RCD for Bathroom Zone 1

[Alan=UK]

Hi,
I want to renew the wiring going to some lights in the bathroom (zone 1). They are protected by a 30mA RCD on the CU. Is this sufficient, or should there be a separate 30mA RCD dedicated to just those lights?
Thanks,
Alan

 

[Octopus]

Are you a spark ?

 

[westward10]

Are you a spark ?

Hope not with that question.

 

[Octopus]

Hope not with that question.

Are you sure ?

 

[Midwest]

Lets be nice. OP your profile is blocked, what is your competency?

 

[simpson93]

It's sufficient, fittings need to be ip44+

 

[telectrix]

Hi,
I want to renew the wiring going to some lights in the bathroom (zone 1). They are protected by a 30mA RCD on the CU. Is this sufficient, or should there be a separate 30mA RCD dedicated to just those lights?
Thanks,
Alan

before MDJ does it. I'll go first.......GASP. My Flabber is Gasted.

 

[Selfmade]

Two serious questions for the O.P., I'm not meaning to be rude in any way:

1. Are you envisaging an additional RCD in series with the existing one, or putting these lights on a separate circuit protected by its own RCD and not the existing one?

2. What do you see as the advantage of this alteration?

P.S., not meaning to imply competency or otherwise on anyone's part. As with all my answers, the questioner assumes all responsibility for judging their own limits.

 

[Alan=UK]

I'm not an electrician, as is evident from my question. Thanks for giving a sensible answer. I'm not envisaging anything at the moment, but I'm trying to figure out what the rules are. I understand that in zone 1 a 30mA RCD is needed, which is in place in the CU. What I don't know is whether a dedicated one is needed for a zone 1 circuit, or whether the one in the CU is adequate. I don't want to fit one if I don't have to.

 

[Alan=UK]

It's sufficient, fittings need to be ip44+

Thanks. That's what I thought, but wasn't sure whether my interpretation of the rule was correct.

 

[Andy78]

I'm not an electrician, as is evident from my question. Thanks for giving a sensible answer. I'm not envisaging anything at the moment, but I'm trying to figure out what the rules are. I understand that in zone 1 a 30mA RCD is needed, which is in place in the CU. What I don't know is whether a dedicated one is needed for a zone 1 circuit, or whether the one in the CU is adequate. I don't want to fit one if I don't have to.

Does your understanding extend to knowing that work in the zones of a bathroom location is legally notifiable to building control ?

 

[Alan=UK]

Does your understanding extend to knowing that work in the zones of a bathroom location is legally notifiable to building control ?

Yes.

 

[Deleted member 26818]

I'm not an electrician, as is evident from my question. Thanks for giving a sensible answer. I'm not envisaging anything at the moment, but I'm trying to figure out what the rules are. I understand that in zone 1 a 30mA RCD is needed, which is in place in the CU. What I don't know is whether a dedicated one is needed for a zone 1 circuit, or whether the one in the CU is adequate. I don't want to fit one if I don't have to.

RCD protection is required for circuits anywhere in a location containing a bath or shower, not just within zone 1.
RCD protection is also required for circuits that pass through the location.

 

[Selfmade]

I think we should give the OP the benefit of the doubt. For all we know, a cowboy may have told him he needs an extra RCD, or he may just want to know what to ask for or expect when seeking quotes. Or he might be a letting agent wanting to know what to advise his clients. The possibilities are endless, we just don't know.

So with that, and my previous disclaimer in mind:

Alan:

A second 30mA RCD in series with the first will give no advantage as long as the first is working correctly. If it's not, it should be replaced. All the second would do is mean there were two places to check if one trips (undesirable).

Putting the lights in question on a separate circuit with its own separate RCD protection would give the advantage that if either RCD were to trip, lights and any other equipment on the other RCD would be unaffected. But it's not normal to put bathroom zone 1 lights on their own RCD like this. No-one can advise on the specifics without seeing it - there may be some reason why this would be appropriate in your particular installation. But a more typical arrangement for a domestic installation would be one lighting circuit per floor, often on different RCDs from one another. Once again, this is just typical, there may be reasons why your installation is different.

Finally, as others have pointed out, there are other requirements, such as (but not limited to) IP ratings, that need to be taken into account. I'm not going to address these here as they are beyond the scope of the thread (and I'm not going to teach you my whole trade for free!), but whoever is doing the work needs to understand them all and work to them.

Hope that's helpful.

Sam