Rcbo board?

[Mike.J]

Thanks for the feedback Dave, tell me how do they get two sensing coils inside a single module RCBO? On the single module ones I have taken apart the sensing coil is too big to be accommodated on both the line and neutral in a single module, I have also found that two in and two out and no fly lead is no indication of 3mm two pole switching, the line is through the sensing coil, but the neutral is physically attached to the line contacts (electrically separated) and does not have it's own sensor, therefore I surmised the neutral will not trip on overload only on an earth fault, or the other way around?

 

[SBS Dave]

Hi Mike, I think we have a terminology problem. Most Electricians working on single phase would call a particular device 2-pole, when in fact it is 1-pole + N. The mcb senses overcurrent or fault current and trips the circuit. The neutral switch contacts open to achieve isolation only. These contacts are part of the internal DPST switch. Similarly, the RCD senses leakage current and trips the circuit, activating the DPST switch, to achieve P/N isolation. If the device was a multiphase one, you would have 1 sensing coil per phase, but any associated neutral contact would be an integral part of a 3-pole device or a 3-pole + neutral device, (sometimes called a 4-pole device). In neither case, would it have a sensing coil in the neutral.

 

[Mike.J]

Hi Dave, yes terminology is a problem, having been working in France for the last ten years on mostly three phase domestic, three phase RCD's are four pole, any single phase taken from the three phase supply is a true two pole device RCD or MCB's or even RCBO's if you can source them.

 

[Fleeting]

Hi Dave, yes terminology is a problem, having been working in France for the last ten years on mostly three phase domestic, three phase RCD's are four pole, any single phase taken from the three phase supply is a true two pole device RCD or MCB's or even RCBO's if you can source them.

It doesn't really matter where in the world you work rcds operate on the same principle your terminology has nothing to do with it your post in #41 is incorrect.

 

[Andy™]

It doesn't really matter where in the world you work rcds operate on the same principle your terminology has nothing to do with it your post in #41 is incorrect.

seems to be jumping around a bit in post #41, but if he's referring to the neutral not having overload detection in the RCBO, which i think he is, then the post is correct, just badly worded

 

[Fleeting]

seems to be jumping around a bit in post #41, but if he's referring to the neutral not having overload detection in the RCBO, which i think he is, then the post is correct, just badly worded

He is referencing a sensing coil this would be applicable to a rcd where you have three one each for line, neutral and the coil which effectively throws the device when the former create an imbalance. Overcurrent coils are totally different they are not sensing they create sufficient magnetic force to throw the device under fault conditions.

 

[Mike.J]

As Andy said I was referring to RCBO's not having overload protection on the neutral.

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