three pole contactors

[crystal ball]

here is a PDF that explains about contactor overloads..


apparently, there are 2 types of overload, bimetalic thermal ones, and electronic ones..

with the bimetalic thermal ones there is something called a differential trip bar that causes it to trip faster if it loses a phase..

with the electronic ones there is phase monitoring which trips it if it loses a phase..

so there's your reason.. it's so that current runs in all 3 poles to stop it tripping / tripping faster..

Thanks, I never realised that was the reason, every day is a day at school

 

[333rocky333]

Just wondered if we could have just left that slightly damaged pole unused, if the other too were not damaged.

Only until we got a replacement