Double Pole Rcbo's

[Adrian]

Do double pole rcbo's have overload protection on both poles, the reason i'm asking is can these be used instead of a double pole mcb for caravan use.BS7671 Regulation 721.43.1 Each final circuit shall be protected by an overcurrent protective device which disconnects all live conductors of that circuit.

I have been doing some searches and im surprised how many people are selling caravan consumer units with single pole mcb's fitted.

Also can anyone recommend a good place to buy double pole rcbo's in all sizes.

 

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[Evans Electric]

I 'm thinking , Adrian , that if its DP, as in , both poles are disconnected,  then it would comply .     As you say, most RCBOs are single pole , I know this 'cos my loop  tester  knocks them out every time ,  hence the reason I fit Dual RCD boards . 

I think your comment about SP RCBOs also applies to TT systems. 

 

[Adrian]

The reason they need to have overload protection in both poles is because of reverse polarity on the hook up and not so much isolation.

 

[SBS Dave]

Hi Adrian,

I was certain that my Compacts were true DP, but I took one apart to be sure.

The moving part of the switch mechanism, which breaks both poles in the event of an over current, fault current or out-of-balance detection, is solidly a mechanical 2-pole assembly. This means it must always break both L and N when tripped.

They would therefore be suitable for the application you describe and @ £13.00 + VAT, it is probably the cheapest option.

Hi Evans,

If you were fitting Compact RCBO boards instead of Dual RCD ones, not only would nuisance trips be minimised on your testing, but also your customer would not risk half the house going off on occasions. Having to extend circuit conductors to reach MCBs would probably be eliminated on board replacement jobs and my board would probably fit where the old board fitted. 

SBS Dave