Vitreous Enamelled Wirewound Resistors W20 Series

The W20 Series Vitreous Enamelled Wirewound Resistors are designed for harsh environments and offer high stability, reliability, and power dissipation for their size. They are IECQ-CECC approved and suitable for protection circuits due to their ideal overload characteristics. The resistors feature an impervious lead-free vitreous enamel coating.

Product Attributes

• Brand: TT Electronics (BI Technologies IRC Welwyn)
• Certifications: IECQ-CECC approved, EU Directive 2011/65/EU amended by (EU) 2015/863 (RoHS3)
• Material: Ceramic substrate, vitreous enamel coating, copper clad steel wire (nickel plated and solder-coated) terminations
• Color: Not specified (enamel coating is vitreous)
• Origin: Not specified

Technical Specifications

Construction

A high purity ceramic substrate is assembled with interference fit end caps to which are welded the termination wires. The resistive element is wound on the substrate and welded to the caps; the vitreous enamel protective coating is then applied.

Terminations

Material: Copper clad steel wire, nickel plated and solder-coated. Strength: Meet the requirements of IEC 68.2.21. Solderability: Meet the requirements of IEC 115-1, Clause 4.17.3.2.

Marking

Resistors are legend marked with type reference, resistance value, and tolerance in accordance with IEC 62.

Packaging

W21: Taped in Ammo Packs. W22: Taped and reeled. W23 & W24: Loose packed in boxes.

Application Notes

Termination should not be bent closer than 1.6mm from the body, with a recommended minimum bend radius of 1.2mm. Terminations are solderable to within 4mm from the body. Resistors operated at near maximum temperature cannot be classed as insulated and should not be used in contact with any conducting material. Ensure adequate clearance distance to prevent overheating of adjacent components.

Flammability

All materials used are inorganic and inherently non-burning.

Ordering Procedure Example

W22-3K3JI (W22, 3.3 kilohms 5%, Pb-free)

Key:

• Type: W21, W22, W23, W24
• Value: R (ohms), K (kilohms)
• Tolerance: F (1%), G (2%), J (5%)
• Packing & Termination Finish: I (Standard packing & Pb-free)

For CECC released product, follow the MPN with text indicating the relevant release and style (e.g., W22-3K3JI IECQ-CECC40201-002 KB).