Enclosure for 30ma rcd

[ricky2609]

Been out to a property to price up repair on a couple of little bits with an old wylex board which has a 100ma RCD main switch. If I was to fit an upfront 30ma rcd before the main board would it have to be in a metal enclosure, haven't needed to do this before and not sure if enclosure would have to be metal or plastic

Thanks

 

[Andy78]

If you were to fit one RCD to cover the whole installation then it would not be compliant.

 

[ricky2609]

I advised a board change would be better but as this is a rental property & landlord does not want to spend would it not be better to make it safer with a 30ma rcd first

 

[Andy78]

I advised a board change would be better but as this is a rental property & landlord does not want to spend would it not be better to make it safer with a 30ma rcd first

It may be safer it terms of increased protection against shock, but may be less safe in the event of a fault due to a complete loss of power. That's why there are regulations to prevent the action you are considering.

 

[davesparks]

I advised a board change would be better but as this is a rental property & landlord does not want to spend would it not be better to make it safer with a 30ma rcd first

There is no regulation which allows you to ignore the other regulations when your customer wants to do a job on the cheap.
If the customer won't pay for the job to be done properly then turn the job down.

 

[westward10]

You haven't stated the repairs you are undertaking.

 

[ricky2609]

You haven't stated the repairs you are undertaking.

No just looking for an option to make install safer before I do anything

 

[westward10]

What are you doing.

 

[ricky2609]

What are you doing.

replace some broken sockets & faulty cooker switch, moving a 240v fan out of zone 1 take down some old lights and replace with pendants

 

[westward10]

Some of that can be deemed maintenance but if you are moving the fan then additional rcd protection will be required, is it not suitable for use in zone 1.

 

[ricky2609]

Some of that can be deemed maintenance but if you are moving the fan then additional rcd protection will be required, is it not suitable for use in zone 1.

I can't verify for sure so advised him to move or change to 12v, as it's vented via attic through celing easy enough to move

 

[Ian1981]

Been out to a property to price up repair on a couple of little bits with an old wylex board which has a 100ma RCD main switch. If I was to fit an upfront 30ma rcd before the main board would it have to be in a metal enclosure, haven't needed to do this before and not sure if enclosure would have to be metal or plastic

Thanks

The guidance on this I was given is a plastic enclosure is acceptable as it doesn't fall into the category of similar switch gear assemblies as a consumer unit would.
Bit of a grey area still I think but the guidance seems to be that if it was TT you can have a upfront time delay 100mA in a plastic enclosure before entering a metal consumer unit.

Change the consumer unit tho rather than fit an upfront rcd protecting the whole installation

 

[westward10]

Who gave such advice.

 

[Ian1981]

Similar switchgear assemblies

The phrase ‘similar switchgear assemblies’ in Regulation 421.1.201 means assemblies used for the same fundamental application as a consumer unit. A consumer unit is defined in Part 2 of BS 7671 as: ‘Consumer unit (may also be known as a consumer control unit or electricity control unit). A particular type of distribution board comprising a type-tested co-ordinated assembly for the control and distribution of electrical energy, principally in domestic premises, incorporating manual means of double-pole isolation on the incoming circuit(s) and an assembly of one or more fuses, circuit-breakers, residual current operated devices or signalling and other devices proven during the type-test of the assembly as suitable for such use.’

An example of a similar switchgear assembly is a three phase distribution board intended to be operated by ordinary persons. This would have to have isolation that interrupts the three incoming line conductors and the neutral, rather than just double-pole isolation as mentioned in the above definition.

Was sent to me via email from our QS whom sought guidance on the matter.

So depends if you think a stand alone rcd fits the bill.

 

[westward10]

What is all this fuss then about separate rcd enclosures on TT not being permitted, not my words unless in metal enclosure.