Ring main extension

[Tileta]

Hi
I would appreciate some advice on a ring main circuit in a domestic property.

My single story house has a 4mm ring main circuit for the socket outlets. At some stage this circuit has been extended to include the garage and a utility room. I notice that the extension has been done in 4mm+1.5 cable whereas the original circuit (old colours) has a larger section earth core.

The consumer unit is relatively new and has a 32a RCD feeding the ring main.

Can anyone reassure me that the smaller earth core of the 4mm+1.5 cable is adequate in this arrangement.

Thanks in anticipation

Tileta.

 

[Spudnik]

Hi Tileta and welcome to www.electriciansforums.net!

 

[Octopus]

Only somebody with a MFT tester, adequate knowledge and access to site could give you a definitive answer

 

[telectrix]

difficult to assess without actually measuring the pefc . the cpc needs to be able to withstand a fault current without damage.

 

[onions1066]

Hi
I would appreciate some advice on a ring main circuit in a domestic property.

My single story house has a 4mm ring main circuit for the socket outlets. At some stage this circuit has been extended to include the garage and a utility room. I notice that the extension has been done in 4mm+1.5 cable whereas the original circuit (old colours) has a larger section earth core.

The consumer unit is relatively new and has a 32a RCD feeding the ring main.

Can anyone reassure me that the smaller earth core of the 4mm+1.5 cable is adequate in this arrangement.

Thanks in anticipation

Tileta.

How old is the wiring? You sure it's not stranded 2.5?

 

[Octopus]

How old is the wiring? You sure it's not stranded 2.5?

Or imperial.

 

[onions1066]

Yes or imperial

 

[Tileta]

Onions1066

The wiring assuming it's the original, was done in the early 60's. It is standed and I will have to check the cross section.

Many thanks
Tileta

 

[Des 56]

Has the circuit been extended as a ring main or radial extension

 

[telectrix]

it's probably not 4mm but 7/029. that's just a tad over 2.5mm.

 

[Tileta]

The cable would appear to be imperial, it has 7 strands at 0.73 diameter = 2.93mm2. The extension is a ring not a radial.

Tileta

 

[telectrix]

2.9mm2 appears to be 7/029 as i said. current capacity slightly higher than 2.5mm2. and far better quality cable.

 

[Tileta]

Yes, thanks for that.

So with due deference to the replies reguarding testing, presumably I don't need to worry about the suitability of the 4mm+1.5 cable?

Tileta

 

[telectrix]

i wouldn't worry as long as all connections are good.

 

[chrish_1977]

Sounds like it is stranded 2.5, however need an electrician to have a proper look, no point guessing