Daylight RCBO-bbery

[equitum]

Why can manufacturers/resellers justify £30 or more for a single RCBO when they can sell, at profit, a 100A 30mA RCD along with a CU, 100A main switch and 10 breakers for £50 ??

Is there anything more expensive in the manufacture of an RCBO that justifies this I wonder ?

Should probably be in trade talk but seems pertinent in light of 17th.

 

[plugwash]

low volume means high prices, hopefully with the 17th demand for RCBOs will go up and prices will go down.

 

[JohnD]

I hope not

I've got crates full of them

 

[GaryMo]

My boss reckons he gets Wylex RCBO's for £22+VAT from a local wholesaler.
For some strange reason it's very difficult to get type B's, all they seem to off is type C's.

 

[JohnD]

I've noticed that too, I presume they are used in some volume in industrial installations.

Not a problem with MEM, obviously.

 

[plugwash]

all volex/wylex/crabtree single module RCBOs seem to be type C afaict. The dual module ones are type B I think though.

For lighting circuits using a C6 shouldn't be a problem (and indeed I would reccomend it) but for power circuit using C types requires more carefull consideration.

 

[Taylortwocities]

This is tongue in cheek -

with RCBOs fitted (and an all RCD 17th edition board) surely we can throw EFLI out of the window. The damn thing with trip by the time the earth fault current gets to 30mA. So maybe it wont matter if its a B, C or D....

Discuss

 

[Softus]

I hope not

I've got crates full of them

Well don't say you weren't warned.

 

[Spark123]

This is tongue in cheek -

with RCBOs fitted (and an all RCD 17th edition board) surely we can throw EFLI out of the window. The damn thing with trip by the time the earth fault current gets to 30mA. So maybe it wont matter if its a B, C or D....

Discuss

As the bulk of RCBOs are electronic RCDs the device has to be able to operate on fault current hence the need for the efli to be low enough to disconnect the magnetic trip on the MCB side.
iirc an electronic RCD requires something like a 50v supply to be able to function which during a fault may not be available.

 

[dingbat]

This is tongue in cheek -

with RCBOs fitted (and an all RCD 17th edition board) surely we can throw EFLI out of the window. The damn thing with trip by the time the earth fault current gets to 30mA. So maybe it wont matter if its a B, C or D....

Discuss

See Table 4.5 on p.50 BS7671:2008

 

[Spark123]

Table 41.5 referring to TT systems?