UK Extending ring main with wago 222

[Dvyj123]

I have come to extend a ring main on the old wiring (red and black) and have used the wago 222 connectors to extend each leg and extended each leg in a wago junction box and are all connected in the ceiling screwed to joists. The wago 222’s are rated at 32A but when used maintenance free like I have they’re de rated to 20A. The ring is on 32A RCBO, will it be safe with each leg extended with the 222’s even as they’re derated to 20A because they’re in a MF box in the ceiling? Thanks

 

[Spoon]

Welcome to the forum mate.
You will be ok with using 222 for extending ring circuits.
If you are concerned about it you could always swap them for 773 connectors, that are rated at 32A when in the wago boxes.

Edit: You should also have RCD protection for the circuit.

 

[Dvyj123]

Welcome to the forum mate.
You will be ok with using 222 for extending ring circuits.
If you are concerned about it you could always swap them for 773 connectors, that are rated at 32A when in the wago boxes.

Edit: You should also have RCD protection for the circuit.

Thanks appreciate it! What makes them alright to use to extend a ring is it just that each leg doesn’t car 32A so it is not needed to have one rated at that ?

 

[Spoon]

Thanks appreciate it! What makes them alright to use to extend a ring is it just that each leg doesn’t car 32A so it is not needed to have one rated at that ?

Pretty much so.
Does the circuit have RCD protection?

 

[timhoward]

Thanks appreciate it! What makes them alright to use to extend a ring is it just that each leg doesn’t car 32A so it is not needed to have one rated at that ?

The only reg for ring final circuits talks about the current carrying capacity of the cable being not less than 20 amps, and the load current in any part of the circuit not exceeding the cable's capacity for any long periods (paraphrasing wildly).

In other words, 20A is in fact the minimum rating. (see reg 433.1.204 for the whole delightful text)

 

[Markyd]

Just make sure you use a wago box for each leg and not have all four legs in one box as per wago's instructions

 

[Dvyj123]

Yeah it is on a RCBO thanks

 

[littlespark]

Just make sure you use a wago box for each leg and not have all four legs in one box as per wago's instructions

Is that an actual regulation or just because it’s too much of a squeeze?

I’ve extended rfc with a joint in back of socket box. Same thing, isn’t it?

 

[SparkyChick]

Just make sure you use a wago box for each leg and not have all four legs in one box as per wago's instructions

I'm interested in where this nugget is too.

The maintenance free instructions for Wagobox clearly instruct you to reduce the maximum current for the terminals and also the maximum aggregate current which they state is the number of phase conductors * OCPD rating but they also say there are some situations where this may not be the case. I've taken that to suggest that as the maximum current in an RFC is limited to 32A it's within the 50A aggregate limit and therefore it's acceptable to put both joins in one box.

 

[Electro-tech]

https://www.discount-electrical.co.uk/PDFs/Wago/Wagobox.pdf shows application methods.

 

[Markyd]

I'm interested in where this nugget is too.

The maintenance free instructions for Wagobox clearly instruct you to reduce the maximum current for the terminals and also the maximum aggregate current which they state is the number of phase conductors * OCPD rating but they also say there are some situations where this may not be the case. I've taken that to suggest that as the maximum current in an RFC is limited to 32A it's within the 50A aggregate limit and therefore it's acceptable to put both joins in one box.

If you watch this and then do the calculations a 32a supply will take it well over the 50a aggregate

 

[SparkyChick]

https://www.discount-electrical.co.uk/PDFs/Wago/Wagobox.pdf shows application methods.

Interesting this actually shows a ring main extension in the use cases

 

[Markyd]

Interesting this actually shows a ring main extension in the use cases

Where is the pic with 4 legs going into box? Again watch the vid and do the calc.

 

[SparkyChick]

Where is the pic with 4 legs going into box? Again watch the vid and do the calc.

It's not in the video... I was commenting about the documentation by Connexbox....

 

[Markyd]

Just make sure you use a wago box for each leg and not have all four legs in one box as per wago's instructions

My bad......Think i wrote this and confused things...What i mean is a Wago box for each leg of the ring ( 2 cables) as per wago's instructions. Not both legs meaning 4 cables in the same box