Metrel newsletter

MI 3360: Medical test sequences

Standards governing electrical safety are constantly changing and becoming more stringent – to safeguard both the equipment and users. And some are more stringent than other, like those associated with electrical safety of medical equipment. One of them is the IEC / EN 62353:2014 standard that applies to testing of medical electrical equipment and medical electrical systems (full description can be found online).The standard prescribes, amongst other things, allowable values for all relevant measuring functions, measuring diagrams and general requirements.

The standard also includes an Annex B, which contains two images; image B.1 depicting recommended sequence of testing procedures.

The image B.2 on the other hand depicts a sample diagram that helps in deciding which measuring method to use for measuring leakage currents.

On the basis of those two images (i.e. the standard itself), we have prepared (and launched a while ago) application-tailored test sequences especially for testing electrical medical equipment (ME) and electrical medical (ME) systems. However, we found out that the said sequences were organized in a manner that was unfriendly to the average user. Consequently, we have decided to reorganize the test sequences on the basis of the ME equipment or ME system’s protection class.

For every test group that offers the option of choosing an alternative method, we have prepared (on the basis of diagrams from B annex) two test sequences:

Basic: includes direct/differential method at the leakage currents.
Alternative: includes one or more alternative methods at the leakage currents.