jddevel Posted May 12, 2017 Author Report Share Posted May 12, 2017 1 hour ago, NMEA said: not if you were using conduit wire, it's the sheath that makes the difference Are you referring to the cabling used in houses please? Link to comment Share on other sites More sharing options...
Chewbacka Posted May 12, 2017 Report Share Posted May 12, 2017 (edited) 22 minutes ago, jddevel said: Are you referring to the cabling used in houses please? House wiring (as in twin & earth) is solid core and does not comply with the regs. Arctic flex has individually insulated conductors contained within an outer insulating sheath which is what he is referring to. Added - it's called Arctic as it has good low temperature performance, and flex as it is a proper flexible cable and often used for outside extension leads. Added again - as an example - http://www.toolstation.com/shop/p24117 - blue by convention is used for 230v AC and yellow for 110v AC. Edited May 12, 2017 by Chewbacka Link to comment Share on other sites More sharing options...
NMEA Posted May 12, 2017 Report Share Posted May 12, 2017 1 hour ago, jddevel said: Are you referring to the cabling used in houses please? No, conduit wire is single core but on a boat would still be multi strand. Link to comment Share on other sites More sharing options...
Chewbacka Posted May 12, 2017 Report Share Posted May 12, 2017 (edited) 20 minutes ago, NMEA said: No, conduit wire is single core but on a boat would still be multi strand. Boats will often use what is known as Tri-rated conduit cable. Such as this https://www.cse-distributors.co.uk/cable/high-temperature-cable/tri-rated-cable/ Added - I know you (NMEA) know this, but it was to help the questioner. Sorry if not clear first time. Edited May 12, 2017 by Chewbacka Link to comment Share on other sites More sharing options...
jddevel Posted May 12, 2017 Author Report Share Posted May 12, 2017 1 hour ago, Chewbacka said: House wiring (as in twin & earth) is solid core and does not comply with the regs. This what I understood and have used artic blue. I didn`t understand the expression "conduit wire" but understand multi stranded single core. It`s such lack of understanding on my part which is why I believe it makes more sense to have this part of the fit-out dealt with by a professional. Link to comment Share on other sites More sharing options...
Chewbacka Posted May 12, 2017 Report Share Posted May 12, 2017 1 minute ago, jddevel said: This what I understood and have used artic blue. I didn`t understand the expression "conduit wire" but understand multi stranded single core. It`s such lack of understanding on my part which is why I believe it makes more sense to have this part of the fit-out dealt with by a professional. 12v wiring is fairly logical and simple, but it can get confusing because of the terminology, but ask on here and it can all be explained. Even reading the regs is not so difficult once you get used to the structure of the English used and the specific meaning of the terms used. Link to comment Share on other sites More sharing options...
nicknorman Posted May 12, 2017 Report Share Posted May 12, 2017 Just to reinforce what's been said in this thread, there is no need to seperate mains 3 core flex (e.g. Arctic etc) from 12v wiring, either in relation to the BSS or the relevant ISO (if compliance with the RCD is required). Link to comment Share on other sites More sharing options...
jddevel Posted May 13, 2017 Author Report Share Posted May 13, 2017 12 hours ago, Chewbacka said: House wiring (as in twin & earth) is solid core and does not comply with the regs. This what I understood and have used artic blue. I didn`t understand the Duplicate submission my apologies started typing yesterday-interrupted and then thought I`d deleted it and started again Link to comment Share on other sites More sharing options...
jddevel Posted May 13, 2017 Author Report Share Posted May 13, 2017 So advice what would you suggest in this instance. 3000 watt Victron inverter from this I`ve currently run a 2.5mm artic blue in three separate cables 1) To 240volt to single socket on to washing machine isolator on to single socket. 2) To 240 volt double socket 3) To 240 volt isolator leading to fridge freezer and gas cooker ignition on to single socket Apart from the double socket on the galley worktop to serve say microwave maybe kettle the other single sockets are for say TV laptop etc. althought there are other 12v sockets for TV, laptop. Do I really need those 3 separate circuits to be in ring mains =personally I would have thought not nor would I have to increase their size. "just in case" What does the forum think would be good practice. Link to comment Share on other sites More sharing options...
Chewbacka Posted May 13, 2017 Report Share Posted May 13, 2017 Firstly to comply with the BSS all your sockets should be run from some form of consumer unit, with each circuit having a mcb or fuse. It does not matter - within reason - how many sockets you have as the mcb in the consumer unit will protect the cable, and secondly, the inverter - unless it is a posh one that can boost mains shore power - has an output limit of 3kW which 2.5mm2 cable can handle. You will overload the inverter - which will shut down - before you overload the cable. Same with shore power if your system is designed for 16A supply, as again the 2.5mm2 cable will cope with 16A and the supply mcb will overload and trip before the cable. I have never seen a shore power cable on cruising inland waterways craft bigger than 2.5mm2, but for a residential moored boat, it may well have 32A capacity or bigger. In summary the cable has to be able to cope with the supply capability as well as the load. If the supply to the cable is limited - either by the size of the inverter, shore power supply or the circuit breaker for the cable, then the cable only need to have that capacity. This is why most people have simple radial circuits on boats, though if you have a very long cable you may want to go to a ring to reduce volt drop, but I am not aware of any requirement to do so. Let's see what others think. Link to comment Share on other sites More sharing options...
nicknorman Posted May 13, 2017 Report Share Posted May 13, 2017 12 minutes ago, jddevel said: So advice what would you suggest in this instance. 3000 watt Victron inverter from this I`ve currently run a 2.5mm artic blue in three separate cables 1) To 240volt to single socket on to washing machine isolator on to single socket. 2) To 240 volt double socket 3) To 240 volt isolator leading to fridge freezer and gas cooker ignition on to single socket Apart from the double socket on the galley worktop to serve say microwave maybe kettle the other single sockets are for say TV laptop etc. althought there are other 12v sockets for TV, laptop. Do I really need those 3 separate circuits to be in ring mains =personally I would have thought not nor would I have to increase their size. "just in case" What does the forum think would be good practice. No need for ring mains circuits if you are limiting the whole thing to 16A (normal max shore inlet and around 3500w). But of course you need MCBs or RCBOs rated appropriately for the cable. On our boat we just have one 16A RCBO near the output from the Combi and all the sockets are fed from that via a single 2.5mm 3-core arctic cable, just daisy chained. If you have an immersion heater you might want a seperate feed and breaker for that from the shore side of the Combi bu we went for the whole lot connected after the Combi, which allows the immersion to be run from the Combi if we so wish (engine running, hopefully). Link to comment Share on other sites More sharing options...
jddevel Posted May 13, 2017 Author Report Share Posted May 13, 2017 Thank you Chewbacka and Nicknorman. You`ve confirmed yet again my own view and that the "engineer" since dispensed with- who suggested all the upgrades. To confirm I WILL be using a traditional domestic consumer unit for the 240 service from the inverter with the relevant RCBOs ( as they I believe offer better protection although more expensive) with each circuit daisy chained/radial. Link to comment Share on other sites More sharing options...
WotEver Posted May 13, 2017 Report Share Posted May 13, 2017 It's worth noting that ring wiring for mains is an almost exclusively British thing, introduced at the back end of WW2. Many folk will say that it was introduced due to copper shortages and enabling smaller cables to be used however there is no evidence to support this and it requires a greater length of cable anyway. For a boat it offers no advantages. 1 Link to comment Share on other sites More sharing options...
Paul C Posted May 13, 2017 Report Share Posted May 13, 2017 Slightly greater length - but with half the thickness (half the CSA). I can't think of a single occurrence where you'd use "conduit cable" on a boat - each item, effectively, 'wants' all 3 wires connected to it, be it a socket, fridge, etc - but I'm happy to be enlightened. Link to comment Share on other sites More sharing options...
WotEver Posted May 13, 2017 Report Share Posted May 13, 2017 4 hours ago, Paul C said: Slightly greater length - but with half the thickness (half the CSA) Not as originally written in 1942. It was recommended that the cable should be able to handle 2/3 of the current of the circuit. So only slightly smaller CSA. Link to comment Share on other sites More sharing options...
MtB Posted May 14, 2017 Report Share Posted May 14, 2017 7 hours ago, Paul C said: Slightly greater length - but with half the thickness (half the CSA). I can't think of a single occurrence where you'd use "conduit cable" on a boat - each item, effectively, 'wants' all 3 wires connected to it, be it a socket, fridge, etc - but I'm happy to be enlightened. Surely half the 'thickness' (by which I guess you mean diameter) gives one quarter the CSA. Link to comment Share on other sites More sharing options...
NMEA Posted May 14, 2017 Report Share Posted May 14, 2017 14 hours ago, Paul C said: Slightly greater length - but with half the thickness (half the CSA). I can't think of a single occurrence where you'd use "conduit cable" on a boat - each item, effectively, 'wants' all 3 wires connected to it, be it a socket, fridge, etc - but I'm happy to be enlightened. You are assuming low voltage AC, "conduit wire" or single core multi strand is more often used in extra low voltage DC installations, particularly switches, where the load is one of closely grouped set and has its return via a close by bus bar and single heavy cable back to negative serving a number of devices. In fact this is how I often lay out certain applications on new fit outs and refits. This is particularly useful on nav stations which are rarely found on narowboats but there are many instances where it is useful. Link to comment Share on other sites More sharing options...
adrianh Posted May 14, 2017 Report Share Posted May 14, 2017 You could try Semington dock, K & A if you want professional help, would meet your 4 hour travel limit easily. Link to comment Share on other sites More sharing options...
Featured Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now