UK Seeking advice on quote to replace CU

[brianmoooore]

Actually it's not. It's single pole with a switched neutral.

As the Rexel header correctly states.

 

[Dave OCD]

When it's off both L & N to the relevant circuit are isolated so regardless of what you want to call it it's double pole.

 

[Dave OCD]

I fitted a new Immersion Heater switch last week, it's a 20amp switched live and switched neutral.

 

[brianmoooore]

Don't think I've ever come across a DP RCBO, but a DP MCB has a current sensing element in each pole, and usually consists of two SP MCBs rivetted together with a link between the toggles. A SP & N MCB has a current sensing element in the live pole and just a switch in the neutral.
If the RCBO in question was used on a split phase supply, the RCD element would still work on both poles (unless there was an equal leak to earth on each phase), but one of the phases would not have any overload or short circuit protection.

 

[nicebutdim]

Don't think I've ever come across a DP RCBO, but a DP MCB has a current sensing element in each pole, and usually consists of two SP MCBs rivetted together with a link between the toggles. A SP & N MCB has a current sensing element in the live pole and just a switch in the neutral.
If the RCBO in question was used on a split phase supply, the RCD element would still work on both poles (unless there was an equal leak to earth on each phase), but one of the phases would not have any overload or short circuit protection.

I remember a discussion from some time back, in which it was discovered that certain 'DP' (2 module) RCBOs were also SPSN.

 

[timhoward]

To be honest we probably aren't doing a lot to help the OP ask a clear question of his electrician!
The point is that when you turn the thing off (or it trips) both Line and Neutral are broken so the circuit is completely isolated and any faults can't cause issues elsewhere. While the learned people are right, to be honest "double pole" is probably the term that is most likely to be instantly understood by the average domestic sparks.
CEF call the Lewden RCBOs "single pole" vs "single pole and neutral", the latter being the one's that would be best to use.

(to add to the confusion Fusebox SPN units do not break the Neutral and they call the one's that do DP ....!)

 

[mainline]

Actually it's not. It's single pole with a switched neutral. But I know what u mean

Actually, it's a DP Rcbo that has no current sensing on the neutral side.
But i know what you mean

 

[mainline]

Don't think I've ever come across a DP RCBO, but a DP MCB has a current sensing element in each pole, and usually consists of two SP MCBs rivetted together with a link between the toggles. A SP & N MCB has a current sensing element in the live pole and just a switch in the neutral.
If the RCBO in question was used on a split phase supply, the RCD element would still work on both poles (unless there was an equal leak to earth on each phase), but one of the phases would not have any overload or short circuit protection.

https://pdg.cef.co.uk/downloads/pdg/cudis_ro2_datasheet/cudis_ro2_datasheet.pdf

Electronic type
• Residual current characteristic: AC
• No of poles: 2 (L and N)
• Trip curves: B and C
• Rated voltage: 240V AC, 50/60Hz
• Short circuit capacity: 10kA
• Rated current (A): 6, 10, 16, 20, 25, 32, 40, 50, 63
• Rated residual operating current, In (mA): 30
• Electrical endurance: 4000 cycles
• Mechanical endurance: 10000 cycles
• Conforms to: IEC/EN 610009-1