding equipment, transformer-rectifier units, 1 000 Hz, welding guns, ISO 5826, single-phase inverter transformers, DC welding.
