6mA RCD for bathroom lights

[brighty73]

Current lighting circuit which the bathroom is on is proteced by 6mA RCD

I notice that the regs state that bathroom electricals need to be protected by a 30mA RCD

Will the existing RCD be OK (since it is more sensitive anyway than the required 30mA - I think ) ??

If I need to mess about adding a new circuit just for the bathroom lights then I'm not going to bother and just leave as is


cheers

 

[EFLImpudence]

Current lighting circuit which the bathroom is on is proteced by 6mA RCD

No such thing.

You are probably looking at a 6A MCB.

RCDs have a test button on them.

A picture would save a thousand words.

 

[Taylortwocities]

I think that you have your terms all mixed up.


The 6A device that you have is an MCB, not an RCD.

To provide 30mA earth leakage protection on the existing circuit, you need to change the 6amp MCB for a 6Amp, 30mA RCBO



BTW, if you are changing syuff in your consumer unit then you'll need to be competent to do this and have the proper test equipment. You'll need an RCD tester to check the new device works properly, for example.

This pic may help you identify the different things

Untitled

• Taylortwocities
• 27 Mar 2010
• 43

Try Google to learn the functional differences.

 

[brighty73]

Cannot get picks on here but...

Consumer Unit is a Wylex wiyth an RCD thing on it with 100A 30mA (with the main on/off switvch next to that/)

Then there are 4 other Wylex switches -- NSB06 (the light circuit) and 3 * NSB 32

At a guess then the circuit os actually 30mA RCD protected - as it says on the tin (???)

 

[EFLImpudence]

Looks like it.

 

[brighty73]

I think that you have your terms all mixed up.


The 6A device that you have is an MCB, not an RCD.

To provide 30mA earth leakage protection on the existing circuit, you need to change the 6amp MCB for a 6Amp, 30mA RCBO



BTW, if you are changing syuff in your consumer unit then you'll need to be competent to do this and have the proper test equipment. You'll need an RCD tester to check the new device works properly, for example.

This pic may help you identify the different things

Untitled

• Taylortwocities
• 27 Mar 2010
• 43

Try Google to learn the functional differences.

Cheers - I certainly won't be doing any of this !!

Just want to know wether the cost of a couple of new lights does not go out of control ( I know I will need a certified spark to install and notify too - for a bit more cost)

 

[vibrobullit407]

Cannot get picks on here but...

Consumer Unit is a Wylex wiyth an RCD thing on it with 100A 30mA (with the main on/off switvch next to that/)

Then there are 4 other Wylex switches -- NSB06 (the light circuit) and 3 * NSB 32

At a guess then the circuit os actually 30mA RCD protected - as it says on the tin (???)

If your main switch is a 30mA RCD then all your circuits are protected via it. I think like the others you are just looking at the MCB.

 

[JohnW2]

Looks like it.

AND

If your main switch is a 30mA RCD then all your circuits are protected via it. I think like the others you are just looking at the MCB.

If, as the OP says, there is a 30A RCD and a Main Switch, it is obviously quite possible that there is a 'split', in which case the 6A MCB (we assume) in question may not be fed from the RCD.

The test for the OP would obvioulsy be to ascertain whether or not pressing the test button on the RCD kills the supply to the bathroom lights.

Kind Regards, John

 

[EFLImpudence]

iThe test for the OP would obvioulsy be to ascertain whether or not pressing the test button on the RCD kills the supply to the bathroom lights.

Yes, good point. I should have said.

Although, as the OP said the RCD was next to the Main Switch it would appear that the RCD covers all the circuits.

 

[JohnW2]

Yes, good point. I should have said. Although, as the OP said the RCD was next to the Main Switch it would appear that the RCD covers all the circuits.

Yes, that does seem probable, particularly if all MCBs are on the same side of the RCD+Main Switch, but it always pays to be sure.

Kind Regards, John.

 

[vibrobullit407]

If, as the OP says, there is a 30A RCD and a Main Switch, it is obviously quite possible that there is a 'split', in which case the 6A MCB (we assume) in question may not be fed from the RCD.

Good spot John missed the next to it part!

With the configuration mentioned I would agree with;

Although, as the OP said the RCD was next to the Main Switch it would appear that the RCD covers all the circuits.

 

[RMS]

Although, as the OP said the RCD was next to the Main Switch it would appear that the RCD covers all the circuits.

but surely that fails to comply with 314.1

 

[JohnW2]

Good spot John missed the next to it part! With the configuration mentioned I would agree with;

Although, as the OP said the RCD was next to the Main Switch it would appear that the RCD covers all the circuits.

As I said to ELFI, you're both very probably right, particularly if all MCBs are on the same side of the RCD/Main Switch. However, it's not totally impossible (maybe someone's attempt to comply with 314.1?) that the lighting MCB is on the same side as the others, but fed directly with a cable from the Main Switch. As I said, it always pays to be sure!

Kind Regards, John.

 

[Taylortwocities]

Cannot get picks on here but...

Of course you can //www.diynot.com/forums/viewtopic.php?t=129539

A picture will solve all these questions.

 

[brighty73]

Managed to get a (rubbish) pic from my phone . .

Untitled

• brighty73
• 13 Feb 2012
• 1