4pole 3phase

[aaelectric]

Hi,
was wondering when you need to use a 4 pole isolator on main switch for 3 phase. Is it just for tt systems?
also do you need 4pole isolators on appliances ie 3 phase cookers etc or is 3 pole ok.
thNks

 

[stef]

I think this came up when neutral conductor became a live conductor whilst the live conductor became the line conductor, so line and neutral are live and have to be isolated together at at least one point.

 

[Knobhead]

From my understanding, if it’s an isolator 4 pole, off switch 3 pole.

 

[aaelectric]

Dont understand what you mean?

 

[Guest111]

Dont understand what you mean?

An on/off switch is for normal day to day use,an isolator is what it says it isolates all line conductors for use during maintenance,repair or emergency.