In our Regulations over here, it states that for poly-phase equipment, a system of protection must be used, that in the occurence of a fault on one phase of the equipment, the other phase or 2 phases, must also be disconnected from the supply when the first phase trips.
That's OK if you have a linked MCB on the circuit for each phase, but what if the protection is HRC, with individual fuse-links for each phase.
My question is, do you have this sort of Regulation where you come from?.
And if so, how is compliance normally achieved?. [Linked Image]