Abstract :
C. E. Carey: I wish to discuss one or two details in Mr. Blake´s paper. He mentions primarily the single-pole protective unit. He goes into detail and attempts to establish the justification of the multiplicity of parts. However, the question of single-phase or single-pole units cannot be separated from the whole network. Personally, I believe that the multiple unit is the real solution. We have seen that there are certain state laws requiring that we open the entire circuit, rather than allow an unbalance on the networks and produce inductive interference. It is much better, I believe, to clear the entire trouble as quickly as possible rather than take out one phase at a time. The three-pole unit will not occupy as much space in the manhole as three single-pole units. The automatic a-c. network protector is a device which does everything you can expect it to do. It is designed to go into the standard 35-in. manhole cover. The covers of the units are of aluminum, are light and can be handled by one man. Furthermore, if inspection is to be made of these devices the time consumed will be less with three-pole units than with three single-pole units.
