According to EN 60065, 4 Mohms are the minimum insulation resistance for reinforced insulation. BEAB suggests in production that dielectric strength test may be combined with the test for insulation resistance measurement. Thus a test voltage of 3,000Vrms with a calibrated current trip of 0.75mA will detect 4 Mohms.
In the way of identifying the live parts in the same standard, 0.7mApeak under normal operating conditions is maximum allowable limit. For instance, the mains voltage of the U.K. would be 254.4Vrms (240V x 1.06). If this figure is scaled up to 3,000Vrms, the maximum allowable limit should be 5.9mA = (0.5mArms x 3,000) / 254.4.
Apparently these two ways give quite different limits. Which one should be correctly followed in combining these two tests in one?
Advice most appreciated.
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Raymond Li
Dixons Asia Ltd.
Ph: (852)2542 5303 Fax: (852)2541 9067
- Permissible limits of leakage current and insulation resi... Raymond Li
