IEC 60322 (Wirewound Power Resistors)

IEC 60322 ('Fixed power wirewound resistors — sectional specification') is the part of the IEC 60115 family that covers wirewound power resistors above approximately 5 W — the aluminium-housed, tubular ceramic, cement-encased and corrugated parts that appear in motor drives, braking circuits, rail traction and load banks. It tightens or replaces some of the generic IEC 60115-1 tests where wirewound construction needs different validation.

Key requirements include (1) short-time overload at 10× rated power for 5 s with ΔR ≤ ±1 % allowed, (2) endurance at upper category temperature for 1000 h with ΔR ≤ ±3 % (against ±0.5 % for precision IEC 60115 parts — wirewound power parts accept more drift), (3) damp heat at 40 °C / 95 % RH for 56 days, (4) climatic cycling -55 °C / +200 °C or as marked on the part, (5) vibration 10–55 Hz × 1.5 mm amplitude, (6) flame retardancy for resistors used as protective elements, (7) terminal pull/torque test, and (8) marking that must include resistance value, tolerance, power rating, and climatic category.

Braking-resistor purchasing specs from Siemens, ABB, Schneider, Bombardier and CRRC reference IEC 60322 by default. Compliance proves the part survives the worst-case overloads expected in industrial drives, prevents premature wire fatigue, and gives the safety inspector a documented trail. For Hongyi's RX24, RXG24 and corrugated tubular ranges, IEC 60322 testing is performed on representative samples per production lot.