Other than the physical size and cost*, is there any other reason to
choose between a unit with a main switch +RCBOs and a unit with main
switch +RCD +MCBs?

Need to fit a consumer unit in a small space and very restricted on the
length (though depth and height not a problem).
*Only needs to have 1*6A, 1*32A and 1*40A, so the cost issue of RCBOs vs
MCBs isn't important.

On Saturday, 20 August 2016 14:46:35 UTC+1, Lee wrote:
Other than the physical size and cost*, is there any other reason to
choose between a unit with a main switch +RCBOs and a unit with main
switch +RCD +MCBs?

Need to fit a consumer unit in a small space and very restricted on the
length (though depth and height not a problem).
*Only needs to have 1*6A, 1*32A and 1*40A, so the cost issue of RCBOs vs
MCBs isn't important.

size, cost & discrimination.


NT

On 20/08/2016 14:59, wrote:

Snip

size, cost & discrimination.


NT


I just noticed the other thread that I missed before, so basically
opting for the main switch +3*RCBOs is perfectly fine?

Lee

In article ,
Lee wrote:
Other than the physical size and cost*, is there any other reason to
choose between a unit with a main switch +RCBOs and a unit with main
switch +RCD +MCBs?

Need to fit a consumer unit in a small space and very restricted on the
length (though depth and height not a problem).
*Only needs to have 1*6A, 1*32A and 1*40A, so the cost issue of RCBOs vs
MCBs isn't important.

RCBOs are preferable as a 'leakage' fault only takes out that circuit.
With a whole CU RCD, the same fault takes out all. Also helps with fault
finding - as you'll know which circuit the leakage is in.

--
He who laughs last, thinks slowest*

Dave Plowman London SW
To e-mail, change noise into sound.

On Saturday, 20 August 2016 15:03:22 UTC+1, Lee wrote:
On 20/08/2016 14:59, tabbypurr wrote:

size, cost & discrimination.

I just noticed the other thread that I missed before, so basically
opting for the main switch +3*RCBOs is perfectly fine?

It's better than MCBs as Dave explained.


NT

On 20/08/2016 14:46, Lee wrote:
Other than the physical size and cost*, is there any other reason to
choose between a unit with a main switch +RCBOs and a unit with main
switch +RCD +MCBs?

Need to fit a consumer unit in a small space and very restricted on the
length (though depth and height not a problem).
*Only needs to have 1*6A, 1*32A and 1*40A, so the cost issue of RCBOs vs
MCBs isn't important.


All RCBO solutions are usually "best" in most circumstances. The only
exception being if you specifically wanted a circuit without RCD
protection - but in that case you could simply drop an RCBO for a MCB.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Sat, 20 Aug 2016 18:40:50 +0100, John Rumm
wrote:

On 20/08/2016 14:46, Lee wrote:
Other than the physical size and cost*, is there any other reason to
choose between a unit with a main switch +RCBOs and a unit with main
switch +RCD +MCBs?

Need to fit a consumer unit in a small space and very restricted on the
length (though depth and height not a problem).
*Only needs to have 1*6A, 1*32A and 1*40A, so the cost issue of RCBOs vs
MCBs isn't important.


All RCBO solutions are usually "best" in most circumstances. The only
exception being if you specifically wanted a circuit without RCD
protection - but in that case you could simply drop an RCBO for a MCB.

In a normal domestic installation, what would a circuit have to supply
to make that a sensible option?



--

Graham.

%Profound_observation%

In article ,
Graham. wrote:
All RCBO solutions are usually "best" in most circumstances. The only
exception being if you specifically wanted a circuit without RCD
protection - but in that case you could simply drop an RCBO for a MCB.

In a normal domestic installation, what would a circuit have to supply
to make that a sensible option?

Some things can 'leak' slightly. Enough to trip an RCD while working
normally. Things like immersion heaters - that type of heating element.
And multiple SMPS - a room full of computers.

Now you could argue a heating element shouldn't 'leak' - but it's unlikely
to cost more to run if it is switched off when not in use. Nor does
something permanently wired usually present a safety hazard.

--
*America is so advanced that even the chairs are electric.

Dave Plowman London SW
To e-mail, change noise into sound.

On 21/08/16 14:13, Graham. wrote:
On Sat, 20 Aug 2016 18:40:50 +0100, John Rumm
wrote:

On 20/08/2016 14:46, Lee wrote:
Other than the physical size and cost*, is there any other reason to
choose between a unit with a main switch +RCBOs and a unit with main
switch +RCD +MCBs?

Need to fit a consumer unit in a small space and very restricted on the
length (though depth and height not a problem).
*Only needs to have 1*6A, 1*32A and 1*40A, so the cost issue of RCBOs vs
MCBs isn't important.


All RCBO solutions are usually "best" in most circumstances. The only
exception being if you specifically wanted a circuit without RCD
protection - but in that case you could simply drop an RCBO for a MCB.

In a normal domestic installation, what would a circuit have to supply
to make that a sensible option?




Fire alarm system (separate to lights), medical equipment and
refrigeration are all options.

On 21/08/2016 14:13, Graham. wrote:
On Sat, 20 Aug 2016 18:40:50 +0100, John Rumm
wrote:

On 20/08/2016 14:46, Lee wrote:
Other than the physical size and cost*, is there any other reason to
choose between a unit with a main switch +RCBOs and a unit with main
switch +RCD +MCBs?

Need to fit a consumer unit in a small space and very restricted on the
length (though depth and height not a problem).
*Only needs to have 1*6A, 1*32A and 1*40A, so the cost issue of RCBOs vs
MCBs isn't important.


All RCBO solutions are usually "best" in most circumstances. The only
exception being if you specifically wanted a circuit without RCD
protection - but in that case you could simply drop an RCBO for a MCB.

In a normal domestic installation, what would a circuit have to supply
to make that a sensible option?

Typically things like:

Sub-mains - feeding other CUs (so you can maintain discrimination
between circuits in the slave CU)

Circuits where you want a very low trip risk (Boiler, frost protection,
or freezer supply etc)

High reliability circuits - fire protection, medical equipment, some
lifting gear etc.

Circuits that tend to have high leakage currents combined with very low
shock risks like mineral insulated heating elements in damp environments
(immersion heaters, cookers etc)



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 2016-08-21 13:13:56 +0000, Graham. said:

On Sat, 20 Aug 2016 18:40:50 +0100, John Rumm
wrote:

On 20/08/2016 14:46, Lee wrote:
Other than the physical size and cost*, is there any other reason to
choose between a unit with a main switch +RCBOs and a unit with main
switch +RCD +MCBs?

Need to fit a consumer unit in a small space and very restricted on the
length (though depth and height not a problem).
*Only needs to have 1*6A, 1*32A and 1*40A, so the cost issue of RCBOs vs
MCBs isn't important.


All RCBO solutions are usually "best" in most circumstances. The only
exception being if you specifically wanted a circuit without RCD
protection - but in that case you could simply drop an RCBO for a MCB.

In a normal domestic installation, what would a circuit have to supply
to make that a sensible option?


PV

"bruceb" wrote in message ...
On 2016-08-21 13:13:56 +0000, Graham. said:

On Sat, 20 Aug 2016 18:40:50 +0100, John Rumm
wrote:

On 20/08/2016 14:46, Lee wrote:
Other than the physical size and cost*, is there any other reason to
choose between a unit with a main switch +RCBOs and a unit with main
switch +RCD +MCBs?

Need to fit a consumer unit in a small space and very restricted on the
length (though depth and height not a problem).
*Only needs to have 1*6A, 1*32A and 1*40A, so the cost issue of RCBOs
vs
MCBs isn't important.


All RCBO solutions are usually "best" in most circumstances. The only
exception being if you specifically wanted a circuit without RCD
protection - but in that case you could simply drop an RCBO for a MCB.

In a normal domestic installation, what would a circuit have to supply
to make that a sensible option?


PV



Not supplying a non RCD way is a good way to upset them when they do their
install:-)


--
Adam