Just to keep the record straight, CSA are not the only safety agency requiring 100% production line hipot (electric strength) testing. In fact this is required by practically all agencies. Many standards, such as 950 and 1010, have this requirement built right in.
Even if an agency is not involved at all, such as using a self-declaration, the 100% production test is still required if the product is declared to conform with a standard such as 950 or 1010, which require this test. This generally applies to all line powered products and is merely a simple test to ensure that there are no manufacturing related defects, such as faulty primary components or insulation, bent cases, gross misswiring, pinched wires, etc. The 100% production test is usually not the same as the safety (prototype) type test. It is not an impulse test, but a Vrms test at 50 or 60Hz, where the voltage is slowly ramped up, then help, then ramped down. Test voltage and duration vary, depending on the product and the applicable standard. BTW, in the case of non-harmonized standards, the European agencies normally require a more severe test than the N. American agencies. Mr. Leipold is correct in stating that there are exceptions allowed. This test would not be required for SELV dc-powered components, for example. Another possible exception may be a unit with a totally metal-enclosed power supply, where damage to the power supply, or its wiring, during the final assembly is extremely unlikely (of course, the power supply maker is still required to perform 100% hipot). Mr. Leipold is also correct in stating that the test is only required if it is so stated in the CSA Certification Report. Other safety agencies use a similar system, or require this test via separate documentation (check all that stuff they sent you; it's in there!). It is a fact that production line hipot test failures are a fairly common occurrence, so this is a useful (and easy) test. Of course, most safety agencies, including CSA, will consider waiving this test, as long as you can present a logical technical argument. Regards, Egon Varju
