Hi. This is probably more of a question to do with disambiguation. When talking about isolator switches and specifying for example 2pole or 4pole for a 3phase Isolator switch what does this mean?

For the 2pole example does it mean that each phase has 2 contactors for each phase ie A-A B-B C-C and that when turn the switch you disconnect each connection?? If so what is the 4 pole switch?

Many thanks!!

 

I'm confused by your terminology disambiguation? Do you mean discrimination?

A 2-pole isolator will isolate a single-phase supply inside a domestic consumer unit.

A 4-pole isolator will isolate all three phases and neautral by which is generally abbreviated to a TP&N isolator.

 

Ok. What about for an MCB, if it is a three phase 2 pole MCB what does that mean. What would it mean if it were a 3 three phase 4 pole MCB??