French to English Tech/Engineering Energy / Power Generation electricity

The following passage occurs in a definition in a set of regulations on electricity use:

"...un courant de défaut entre un conducteur de phase et la masse, tout en ayant une intensité inférieure à celle d'un courant de court-circuit, peut cependant provoquer l'apparition d'une tension de contact supérieure à la tension limite conventionnelle de sécurité."

I figure this is a phrase which would have a standard equivalent in English, but am not sure what it is ...conventional voltage safety limit? conventional safety limit voltage? Not many Google hits for the possibilities I tried, so perhaps it's something else. Any assistance appreciated.