This issue has been gone over (sometimes at length) many times
before.
As a "third party" type myself, I would weigh in by saying that IEC 62353 and DB2006(05) are the ones that get followed by anyone who cares about what he is doing!
But, let's also remember that (as I may have said a few times before) electrical safety testing is not the "be all, and end all", third party engineers generally get called in to carry out work that in-house biomeds are not
resourced* to do, and that EST is most likely carried out
ad nauseum by the in-house techs. But yes, the outside engineer should ensure that EST gets done (one way or another) when appropriate (following repairs,
etc.).
*
Is that a word? Well, it is now.
