Hello,
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.