Amendment 3 and Upfront RCD/Overcurrent protection for TT Submain

[shaun1]

Hi all,

Currently looking for something to protect a Sub Main in a house. Supply is TT and consumer unit is to be located aprox 10m away from the incoming service. Sub main will be 25mm armoured, and all final circuits will have RCD protection.

As far as I can see, I will still need an up front 100mA RCD to provide fault protection, along with an 80A Fuse for overcurrent (and fault) protection.

Is there an all in one procuct to achieve this? If not, there is currently a plastic 4way enclosure with a suitable RCD inside, but as everything else is to be replaced/re wired, I assume this will need to br replaced for a non conbustable kind? If we replaced the enclosure with a metal one, are there suitable tail clamps for the incoming meter tails, or would a plastic gland be acceptable?

 

[Pete999]

Hi all,

Currently looking for something to protect a Sub Main in a house. Supply is TT and consumer unit is to be located aprox 10m away from the incoming service. Sub main will be 25mm armoured, and all final circuits will have RCD protection.

As far as I can see, I will still need an up front 100mA RCD to provide fault protection, along with an 80A Fuse for overcurrent (and fault) protection.

Is there an all in one procuct to achieve this? If not, there is currently a plastic 4way enclosure with a suitable RCD inside, but as everything else is to be replaced/re wired, I assume this will need to br replaced for a non conbustable kind? If we replaced the enclosure with a metal one, are there suitable tail clamps for the incoming meter tails, or would a plastic gland be acceptable?

British General Plastic Gland Kit 2x16mm² + 1x16mm² Tails Cable | Consumer Unit Accessories | Screwfix.com - https://www.screwfix.com/p/british-general-plastic-gland-kit-2x16mm-1x16mm-tails-cable/6037p

 

[Pete999]

Hi all,

Currently looking for something to protect a Sub Main in a house. Supply is TT and consumer unit is to be located aprox 10m away from the incoming service. Sub main will be 25mm armoured, and all final circuits will have RCD protection.

As far as I can see, I will still need an up front 100mA RCD to provide fault protection, along with an 80A Fuse for overcurrent (and fault) protection.

Is there an all in one procuct to achieve this? If not, there is currently a plastic 4way enclosure with a suitable RCD inside, but as everything else is to be replaced/re wired, I assume this will need to br replaced for a non conbustable kind? If we replaced the enclosure with a metal one, are there suitable tail clamps for the incoming meter tails, or would a plastic gland be acceptable?

British General Plastic Gland Kit 2x16mm² + 1x16mm² Tails Cable | Consumer Unit Accessories | Screwfix.com - https://www.screwfix.com/p/british-general-plastic-gland-kit-2x16mm-1x16mm-tails-cable/6037p

 

[Leesparkykent]

Lewden switch fuse, change the main switch in the switch fuse for a 100mA S type RCD and gland the tails using a nylon tail gland.

 

[Des 56]

The Iet have given guidance on TT tails
They can be connected directly to a metal clad board before the Rcd as long as the tails have enhanced protection

I personally would fit a S type Rcd in a plastic enclosure fed by the tails, then on to the metal clad switch fuse
A bit junkier but a lot safer in my opinion

 

[shaun1]

Lewden switch fuse, change the main switch in the switch fuse for a 100mA S type RCD and gland the tails using a nylon tail gland.

Perfect. This is what I was after. Just to confirm, one of these will fit in here, and I will have a suitable bit of busbar etc from the main switch?

 

[Leesparkykent]

Perfect. This is what I was after. Just to confirm, one of these will fit in here, and I will have a suitable bit of busbar etc from the main switch?

Yeah...The more recent version had a metal hinged flap rather than the plastic one like in the link.