bathrooms rcd

[smu_diddly]

Spartykus.
Something else, that it appears many are not aware of.
Is that if only part of the circuit is protected, then current from an earth fault on the unprotected part of the circuit will by pass the RCD and enter the location.

If the earthing is correct it will not. if done right it will flow down the cpc to the db earth and cause the the mcb or fuse to operate. as the unprotected side will be before the rcd. i cant imagine it going the other way unless the impedance is too great and a earth path exists in the bathroom with a lower impedance.

 

[s.keech]

would that maen r.c.d ing the whole upstairs lighting where the bathroom is

 

[smu_diddly]

if you can great, its covers all areas, just watch for borrowed neutrals if using rcbos.

 

[Deleted member 26818]

If the earthing is correct it will not. if done right it will flow down the cpc to the db earth and cause the the mcb or fuse to operate. as the unprotected side will be before the rcd. i cant imagine it going the other way unless the impedance is too great and a earth path exists in the bathroom with a lower impedance.

The current will take any available path, not only will it flow back to the origin of the installation, it will also enter the location.
Yes hopefully the OCPD will operate within the specified time of 0.4s.
However the Regulations now require the use of a protective device with an operation time of 0.04s, specifically an RCD.

 

[HandySparks]

Not really sure.
Yes Handysparks, here's a link to the Beama RCD handbook: RCD Handbook updated - BEAMA | News.
There's a little chart on page 26.

Thanks, spin.
Interesting chart. You're right, it does show that a FCURCD is not recommended for protecting fixed wiring. However is also says that it IS suitable as an outgoing device on a CU or DB and that it IS suitable for protecting socket outlets of 20A or less. About the same level of ambiguity as the wiring regs then!

 

[DNS1]

I remember having a long discussion with my college tutor (former ECA inspector) about RCDs in bathrooms.

I had always been of the understanding that I only have to RCD protect the circuit being worked on (ie: if installing a shower, protect the shower radial and go home) but he told me that I'd have to make sure the lighting circuit (at least the bathroom section of it) was RCD protected too.

I will never understand exactly why...

 

[Deleted member 26818]

People think my interpretation is over the top.
I think that that particular misunderstanding is due to the wording 'all low voltage circuits of the location'.
Some interpret that to mean, that if you work on one circuit, not only must you provide RCD protection for that circuit, but for all.

 

[rich.250]

I agree with spin, circuits should be protected at the origin. It's that simple.

 

[SPARTYKUS]

Ok.

However.

In the real world, I know many will continue to protect, for example, the bathroom fan (in line) in the loft that supplies the bathroom with an RCD spur as a cheaper solution, based on real life cost pressures. Note Im not pushing it as right or good; neither am I saying it is wrong. Simply that I believe many will see it as a solution that makes a home safer.

The other point being whats installed is protected by an RCD. If something went wrong i'd be suprised if there was any comeback on the contractor concerned. Given the example above.


This point has been covered in many threads- the idea of leaving an install better than when one arrived.

In way of placation & to avoid being beaten senseless in electrician forum cyberspace(!) i do agree however that simply protecting the whole circuit at source is the best idea. In theory! In practise it may turn a £120 job into a much bigger, moretime consuming, and therefore unacceptable-to-the-client job!!

 

[sedgy34]

Rcd spur in the loft protecting the bathroom (new circuit from distribution board for bathroom :smilielol5:you having a laugh!!!

 

[Octopus]

Rcd spur in the loft protecting the bathroom (new circuit from distribution board for bathroom :smilielol5:you having a laugh!!!

Why put it in the loft, place it outside on the wall high up and that way it can double up as the fan 3A fuse and isolation switch for the fan!

 

[SPARTYKUS]

Call me cynical but the members are principally manufacturers who would prefer you to buy more expensive kit like consumer units.

(P26 table)

You cynic!!

 

[morph]

common sense applies
rcd the whole circuit is best
rcd the stuff you work on is sufficient

 

[sedgy34]

Why put it in the loft, place it outside on the wall high up and that way it can double up as the fan 3A fuse and isolation switch for the fan!

just out the way and not in view to look at everytime the customer crawls them stairs!

 

[SPARTYKUS]

just out the way and not in view to look at everytime the customer crawls them stairs!

need one with a little LED then, at least, and flashing :biggrin5:

 

[sedgy34]

need one with a little LED then, at least, and flashing :biggrin5:

you still sulking cause i was in your area lol :ciappa: