Overview
ISO 22829:2017 specifies additional requirements for single‑phase inverter transformers with connected rectifiers used in resistance welding - specifically integrated transformer‑rectifier units for welding guns operating at 1 000 Hz. It amends and supplements ISO 5826 and applies to units intended for DC welding with a rated input voltage of 500 V or more. Where not amended, the general provisions of ISO 5826 remain applicable.
Key topics and technical requirements
- Scope and application: Covers transformer‑rectifier units primarily used in welding guns operating at 1 000 Hz with rated supply ≥ 500 V.
- Power supply: Requires an inverter delivering the rated voltage at 1 000 Hz in a waveform appropriate to the unit characteristics.
- Transformer types & electrical data: Defines minimum principal electrical characteristics (see Table 1 in the standard) for types such as H1, H2, J1–J4, N1, P1, S1, including minimum permanent output current and apparent input power.
- Mechanical dimensions: Prescribes maximum lengths, widths, heights and output terminal sizes (see Table 2 and Annex B).
- Additional equipment:
- Grounding provision and mid‑point link to case ground.
- Thermal protection: thermoswitches on rectifier, primary and secondary windings with specified wiring colors.
- Optional output current sensing coil and output voltage sensing wires with color coding and short‑circuit protection recommendations.
- Protection against welding spatter for rectifiers.
- Marking & designation: Primary and output terminal markings, mid‑point (“MP”), and rating plate requirements (rating plate box 4 must reference ISO 22829:2017).
- Testing requirements:
- Type tests (visual, insulation, DC no‑load, minimum output current with 200 µΩ load, temperature rise, dynamic behaviour, mechanical strength, cooling circuit, etc.).
- Routine tests (reduced set: visual, dielectric, DC no‑load, cooling circuit).
- Dynamic output terminal test (e.g., repetitive loads, duty cycle and deformation limits).
- Cooling: Flow‑rate and pressure‑drop limits and leak‑tightness tests are specified for different types.
Applications and users
- Who uses this standard:
- Manufacturers of resistance welding equipment and integrated transformer‑rectifier units for welding guns.
- OEMs specifying welding guns for automotive, appliance and metal‑joining production lines.
- Test laboratories and quality/acceptance engineers performing type and routine tests.
- Procurement, compliance and R&D teams ensuring equipment meets ISO requirements.
- Practical applications:
- Design verification and acceptance testing of DC welding transformer‑rectifier units operating at 1 000 Hz.
- Ensuring safe grounding, thermal protection, sensing integration and mechanical robustness for welding guns.
- Standardized marking and designation to support maintenance and interoperability.
Related standards
- ISO 5826 - general specifications for transformers (applies unless amended by ISO 22829:2017)
- ISO 669 - mechanical and electrical requirements for resistance welding equipment
- ISO 17677‑1 - vocabulary for spot, projection and seam welding
- IEC 60417 - graphical symbols for equipment markings
Keywords: ISO 22829:2017, resistance welding, transformer‑rectifier, welding guns, 1000 Hz, inverter transformer, DC welding, ISO 5826.