I am sure there are more and that others will chime in, but IEEE and IEC is a good place to start.
As an example for North American market, I would check in the manual for a SEL relay (specifications). I recall seeing a listing there of the various tests (standards). From what I have read of them, they have to due with impulse (dielectric) strength, EMF immunity, etc.
There are other types of tests, such as IEC 61850, that I believe KEMA (independent test lab) performs.
I have read that there is a new IEC standard, directly affecting distance relays that spells out the steps and how things should be tested. I am not aware of a similar IEEE standard.
The link below describes tests in general from Areva/Alstom.
Our company bought numbers of recloser that has no user's references in North America. The controllers failed 3 times during the firmware upgrade by the manufacture's teches, the worst thing was it failed on a simple IEEE time overcurrent curve. The project was thrown to me unfortunately. Due to so many problems I asked the manufacture to take all controllers back and go through a complete product tests. Now they claim they are ready to ship controllers back. I don't have faith of them as they appear lacking serious engineering work. So, is it reasonable to ask them provide their test certificates?
Should be surprised if they didn't offer it to you first. You certainly have a right to it, you can't expect to duplicate the tests if you don't know what they are.
In Mexico, there's an independent lab which is part of the electrical utility.
This lab perform many tests (static and dynamic, as well as having installed a pair of each relay as a backup protection with only alarm-not trip- during a period of time)to each relay that may be used on the transmission, distribution network as well as power stations.
Only after passing satisfactory all the tests, the relay and reclosers are included on a "list"(kind of UL list).
In any bidding, project, upgrading the electrical utility onl accepts "enlisted relays", in that way, the number of "deffects" is reduced and network reliability is increased.
I have attached a list of typical standards applied to relays. You should be able to find the testing standards for any relay in its instruction manual.
