Discuss Ring main in 4Core SWA in the UK Electrical Forum area at ElectriciansForums.net
not many sparks can play with that or shown its all FP2000 stuff .still go me old tools .Used To do it that way using MICC
Have done, cant remember the situation but seemed a good idea at the time! If a radial will suffice why bother with a RFC?
Used To do it that way using MICC
not many sparks can play with that or shown its all FP2000 stuff .still go me old tools .
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.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.
Agree it doesn’t seem logical for Cable but conduit is normal practice.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 RFCTo 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.
Some designers demanded that it should be a RFC
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 economicallyNot 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.
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.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.
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Ah I see, so its more likely a case of 'ring = sockets, therefore sockets = ring' attitude than a reasoned technical consideration.
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.What was the logic behind wiring a ring and not a radial?
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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.
See here for armoured useNot sure the armoured would have enough CCC for a good enough earth loop impedance. I can see hoe micc would have though.
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.See here for armoured use
https://www.dungannonelectrical.co.uk/dun1-shop/pdf/cable/SWA.pdf
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?
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.
Thanks for that Mate, will come in handy.Hi.
The list below gives the physical CSA of MICC copper sheath when its used as a cpc.
Hope it's of use.
2L1 ****** 5.4 mm2
3L1 ****** 6.7mm2
2L1.5 ****** 6.3 mm2
3L1.5 ****** 7.8 mm2
4L1.5 ****** 9.1 mm2
2H1.5 ****** 11 mm2
3H1.5 ****** 12 mm2
4H1.5 ****** 14 mm2
2L2.5 ****** 8.2 mm2
3L2.5 ****** 9.5 mm2
4L2.5 ****** 11 mm2
2H2.5 ****** 13 mm2
3H2.5 ****** 14 mm2
4H2.5 ****** 16 mm2
2L4 ****** 11 mm2
2H4 ****** 16 mm2
2H6 ****** 18 mm2
3H6 ****** 20 mm2
2H10 ****** 24mm2
3H10 ****** 27mm2
2H16 ****** 30mm2
3H16 ****** 34mm2
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.
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.
I meant 4 core plus cpc sorry mate my badGenerally the CSA of the sheath is over twice the CSA of one conductor in multicore MICC so will always automatically comply as a CPC.
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5 core plus earth or 4 core plus earth?
I meant 4 core plus cpc sorry mate my bad
Just thought I would mention it that's all, not usual to use FP for general circuits is it? nore of a safety circuit type cable I thought. could be wrong though.I know you said that was in other countries, but it wouldn't comply here. BS7671 requires the cpc to be in the form of a ring with the exception of conduit/trunking used as the cpc.
I'm pretty sure this has been the way since at least the 16th edition.
Just thought I would mention it that's all, not usual to use FP for general circuits is it? nore of a safety circuit type cable I thought. could be wrong though.
Did you have CPC's or use the conduit as the circuit protective conductor?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.
Was during a time wne cpc wasn't a normal phrase, as long as it was earthed nobody cred much, so it was the BE Conduit used as the cpcDid you have CPC's or use the conduit as the circuit protective conductor?
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.
Steel has a higher resistance than copper which will affect the maximum length of run for volt drop max ELI etc.R1 + R2 based upon manufacturers information.
, can't really see any difference in MICC to SWA
Yes ! ! ! ! ! !Steel has a higher resistance than copper which will affect the maximum length of run for volt drop max ELI etc.
Why not ? ? ? ?I don’t see any value in wiring in rings through conduit
Why not ? ? ? ?
A 30A supply for what? sockets, a stand alone machine? I'm sorry for the brevity of my answer, I can't see your profile, consequently unable to expand my answer, as I'm unsure of your background.Because if I need a 30a supply I just pull in a 4mm radial , why bother with a ring...
A 30A supply for what? sockets, a stand alone machine? I'm sorry for the brevity of my answer, I can't see your profile, consequently unable to expand my answer, as I'm unsure of your background.
I tend to agree Mate, but it depends on what is specified by the designer isn't it, if a Ring final is asked for you put a ring in, but if you are the designer and feel a Radial is the best option then yes you are correct. The initial question was, I believe has anyone wired a RFC in 4 core SWA, The analogy of wiring in conduit was to distinguish the different methodologyI cant see any reason to pull in 6 x 2.5mm cables into a conduit tube to form a 30/32a ring circuit
Why not just pull in 3 x 4mm singles to achieve the same result
Or am I missing something ?
Yes agreed" " " " "If you use 4 core SWA two of the conductors would have to be crimped/wago or terminated behind each socket.
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