Electrical2Go - Online Electrical Supplier
This official sponsor may provide discounts for members
Advertisement - Content continues below
Advertisement - Content continues below

Discuss Ring main in 4Core SWA in the Electrical Forum area at ElectriciansForums.net

Welcome to ElectriciansForums.net - The American Electrical Advice Forum
Head straight to the main forums to chat by click here:  American Electrical Advice Forum

Evening all

Has anyone ever wired a ring main in 4Core SWA and used the sheath as an earth?

Just looking at wiring some sockets in an industrial unit and wondering whether to do it that way or do a 4mm radial
 
uHeat Banner - Forum Discount Available
This official sponsor may provide discounts for members
Advertisement - Content continues below
Have done, cant remember the situation but seemed a good idea at the time! If a radial will suffice why bother with a RFC?
 

davesparks

-
Mentor
Arms
Esteemed
I have extended an existing ring in 4 core MICC before just to keep the number of visible cables to a minimum in a listed building. But I wouldn't design and install a complete new circuit this way,it seems to defeat the point of a ring to me.

Why do you think that would be a good design for this particular job?
 

Pete999

-
Arms
Esteemed
Used To do it that way using MICC
 

davesparks

-
Mentor
Arms
Esteemed
Used To do it that way using MICC
What was the logic behind wiring a ring and not a radial?
Post automatically merged:

not many sparks can play with that or shown its all FP2000 stuff .still go me old tools .
FP200 for fire alarms etc yes, or bs8436 cable for general purpose circuits. MICC is just too expensive these days to be economical for general use and the other types of cables satisfy the requirements most of the time.
I still work with MICC and install it new as and when it is required for the job, but that's just not very often these days.
 

Pete999

-
Arms
Esteemed
What was the logic behind wiring a ring and not a radial?
Not sure it was just the way we used to do it on some jobs, it's basically the same way as using conduit and singles, one run of tube no return to the CU and no connectors in the socket back box, as you would use if you used 4 core SWA or MICC.
 

davesparks

-
Mentor
Arms
Esteemed
Not sure it was just the way we used to do it on some jobs, it's basically the same way as using conduit and singles, one run of tube no return to the CU and no connectors in the socket back box, as you would use if you used 4 core SWA or MICC.
To my mind it just doesn't seem logical, whether it's in conduit or cable, to run a ring in such a way when you're pretty much cabling it as you would a radial.
 

Paignton pete

-
Arms
Esteemed
Not sure the armoured would have enough CCC for a good enough earth loop impedance. I can see hoe micc would have though.
Post automatically merged:

To my mind it just doesn't seem logical, whether it's in conduit or cable, to run a ring in such a way when you're pretty much cabling it as you would a radial.
Agree it doesn’t seem logical for Cable but conduit is normal practice.
 

Pete999

-
Arms
Esteemed
To my mind it just doesn't seem logical, whether it's in conduit or cable, to run a ring in such a way when you're pretty much cabling it as you would a radial.
Some designers demanded that it should be a RFC
 

davesparks

-
Mentor
Arms
Esteemed
Agree it doesn’t seem logical for Cable but conduit is normal practice.
Is it? I don't think I've ever wired a ring this way in conduit where the conduit is a single run via all the sockets, say along a wall.

Obviously where the conduit is part of a wider conduit and trunking system it often does make sense to wire as a ring.
Post automatically merged:

Some designers demanded that it should be a RFC
Ah I see, so its more likely a case of 'ring = sockets, therefore sockets = ring' attitude than a reasoned technical consideration.
 

Pete999

-
Arms
Esteemed
Not sure it was just the way we used to do it on some jobs, it's basically the same way as using conduit and singles, one run of tube no return to the CU and no connectors in the socket back box, as you would use if you used 4 core SWA or MICC.
Actually when this sort of thing was the, norm and in some cases still is, there were some Sparkies who found it very difficult to understand hoe to do it with both 4 core and conduit, maybe they still are, who knows, I met a few in my time. I enjoyed the conduit method, the only drawback was you nee.ded six drums of cable to do it economically
Post automatically merged:

Is it? I don't think I've ever wired a ring this way in conduit where the conduit is a single run via all the sockets, say along a wall.

Obviously where the conduit is part of a wider conduit and trunking system it often does make sense to wire as a ring.
Post automatically merged:



Ah I see, so its more likely a case of 'ring = sockets, therefore sockets = ring' attitude than a reasoned technical consideration.
Think about it, if you have to run some tube along a long run from the DB on a nice clean wall, would you want to run Conduit from socket to socket, an\n then run another tub \e from the last socket on the run back to the DB? clearly not if you have wits about, different picture if you have other trunking or Conduit available to use for the return leg.
Post automatically merged:

What was the logic behind wiring a ring and not a radial?
Post automatically merged:



FP200 for fire alarms etc yes, or bs8436 cable for general purpose circuits. MICC is just too expensive these days to be economical for general use and the other types of cables satisfy the requirements most of the time.
I still work with MICC and install it new as and when it is required for the job, but that's just not very often these days.
Nave wire RFCs in 5 core FP 200 the same way as if using MICC in overseas locations, not in the UK I hasten to add.
 
Last edited:

Pete999

-
Arms
Esteemed
Why or what information do you have to back up that theory that MICC sheathing would be sufficient as a cpc for this method of wiring.
I ask because when, in the distant past we used MICC 4 core for RFCs it was a case of just use it, it was the norm to do so, can't really see any difference in MICC to SWA after all people now pay more attention to cable, and cpc sizing these days, I personally think that providing the cable is sized and installed correctly there shouldn't be a problem, bur testing will confirm, of course if you are only experienced in PVC/PVC cable all this chit chat may be of little interest, until of course you come across it in your line of expertise.
 
Aico Carbon Monoxide Detectors
This official sponsor may provide discounts for members
Advertisement - Content continues below

Reply to Ring main in 4Core SWA in the Electrical Forum area at ElectriciansForums.net

Wetroom Store - Network Wetroom Suppliers
This official sponsor may provide discounts for members
Advertisement - Content continues below
Advertisement - Content continues below

Electrical Forum

Welcome to the Electrical Forum at ElectriciansForums.net. The friendliest electrical forum online. General electrical questions and answers can be found in the electrical forum.
Advertisement - Content continues below
Top Bottom