IEC 60115-4 Ed. 3.0 b:2022

IEC 60115-4:2022 relates to resistors having a rated dissipation typically greater than 1 W up to and including 1 000 W for use in electronic equipment. This document is applicable to fixed power resistors with a maximum surface temperature (MET) higher than the preferred upper category temperature (UCT) of 200 °C.

NOTE: Heat sink resistors, i.e. resistors which in their operation depend on being mounted on a dedicated heat sink, owing to their special temperature conditions, are covered by a special sectional specification (under consideration at the time of publication).

These resistors are typically described according to:

• types (different geometric shapes)
• styles (different dimensions)
• product technology.

The object of this document is to define preferred ratings and characteristics and to select from IEC 60115-1 the appropriate quality assessment procedures, tests and measuring methods and to give general performance requirements for this type of resistor.

NOTE: SMD resistors are covered by IEC 60115-8, regardless of their dissipation.

This edition includes the following significant technical changes with respect to the previous edition:

• The definitions of product technologies and product classification levels of the generic specification, IEC 60115-1:2020, have been adopted;
• A basis for the optional specification of the lead eccentricity of axial leaded resistors has been amended in 4.2;
• The 'period-pulse high-voltage overload test' of IEC 60115-1:2020, 8.3 has been adopted as default test method in 5.3.9, thereby replacing the legacy test 'periodic-pulse overload test of IEC 60115-1:2020, 8.4;
• The revised solderability test of IEC 60115-1:2020, 11.1 has been adopted in 5.3.22 and 5.3.23;
• The combined solvent resistance test of IEC 60115-1:2020, 11.3 has been adopted in 5.3.25;
• The 'endurance at room temperature test' of IEC 60115-1:2020, 7.2 has been reworked and adopted in 5.3.5;
• The 'single-pulse high-voltage overload test' of IEC 60115-1:2020, 8.2, applied with the pulse shape 10/700 in 5.3.8, is complemented with the optional alternative provided by the pulse shape 1,2/50 in 5.4.1;
• Climatic tests for 'operation at low temperature' of IEC 60115 1:2020, 10.2, and for 'damp heat, steady state, accelerated' of IEC 60115 1:2020, 10.5, have been adopted as optional tests in 5.4.5. and 5.4.6, respectively;
• Inclusion of an optional flammability test as 5.4.8;
• New guidance is provided in 6.2 on the presentation of stability requirements with their permissible absolute and relative deviations;
• Acceptance criteria for the visual inspection have been added in 6.5 and in Annex B;
• Visual inspection for the primary and proximity packaging has been added in 6.5.3 and in 7.2;
• The periodical evaluation of termination platings has been added as a new topic of quality assessment in 9.8;
• The revised test clause numbering of IEC 60115-1:2020 has been applied;
• A new Annex C has been added to summarize workmanship requirements for the assembly of leaded power resistors, e.g. as given in the prior IEC 61192 series of standards;
• The informative Annex F on radial formed styles has been amended with details on a formed Z-bend style for surface-mount assembly;
• Furthermore, the informative Annex X has been ad