DSH 571 Creepage/clearance
http://decisions.iecee.org/icons/ecblank.gif DSH 571
Creepage/clearance
29
60335-1(ed.4)
Question:
Clause 29 indicates that coatings to Annex J can protect the microenvironment and provide basic insulation. Annex J appears to recognize both Type A and Type B coatings.
IEC 60664-3: 1992 distinguishes between Type A and Type B coatings.
1- Does type A coatings serve to improve the environments from PD2 to PD1?
2- Are creepage distances and clearance requirements applicable between conductors under type B coating?
Decision:
1- Type A coating according to IEC 60664 allows to improve the environment from Pollution Degree (PD) 3 to 1, in the same way it allows the transition from PD 2 to 1.
2- Type B coatings do not require creepage and clearance distances between tracks covered by this type of coating but for type A coating, distance for PD 1 applies.
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