Wiring diagrams

[ChrisL]

I'm sure that this has been asked before. I'm new to narrowboats and currently considering a sail away, well I'm almost at the point of saying yes after exploring some of the pit falls I might have, I'm sure mistakes will be made

I feel confident over most of the fitout but the one area I have concern is getting the wiring correct as this could destroy he hull if I get things wrong

My experience I'm a mechanical engineer but I have a reasonable understanding of electrics, House electrics I understand and am very confident with (rewired many a house but had it Checked/certified afterwards), car electrics which is possibly similar to a narrowboat again I'm confident with, I've made numerous full car looms for my cars and for friends. 

What I would like to see is some diagrams for a typical narrowboat so I can start and do 1st fix

I have seen on here some people have offered drawings but I cant reach out until I've done my 10 posts so hopefully someone or a few will make contact to assist.

I know this is not going to be easy but hopefully with the help and knowledge of others I can master this task

thanks in advance Chris

[David Mack]

8 minutes ago, ChrisL said:

car electrics which is possibly similar to a narrowboat

No. Car electrics use the bodywork as the negative return. On a boat you must not do this - you need to run separate negative wires back to the fuseboard/battery. 

[ChrisL]

David thanks, yes I understood that, the car statement was just to help others see what abilities I have, or not as I'm sure ill get shot down

I'm up to 2 posts now 

Edited February 4, 2023 by ChrisL

[Jen-in-Wellies]

Welcome to the forum.

Your experience with household and car wiring will take you most of the way there. Things to think of with a typical inland waterways boat.

They are usually much longer than a car. For 12V cable sizes, voltage drop is typically more important than current carrying capacity for selection. Typically, to get a reasonable voltage at the other end of the boat you will need a much bigger square millimeter cable area than you'd first suspect. There are voltage drop calculators around online for this. Some boats are wired 24V, rather than 12V for this reason, but 24V gadgets are less common and sometimes more expensive than 12V.

For mains and 12V wirng, multistrand cable. Lots of vibration on a boat and multistrand is more resistant to breakage from vibration than single strand. This means no twin core and earth for mains, but "Arctic" multistrand cable. Ferrules on cable ends when using screw connectors. Crimp connections, rather than solder.

Earthing to the hull at one point only for 12V and a seperate, but close point for mains. No using the hull as a return path, but a return wire for each circuit. The doubled wire length needs to be included in voltage drop calculations and makes cable size even bigger for acceptable voltage drop. This is to prevent stray currents through the hull and galvanic corrosion. Similarly, if you intend to install a shore lead connection to a bollard, then you need to separate grid earth from boat earth, using a galvanic isolator, or isolation transformer. The two can be at slightly different voltages that can again set up a local corrosion cell between the boat hull and shore structures, or other boats. Lots of posts on here about this.

There are specific ISO specifications for boat wiring that @Alan de Enfield will be along to quote you. These need following for Recreational Craft Directive (or whatever its post Brexit name now is) compliance and are good practice anyway. There are also boat safety scheme requirements on cable sizing, physical protection, fusing, battery location, hold down, connection and so on that will need following. Most 12V goes through an isolator switch from the battery. Almost all things go through a fuse too (exceptions around starter motors, alternators). Fuse size to protect the wiring, not the appliance at the end. Breakers and residual current protection on mains. All happy fun reading before you start cutting cable and laying it through the boat.

Wiring diagrams are actually pretty simple. Most of it is the same simple circuit over and over again. There is a copy of my boat's on the forum somewhere.

 

Jen

Edited February 5, 2023 by Jen-in-Wellies

[MtB]

58 minutes ago, ChrisL said:

What I would like to see is some diagrams for a typical narrowboat so I can start and do 1st fix

 

Diagrams rarely give cable cross sectional areas, and as Jen explained but it is worth repeating, the cable CSA is crucial to minimise voltage drops when carrying current.

 

The sheer size of cables needed might shock you given the experience you've had so far. The cable runs of just a few metres each way to a 12v fridge for example, often work out to require 10mm2 CSA or even larger.

 

Start by researching Volt drops rather than looking at circuit diagrams. 

 

Also, I sggest using a domestic consumer unit with DC-rated MCBs rather than one of the commonly sold and feebly constructed 'marine' distribution/fuse boards. Any fuseboard using crimp connectors is usually a disaster once you find yourself trying to connect 6mm and bigger cables with crimp terminals. 

[ChrisL]

7 hours ago, Jen-in-Wellies said:

Welcome to the forum.

Your experience with household and car wiring will take you most of the way there. Things to think of with a typical inland waterways boat.

They are usually much longer than a car. For 12V cable sizes, voltage drop is typically more important than current carrying capacity for selection. Typically, to get a reasonable voltage at the other end of the boat you will need a much bigger square millimeter cable area than you'd first suspect. There are voltage drop calculators around online for this. Some boats are wired 24V, rather than 12V for this reason, but 24V gadgets are less common and sometimes more expensive than 12V.

For mains and 12V wirng, multistrand cable. Lots of vibration on a boat and multistrand is more resistant to breakage from vibration than single strand. This means no twin core and earth for mains, but "Arctic" multistrand cable. Ferrules on cable ends when using screw connectors. Crimp connections, rather than solder.

Earthing to the hull at one point only for 12V and a seperate, but close point for mains. No using the hull as a return path, but a return wire for each circuit. The doubled wire length needs to be included in voltage drop calculations and makes cable size even bigger for acceptable voltage drop. This is to prevent stray currents through the hull and galvanic corrosion. Similarly, if you intend to install a shore lead connection to a bollard, then you need to separate grid earth from boat earth, using a galvanic isolator, or isolation transformer. The two can be at slightly different voltages that can again set up a local corrosion cell between the boat hull and shore structures, or other boats. Lots of posts on here about this.

There are specific ISO specifications for boat wiring that @Alan de Enfield will be along to quote you. These need following for Recreational Craft Directive (or whatever its post Brexit name now is) compliance and are good practice anyway. There are also boat safety scheme requirements on cable sizing, physical protection, fusing, battery location, hold down, connection and so on that will need following. Most 12V goes through an isolator switch from the battery. Almost all things go through a fuse too (exceptions around starter motors, alternators). Fuse size to protect the wiring, not the appliance at the end. Breakers and residual current protection on mains. All happy fun reading before you start cutting cable and laying it through the boat.

Wiring diagrams are actually pretty simple. Most of it is the same simple circuit over and over again. There is a copy of my boat's on the forum somewhere.

 

Jen

Jen first off many thanks for taking the time to make such a great reply, that has given me me confidence in my thoughts so far. I have read many items such as Graham mills posts which breakdown each area. Yes voltage drop was one of the areas that jumped out (concern) to me as it seemed the one size (like a house) approach for circuits doesn't work. I hadn't picked up on double length  for voltage from so pleased I asked the question. I am up to speed about types of cable but again yesterday only did I realise I should only use Artic blue not yellow. I have read about Wago connector blocks so I'm not 100% sure if these should be used both on 12v and or 240v circuits or should I feed in and out of each item on the circuit. My thoughts is to feed along the gunnels my circuit then use these

to take a feed off for my each item, this way I can then adapt if I need to change around in the future if say we wanted to modify the layout.

I'm aware that 240v needs to be run in separate duct from 12v but I cant find if there is any separation distance for these, my thoughts are to use flexible corrugated ducting clipped to gunnels every 300mm or would the white clip in be a more sensible option as the corrugated will be a series of sections as I T out, advise on this area would be gratefully appreciated

Any recommendation on 12v isolation/indicator board (possibly another name for it) that people have or is it best just to make up your own getting the plate engraved, if so any particular manufacture specific items that might recommend for this

I'll have a dig around for your diagrams, I have seen some from 12volt boating group which was recommended on FB

thanks again for your response

 

[ChrisL]

7 hours ago, MtB said:

 

Diagrams rarely give cable cross sectional areas, and as Jen explained but it is worth repeating, the cable CSA is crucial to minimise voltage drops when carrying current.

 

The sheer size of cables needed might shock you given the experience you've had so far. The cable runs of just a few metres each way to a 12v fridge for example, often work out to require 10mm2 CSA or even larger.

 

Start by researching Volt drops rather than looking at circuit diagrams. 

 

Also, I sggest using a domestic consumer unit with DC-rated MCBs rather than one of the commonly sold and feebly constructed 'marine' distribution/fuse boards. Any fuseboard using crimp connectors is usually a disaster once you find yourself trying to connect 6mm and bigger cables with crimp terminals. 

MtB thanks for your reply yes cross section was a concern as I was wondering if I had it right with feeding all those into ductwork at gunnels and cramming these in 

domestic consumer unit interesting thought I'll look at that so you are saying use MCB's but DC ones in the domestic box I didn't realise you could get those 

you mention crimp ends in fuse board is a disaster but do you recommend crimp ends for termination into sockets as we move through the boat

as you can see I'm learning maybe slowly but I like to plan rather than jump in as we all know there will be mistakes on the journey so the more I overcome the better 

thanks again

[Tony Brooks]

16 minutes ago, ChrisL said:

My thoughts is to feed along the gunnels my circuit then use these to take a feed off for my each item,

 

Remember that you need fuses/circuit breakers to protect the cable. Your cables running along the gunnels will be thick to carry sufficient current for all the items you connect to it, so it will need a higher current fuse.  The cables that you "tap off" the large cables will either need to be the same size, so the fuses will blow before they catch fire or, more likely, they will be large enough for just the few items connected to it. That means it needs its own fuse that is rated for the cable size.  It follows that if you adopt this scheme that you will have fuses/circuit breakers placed at random intervals along the gunnels. That may be fine for you because you will know where each fuse is located, but if anyone else needs to fault find, it may be a nightmare. It is for good reason that by and large the domestic 12/24V circuits are wired back to just one fuse box close to the batteries, where all the fuses/circuit breakers are located. I understand, but have not seen, that some fit out a pair of large cables running up the boat, but then locate two or three fuse boxes, front, back and centre. Basically, boats tend to be wired like house radial power circuits.

 

 

[Jen-in-Wellies]

As you plan to fit out your boat, then having accessible cable ducting at gunwhale level is a good idea for the reasons you give, but other wiring, for example to ceiling down lighters, will not be accessible once the lining is fixed in place, so access isn't as useful as you'd at first think. Wagos for 12V is fine, as long as they are within wire size and current carrying capacity for the circuit. The circuits they are most likely to be used on is for lighting, where parallel switches and multiple LED lamps are being fed from a single circuit. Being LED, the currents are low.

@MtB 's comments about crimp terminals and "marine" fuse/breaker boards are to do with large (6mm2 plus) cables. In general, crimp terminals are the way to go. My practice with this type of fuse/breaker board was to take the thick, 25mm2 cable to a bus bar, then feed each breaker with an appropriate size cable from that. The boards are supplied with a daisy chain connection of too small gauge wire, which will easily get overloaded and I throw that out. Using a consumer unit and 12V breakers is a neat way of avoiding these problems and I'd seriously consider it for another boat.

Jen

24 minutes ago, ChrisL said:

Any recommendation on 12v isolation/indicator board (possibly another name for it) that people have or is it best just to make up your own getting the plate engraved, if so any particular manufacture specific items that might recommend for this

I've done this for friends on a number of occasions. Most cities will have a place that makes instrument panels that will produce something from a drawing for a reasonable fee. Can have the boat name and gives a shiny professional look. The typical canal boat ones you can buy, link above, are cheap and nasty looking, though the lumpy water boaters have some better looking ones in their market, at a cost.

 

[Tracy D'arth]

Can I recommend     https://shop.waterwaysworld.com/product/NBBUILDERS/the-narrowboat-builder-s-book  as a good handbook to wiring and general fitting out?

 

Schneider circuit breakers are approved for DC and AC and are less expensive than the dedicated DC ones.  A large domestic consumer unit with separate radial circuits to a group of lights, say port side,  to sockets, water pump, shower drain pump etc. is the way to go. Then you can accommodate decent sized wire in the terminals, the ready made marine panels are horrible, a mess of crimp connectors and thin cables.

It does not have to be Artic cable, no specific sheath colour, but must be fine stranded flex cable. 

The 12v circuits are best wired in single cable you will find, using 3 core for 240V. There are certain colours to be used on the 12v but it is not rigidly enforced. Foe example I use yellow for 12v positives and black for negatives. All mains wiring should be brown/blue/green-yellow.

Edited February 5, 2023 by Tracy D'arth

[Tony Brooks]

5 minutes ago, Jen-in-Wellies said:

but other wiring, for example to ceiling down lighters, will not be accessible once the lining is fixed in place, so access isn't as useful as you'd at first think

 

This is why some boats have ducting under removable panels in the roof. They may be down the centre or one on each side. Using a right angle trim section between roof and cabin side provides another opportunity to fit accessible ducting. 

 

PS the electrical course notes on my website might help you see address in my signature

Edited February 5, 2023 by Tony Brooks

[ChrisL]

3 minutes ago, Tracy D'arth said:

Can I recommend     https://shop.waterwaysworld.com/product/NBBUILDERS/the-narrowboat-builder-s-book  as a good handbook to wiring and general fitting out?

Tracy thanks for the link strongly I ordered that last night so good to get a recommendation for it

 

[Jen-in-Wellies]

8 minutes ago, Tony Brooks said:

This is why some boats have ducting under removable panels in the roof. They may be down the centre or one on each side. Using a right angle trim section between roof and cabin side provides another opportunity to fit accessible ducting. 

This is a good idea. I helped a friend rewire a boat with this style of ducting and it made the ceiling lights much easier to work on. We incorporated the light switches in to the ceiling too, which is great if you are tall enough to reach them, which she is.

10 minutes ago, Tracy D'arth said:

Can I recommend     https://shop.waterwaysworld.com/product/NBBUILDERS/the-narrowboat-builder-s-book  as a good handbook to wiring and general fitting out?

Another recommendation for this book. Also the related narrowboat designer book by the same author. Both getting rather dated now, but the general principals remain true.

Jen

[ChrisL]

10 minutes ago, Jen-in-Wellies said:

As you plan to fit out your boat, then having accessible cable ducting at gunwhale level is a good idea for the reasons you give, but other wiring, for example to ceiling down lighters, will not be accessible once the lining is fixed in place, so access isn't as useful as you'd at first think. Wagos for 12V is fine, as long as they are within wire size and current carrying capacity for the circuit. The circuits they are most likely to be used on is for lighting, where parallel switches and multiple LED lamps are being fed from a single circuit. Being LED, the currents are low.

@MtB 's comments about crimp terminals and "marine" fuse/breaker boards are to do with large (6mm2 plus) cables. In general, crimp terminals are the way to go. My practice with this type of fuse/breaker board was to take the thick, 25mm2 cable to a bus bar, then feed each breaker with an appropriate size cable from that. The boards are supplied with a daisy chain connection of too small gauge wire, which will easily get overloaded and I throw that out. Using a consumer unit and 12V breakers is a neat way of avoiding these problems and I'd seriously consider it for another boat.

Jen

I've done this for friends on a number of occasions. Most cities will have a place that makes instrument panels that will produce something from a drawing for a reasonable fee. Can have the boat name and gives a shiny professional look. The typical canal boat ones you can buy, link above, are cheap and nasty looking, though the lumpy water boaters have some better looking ones in their market, at a cost.

 

Jen thanks again its helpful to get advice like this with little snippets of advice that sets me off searching for ideas, I had seen the use of busbars so will explore, I'm one of those people that looks at things and takes a photo so I can study items and what's around it, I find this method of learning what suits me. My intention with the build is to make panels up for the side cladding that will be secret fixed at top, I saw this at Steve Ellis boat fitters this allows the side panels to be removed if need be, hopefully I won't be doing on a regular basis but as I say I'm sure errors will occur on the way.

so that's 2 recommendation for a consumer unit

Hopefully with this community and other boaters in the marina we will be using I will be able to plan this, also I'm hoping I can pick up ideas and photograph some distribution boards and wiring methods at the NEC at Boatlife. 

[GUMPY]

All my lighting runs down two ceiling ducts one each side under where the "striplights" are. With the switches at gunwale level. All lighting is LED 

 

Edited February 5, 2023 by Loddon

[MtB]

Just to labour the point, here is a link to exactly the sort of fuse and switch panel to avoid. 

 

When you attach a load of 'fat enough' wires to the spade terminals on the back and try to push it into its final mounting position, the stiffness of fat wires bends the crimp terminals and they loosen or worse, fall off. The opposite happens when you try to remove it to get at the back. Half the wires fall off as you pull it out. Horrible things, best avoided.

https://www.midlandchandlers.co.uk/products/ag-12-way-circuit-breaker-switch-panel-vs-128

 

I've just binned an almost identical panel from one of my boats and fitted a decent household consumer unit to tidily replace it, populated with DC rated MCBs for this exact reason. I'll take a photo of it next time I visit the boat.

 

[ChrisL]

20 minutes ago, Tony Brooks said:

 

This is why some boats have ducting under removable panels in the roof. They may be down the centre or one on each side. Using a right angle trim section between roof and cabin side provides another opportunity to fit accessible ducting. 

Tony I had considered a centre roof duct but having removable side panel I feel should give me the access requirements I possibly will need 

[Higgs]

1 minute ago, MtB said:

Just to labour the point, here is a link to exactly the sort of fuse and switch panel to avoid. 

 

When you attach a load of 'fat enough' wires to the spade terminals on the back and try to push it into its final mounting position, the stiffness of fat wires bends the crimp terminals and they loosen or worse, fall off. The opposite happens when you try to remove it to get at the back. Half the wires fall off as you pull it out. Horrible things, best avoided.

 

https://www.midlandchandlers.co.uk/products/ag-12-way-circuit-breaker-switch-panel-vs-128

 

I've just binned an almost identical panel from one of my boats and fitted a decent household consumer unit to tidily replace it, populated with DC rated MCBs for this exact reason. I'll take a photo of it next time I visit the boat.

 

 

I also don't like the cheap compressed foam/plastic these units are made out of. They are more like the quality you'd expect in pound shops. 

 

 

[ChrisL]

8 minutes ago, Loddon said:

All my lighting runs down two ceiling ducts one each side under where the "striplights" are. With the switches at gunwale level. All lighting is LED 

 

Loddon that's a good thought for lighting circuits

 

[ChrisL]

5 minutes ago, MtB said:

Just to labour the point, here is a link to exactly the sort of fuse and switch panel to avoid. 

 

When you attach a load of 'fat enough' wires to the spade terminals on the back and try to push it into its final mounting position, the stiffness of fat wires bends the crimp terminals and they loosen or worse, fall off. The opposite happens when you try to remove it to get at the back. Half the wires fall off as you pull it out. Horrible things, best avoided.

https://www.midlandchandlers.co.uk/products/ag-12-way-circuit-breaker-switch-panel-vs-128

 

I've just binned an almost identical panel from one of my boats and fitted a decent household consumer unit to tidily replace it, populated with DC rated MCBs for this exact reason. I'll take a photo of it next time I visit the boat.

 

MtB thanks for this as I said above pictures say loads more to me, this helps, I'll explore photos, descriptions of distribution boards used in narrowboat applications, thanks for the offer of taking a photo

 

[Alan de Enfield]

Here is the ISO standard you need to work to :

 

 

ISO 13297:2020

Small craft — Electrical systems — Alternating and direct current installations

 

 

With regard to termination of cables there are specifications for the type of terminal, the pull off force of the terminal to the wire and the number of terminals per 'stud'.

 

Put aside anything you have learned about both Domestic and automotive wiring.

 

eg :

 

10 Wiring connections and terminals

10.1 Conductor connections shall be in locations protected from the weather or in IP 55 enclosures, in accordance with IEC 60529 as a minimum. Connections above deck exposed to intermittent immersion shall be in IP 67 enclosures, in accordance with IEC 60529 as a minimum.

10.2 Metals used for terminal studs, nuts and washers shall be corrosion resistant and galvanically compatible with the conductor and terminal. Aluminium and unplated steel shall not be used for studs, nuts or washers in electrical circuits.

10.3 All conductors shall have suitable terminals installed, i.e. no bare wires attached to stud or screw connections.

10.4 Screw-clamp or screwless terminal blocks shall conform to IEC 60947-7-1. Other terminals shall be of the ring or self-locking captive-spade type, not dependent on screw or nut tightness alone for retention on the stud or screw. An exception is that friction-type connectors may be used in circuits not exceeding 20 A if the connection does not separate when subjected to a force of 20 N. 10.5 Twist-on connectors (wire nuts) shall not be used.

 

 

 

 

 

 

 

[rusty69]

And never underestimate the power of bootlace ferrules 

[David Mack]

15 minutes ago, ChrisL said:

My intention with the build is to make panels up for the side cladding that will be secret fixed at top, I saw this at Steve Ellis boat fitters this allows the side panels to be removed if need be,

Just be aware that the window/porthole lining/trims usually used overlap the cabin lining, so need to be removed first before you can take down the lining panel. And the window frames/portholes themselves are often screwed through into the trims from the outside. So removing a cabin lining panel may not be straightforward.

There are other ways of doing it, but it all needs thinking about!

[ChrisL]

5 minutes ago, Alan de Enfield said:

Here is the ISO standard you need to work to :

 

 

ISO 13297:2020

Small craft — Electrical systems — Alternating and direct current installations

 

 

With regard to termination of cables there are specifications for the type of terminal, the pull off force of the terminal to the wire and the number of terminals per 'stud'.

 

Put aside anything you have learned about both Domestic and automotive wiring.

 

eg :

 

10 Wiring connections and terminals

10.1 Conductor connections shall be in locations protected from the weather or in IP 55 enclosures, in accordance with IEC 60529 as a minimum. Connections above deck exposed to intermittent immersion shall be in IP 67 enclosures, in accordance with IEC 60529 as a minimum.

10.2 Metals used for terminal studs, nuts and washers shall be corrosion resistant and galvanically compatible with the conductor and terminal. Aluminium and unplated steel shall not be used for studs, nuts or washers in electrical circuits.

10.3 All conductors shall have suitable terminals installed, i.e. no bare wires attached to stud or screw connections.

10.4 Screw-clamp or screwless terminal blocks shall conform to IEC 60947-7-1. Other terminals shall be of the ring or self-locking captive-spade type, not dependent on screw or nut tightness alone for retention on the stud or screw. An exception is that friction-type connectors may be used in circuits not exceeding 20 A if the connection does not separate when subjected to a force of 20 N. 10.5 Twist-on connectors (wire nuts) shall not be used.

 

 

 

 

 

 

 

Alan something to digest some good pointers for me thanks 

[MtB]

3 minutes ago, rusty69 said:

And never underestimate the power of bootlace ferrules 

 

And once you start using them, how near-impossible they make it to fit two wires into one terminal!

 

So difficult that there are special 'twin cable' bootlace ferrules too, which will turn out to be as essential to keep in stock as single-cable ferrules.