wiring looms

[jddevel]

Apart from LoomTec any one know of a qualified boat electrician who can produce a narrow boat wiring loom for a sailaway. Either located not to far from Swanley Bridge Marine or from Bristol. Thank you in anticipation..

[cuthound]

This sub-forum is meant for technical advice relating to the use of the forum or your forum account.

 

I suggest you ask a mod to move this to the "Equipment" sub-forum, where more people will see it.

[Paul C]

Why on earth would you try to produce a narrowboat wiring loom off the boat, then subsequently fit it? It sounds like a recipe for disaster, with cables either ending up too short, too long (wasteful) or not terminated. The too short/long scenario wouldn't be too bad if it were simply a pair of wires run for (eg) lights or water pump or something, but imagine if they got the location of the circuit breaker board just a few inches out, resulting in either a stretched mass of wires, or loads of bulky excess curving round awkwardly?

 

Sure, for cars, producing (or rather, copying) a loom for eg a classic car would be feasible; or the original manufacturer being able to standardise the design then produce the loom elsewhere then clip/click it in place during mass production; but narrowboats are designed and constructed quite differently.

ETA rereading the question its not clear whether you want a completed loom to buy, or just if you want someone to come onto the boat and effectively create a wiring loom (ie run wires) in-situ. It just seems a bit odd calling it a wiring loom, which I suppose it is but isn't really the way its described.

[bottle]

Reported. see post #2

 

Otherwise as per post #3

[Tiggs]

I don't think anyone does a narrowboat wiring with a loom, although the engine and it's control panel may each have one, the variation in design and layout means looms are not a good idea. Even engine to control panel length varies from about 4 ft to 30 ft! Makers of hire boats may have some partial looms they use, but I can't see how making individual ones would be useful.

 

(I used to work in a factory that made looms for Lancaster bombers during the war - these would be all the same so once one was proven OK you could make the rest of them off-line.)

 

I suggest you design the wiring layout and estimate what cable you need and buy it in reels from somewhere like

 

http://www.vehicle-wiring-products.eu

Edited October 3, 2016 by Tiggs

[jddevel]

Having taken advice from others and researched other links in previously asked questions I have decided to go with LoomTec. For those who appear confused by my topic listing I firstly apologies if it was incorrectly placed in the wrong forum. After all I`m only human and unlike some prone to mistakes. As to the use of a loom a visit to LoomTecs website might enlighten. They visit the craft along with the customer- me. measure up and supply the correct cabling along with diagram/schematic colour coded etc and more importantly certificated to conform to the BSC and Recreational Directive!!! Moderator please close this to further comment.

[Tony Brooks]

I agree that buying one made up off the boat is either going waste a lot of cable or be just asking for problems, especially when the maker thinks they know better than the fridge manufactures.

 

If you do get a ready made on insist in writing that they use the fridge manufacturers recommended size of cable, not what they calculate will be OK.

 

I screw little plastic blocks designed to accept a zip tie along the line of the wiring at around 150mm centres (I think the BSS demand a minimum of 600mm but check) and fit zipties in very loosely loop. Then you can run the cables you need through the ziptie loops. When they are all in and tested just tighten the zip ties and you have a correctly supported loom.

 

I agree that buying one made up off the boat is either going waste a lot of cable or be just asking for problems, especially when the maker thinks they know better than the fridge manufactures.

 

If you do get a ready made on insist in writing that they use the fridge manufacturers recommended size of cable, not what they calculate will be OK.

 

I screw little plastic blocks designed to accept a zip tie along the line of the wiring at around 150mm centres (I think the BSS demand a minimum of 600mm but check) and fit zipties in very loosely loop. Then you can run the cables you need through the ziptie loops. When they are all in and tested just tighten the zip ties and you have a correctly supported loom.

 

 

 

PS - Note what I said about fridge wires.

[Paul C]

Having taken advice from others and researched other links in previously asked questions I have decided to go with LoomTec. For those who appear confused by my topic listing I firstly apologies if it was incorrectly placed in the wrong forum. After all I`m only human and unlike some prone to mistakes. As to the use of a loom a visit to LoomTecs website might enlighten. They visit the craft along with the customer- me. measure up and supply the correct cabling along with diagram/schematic colour coded etc and more importantly certificated to conform to the BSC and Recreational Directive!!! Moderator please close this to further comment.

 

That's interesting. I've not visited the website though, but it sounds like they're approaching it in a logical/thorough fashion. After they have visited (once, I presume?) if you find errors do they offer to redo the whole loom (if its wrapped or contained within trunking) or to visit to re-measure, possibly unwrap individual wires from trunking, add a replacement wire eg if its simply too short, then re-wrap it all up neatly? And if its a whole loom replacement, what happens if you've installed 95% of the wiring? Also what about eg passages through bulkheads, where the wires fit nicely but the connectors either end wouldn't fit through the hole? Or are all the connectors single wire ones (multi-connectors can make a lot of sense in certain situations).

 

I know I pointed out in post #3 the issue of cable length, but there's other issues too - as detailed above. And things like correct routing and passing through bulkheads. For example if your wiring loom were to incorporate wires for solar panels, how do they do the connection from inside to outside boat, etc?

 

Anyway, best of luck with LoomTec, would be interesting to know if the advantages of a (basically) plug & play system offers other genuine benefits and they can get round the inherent problems of trying to make a loom off the boat then making it nice on the boat.

[WotEver]

As far as I can tell from the photos on their site the cables are unterminated.

 

http://www.loom-tech.co.uk/index.php?route=information/information&information_id=14

 

Looking at the loom loosely draped in place and then considering how the fitout is going to work around it it's certainly not an approach I'd take.

 

Tony

 

They state that they've 'wired over 500 narrowboats'. I'd place good money that they've not 'supplied over 500 looms'.

[Murflynn]

 

I agree that buying one made up off the boat is either going waste a lot of cable or be just asking for problems, especially when the maker thinks they know better than the fridge manufactures.

 

If you do get a ready made on insist in writing that they use the fridge manufacturers recommended size of cable, not what they calculate will be OK.

 

I screw little plastic blocks designed to accept a zip tie along the line of the wiring at around 150mm centres (I think the BSS demand a minimum of 600mm but check) and fit zipties in very loosely loop. Then you can run the cables you need through the ziptie loops. When they are all in and tested just tighten the zip ties and you have a correctly supported loom.

 

 

PS - Note what I said about fridge wires.

 

http://www.ebay.co.uk/itm/Cable-Tie-Cradle-Mounts-Heavy-Duty-Black-Natural-Various-Sizes-/222181314728?var=&hash=item33bb09d0a8:m:m3vLDCERbXuIKO2mfdEAIuw

[WotEver]

http://www.ebay.co.uk/itm/Cable-Tie-Cradle-Mounts-Heavy-Duty-Black-Natural-Various-Sizes-/222181314728?var=&hash=item33bb09d0a8:m:m3vLDCERbXuIKO2mfdEAIuw

Yup, those are the ones I use and probably Tony B too

Edited October 3, 2016 by WotEver

[jddevel]

Thank you for your contributions. My problem is that I`m going to complete a "fit-out" in Cornwall. Well away from narrowboat electricians especially those familiar with sailaway vessels. I`m also concerned about Recreational Directive. During over 40 years of house building I have installed numerous complete installations. But not 12 volt and wonder in my "ignorance" whether the time consumed researching requirements regarding cable sizing etc. may be better used. It is strange that for example in one topic I read that it was suggested that cabling could be installed in insulation. That as I understand is ill advised as cabling can give off heat no matter how small and this should be allowed to dissipate. Even under ground mains cabling should not be ducted to allow such heat to evaporate. For those of you who have carried out complete wiring installations how did you go about creating your task. Incidentally can cable be purchased in short lengths. Can`t allowances in design be made to cover future "add ons" ( solar, additional equipment) via accessible junction boxes and the use of pre-installed draw strings in ducting?

Thank you

[Graham Davis]

I would have thought a vehicle wiring expert would have been able to do a similar job, and aren't there any electricians doing boats built in Cornwall?

[Murflynn]

Thank you for your contributions. My problem is that I`m going to complete a "fit-out" in Cornwall. Well away from narrowboat electricians especially those familiar with sailaway vessels. I`m also concerned about Recreational Directive. During over 40 years of house building I have installed numerous complete installations. But not 12 volt and wonder in my "ignorance" whether the time consumed researching requirements regarding cable sizing etc. may be better used. It is strange that for example in one topic I read that it was suggested that cabling could be installed in insulation. That as I understand is ill advised as cabling can give off heat no matter how small and this should be allowed to dissipate. Even under ground mains cabling should not be ducted to allow such heat to evaporate. For those of you who have carried out complete wiring installations how did you go about creating your task. Incidentally can cable be purchased in short lengths. Can`t allowances in design be made to cover future "add ons" ( solar, additional equipment) via accessible junction boxes and the use of pre-installed draw strings in ducting?

Thank you

fact is, you can make it as complicated as you wish, by introducing imaginary problems.

 

the best way to wire any boat is to get on board with some cable and components and get on with it.

 

you can try to do it at a desk at home but that is limited to cable sizing and schematic diagrams.

[WotEver]

Yes, cable can be installed in an insulated space and it is incorrect to state that underground mains cables should not be ducted. In fact, non-armoured underground mains cables MUST be ducted.

 

In the case of mains cables where they are most often sized according to the current carrying capacity of the cable there are various derating tables available that consider such installation factors as bunching, conduit, raised temperature environments etc.

 

In the case of 12V circuits where the cable size is dictated according to voltage drop the current capacity will almost always be way above the actual current draw and no derating will be necessary.

 

Yes, cable can be purchased by the metre.

 

Tony

 

Obviously extra cables and junction points can be incorporated for future expansion but the moment you add anything yourself the CE certification that you deem so important is then negated.

[ditchcrawler]

I would go for a duct/trunking the length of the boat that can have whatever covers it removed so that it is accessible. that give you half a chance of adding things, the other half is if you can get from that duct to where you want to go. If you do plan to put solar panels on at some point make provision for getting the cables through the roof, like wise with aerials, radio, tv, wifi and even a couple of spares. Somewhere you can get the cable through.

Edit

Also consider a high level power outlet. I wish I had put one in to feed power to the MiFi unit instead of trailing a cable down. Some USB sockets are also handy. Two way light switches so you can put lights on from ether end are useful as well.

Edited October 3, 2016 by ditchcrawler

[jddevel]

I know not really on topic but why did Western Distribution insist I removed a domestic supply cable from ducting quoting the reason referred to above and just ensure that the location was suitable marked with advisory tape at the correct depth over the cable length. I would also add about 10 years ago whilst operating a digger in a location I was advised by again Western Distribution via their draftsmen's under ground location plan there was no cabling, I "skimmed" off the red sheathing from a 11000kva underground cable. I phoned to tell them of their error and I stated I`m lucky it is armoured. Their reply It isn`t. I wonder why they said that?

[Murflynn]

I know not really on topic but why did Western Distribution insist I removed a domestic supply cable from ducting quoting the reason referred to above and just ensure that the location was suitable marked with advisory tape at the correct depth over the cable length. I would also add about 10 years ago whilst operating a digger in a location I was advised by again Western Distribution via their draftsmen's under ground location plan there was no cabling, I "skimmed" off the red sheathing from a 11000kva underground cable. I phoned to tell them of their error and I stated I`m lucky it is armoured. Their reply It isn`t. I wonder why they said that?

11kV ??

 

Western Power Distribution took over from SWEB. They do not necessarily have all the cable location drawings for cables which were installed by previous generations, before the use of computers where multiple layers of utilities information can be stored on a single plan. The moral is that NO excavation should be undertaken without clearing the area with a CAT or similar (cable location tool).

[WotEver]

I know not really on topic but why did Western Distribution insist I removed a domestic supply cable from ducting quoting the reason referred to above...?

No idea, why don't you ask them which part of the 17th Regs they were referring to? Cable surrounded by soil isn't going to be any less warm than cable inside ducting inside soil, plus it has no mechanical protection.

 

Tony

[cuthound]

Perhaps he meant tiling rather than ducting? The cable route for underground HV cables if often marked by warning tape and protected by a layer of tiles to minimise the risk of accidental excavation.

[WotEver]

Perhaps he meant tiling rather than ducting? The cable route for underground HV cables if often marked by warning tape and protected by a layer of tiles to minimise the risk of accidental excavation.

Indeed it is. It's also usually coaxial if it isn't SWA.

[WotEver]

NO excavation should be undertaken without clearing the area with a CAT or similar (cable location tool).

Very true: http://www.hse.gov.uk/electricity/information/excavations.htm

 

"Remember: Locators should be used frequently and repeatedly during the course of the work."

11kV ??

It was actually 11MV

... a 11000kva underground cable.

Made me smile too.

Edited October 4, 2016 by WotEver

[Batavia]

No idea, why don't you ask them which part of the 17th Regs they were referring to? Cable surrounded by soil isn't going to be any less warm than cable inside ducting inside soil, plus it has no mechanical protection.

 

Tony

Yes it will be! The current rating (for the same temperature rise) for direct buried cables is significantly higher than for cables in ducts, due to the improved heat transfer when the cable is in direct contact with the soil.

 

Chris G

[WotEver]

Yes it will be! The current rating (for the same temperature rise) for direct buried cables is significantly higher than for cables in ducts, due to the improved heat transfer when the cable is in direct contact with the soil.

Then the answer as to why he was told to change it was that he hadn't derated the cable for the chosen installation method.

 

Tony

Edited October 4, 2016 by WotEver

[Paul C]

Putting to one side burying cables in a couple of feet of soil (which would make for a dreadfully inefficient use of space on a narrowboat, and might well sink it too), its a pretty non-complicated area. However there's 2 factors:

 

1) A cables "maximum current rating" is probably rated in ideal conditions of it on its own (ie not in a bundle) in free air. If its bundled with other cables, not in free air ie in enclosed trunking, within insulation, etc, then there is a simple derating factor which can be applied.

 

2) There are other considerations in addition to max. current carrying capacity, to determine the thickness of a cable. Namely, voltage drop, mechanical strength and suitability. On a 12V (and dare I say it, 24V too) system I bet 8.999 times out of 10 the voltage drop determines the cable thickness; and the other 1/10 cases it will be mechanical strength, because they're cables carrying minute currents.