What size mains cable is your boat wired in?

[davidpbo]

I am considering putting some mains sockets on my boat and wonder what gauge cable others are wired in. Knowledge and experience tells me it should be 2.5mm but..... It is 24ft trailerable sailing boat with only occassional access to power via 16A outlets.

I intend to put on 2 double sockets and a single.
Single to do fan heater or battery charger.
Double 1 occasional kettle use (small travel type)
Double 2 chart table charging phones etc. and occasionally cool box.

Cable runs on the boat are minimal at 3m, 2m and 5m.
Run to boat say 20m.

I would like to keep weight and size down. I know 1.5 or 2.5 is rated for the current but that voltage drop is an issue with the 1.5.

What is used on your boat?

There will be a fuse box with isolator switch, RCCD and overcurrent protection.

 

[Aurai]

Your boat will not notice the weight difference 1.5/2.5 mm. After that, your circuit actual design will determine your cable requirements and your MCB rating. 2.5 mm and a 16A type B MCB is a common single item design for items like immersion heaters I believe. You are supposing three sockets and so you may run into what are called "discrimination" challenges and you still have to meet 0.4s disconnection times. All pointing you in the direction of 2.5mm, run your sketch past an electrician would be my best suggestion.

 

[VicS]

I am considering putting some mains sockets on my boat and wonder what gauge cable others are wired in. Knowledge and experience tells me it should be 2.5mm but..... It is 24ft trailerable sailing boat with only occassional access to power via 16A outlets.

I intend to put on 2 double sockets and a single.
Single to do fan heater or battery charger.
Double 1 occasional kettle use (small travel type)
Double 2 chart table charging phones etc. and occasionally cool box.

Cable runs on the boat are minimal at 3m, 2m and 5m.
Run to boat say 20m.

I would like to keep weight and size down. I know 1.5 or 2.5 is rated for the current but that voltage drop is an issue with the 1.5.

What is used on your boat?

There will be a fuse box with isolator switch, RCCD and overcurrent protection.

Voltage drop will not be an issue with 230 volt applications.

When you only have 12 volts available loss of one or two volts will be significant but when you hve 230 of them its not a problem. All you need worry about is the maximum safe current carrying capacity for the internal wiring

2.5mm is usually prefered for robustness for the shorepower cable even though the volts drop in a 20m run of 1.5 mm² at 16 amps is within acceptable limits.

 

[Lon nan Gruagach]

At 24ft you dont really need to consider location of the sockets so, for me, it would make sense to place them adjacent to the incoming management (shore cable termination, circuit breaker etc).
You might also consider a 240Vac to 12Vdc converter hard wired via a fused switched spur for the chart table stuff.
This would leave you with a double socket so close to the breaker that voltage drop and cable weight are both insignificant and another circuit that is inherently limited to a few amps (although the cabling to it must suit the upstream breaker).

That just leaves the occasional cool box....

 

[davidpbo]

Breakers will probably be in the (Dry) heads under a shelf as that is the most convenient location. It is no big deal to put in a few sockets in convenient locations to minimise loose cable hazards in a limited space.

 

[GrahamM376]

Location of breakers doesn't matter too much but the RCD should be as close to the incoming supply as possible. Ours is wired in 2.5mm spurs, not a ring circuit.

 

[VicS]

Location of breakers doesn't matter too much but the RCD should be as close to the incoming supply as possible. Ours is wired in 2.5mm spurs, not a ring circuit.

The requirement is for a manually reset, trip-free circuit breaker to be installed within 0.5m of the source of power, or if this is impractical the conductor from the source of power to the panel circuit breaker shall be contained in protective covering or a conduit or cable trunking. If 3m is exceed an additional circuit breaker within 3m of the input connection shall be provided.

I guess by 2.5mm spurs you mean as a radial circuit.

Anyone installing a 230 volt system on board should get hold of a copy of the latest edition ( 2014 ) of ISO 13297. The standard for alternating current systems in small craft.

 

[jimmyk]

I used an old (although excellent condition) shore power cable to wire my boat. I bought a garage rcd with two breakers and put the wire inside plastic conduit where it ran through the bilge bulkheads etc

 

[prv]

You might also consider a 240Vac to 12Vdc converter hard wired via a fused switched spur for the chart table stuff.

Surely any 12v kit will be running off the battery system.

Pete

 

[jimmyk]

Surely any 12v kit will be running off the battery system.

Pete

I got sockets with usb sockets in too. just to charge stuff while on shore power. they are so cheap now I though I might as well

 

[prv]

I got sockets with usb sockets in too. just to charge stuff while on shore power. they are so cheap now I though I might as well

Might as well if you were fitting 240v sockets anyway, I suppose, but it seems sub-optimal to me to have some USB sockets that work all the time and some that only work when you're in a marina, and have to ensure that your stuff is plugged into the right one.

I have four USB sockets over the "trash tray" near the chart table where portable electronics tend to congregate, plus one by each bunk for charging phones overnight. They work all the time (or rather, whenever the relevant switch on the main panel is on); if we're on shore power then their negligible drain will be topped up by the battery charger.

To answer the OP, Ariam is mostly wired with 2.5mm² cable but the runs to the battery charger and possibly the immersion heater (can't remember) are 1.5mm² since their power requirements are relatively low. But without doing the sums I suspect 1.5mm² is probably ok in a small simple boat.

Pete

 

[Lon nan Gruagach]

Surely any 12v kit will be running off the battery system.

Pete

Good point, with 12V topped up by battery charger. I think what threw me was the optional connection for the charger (something that I would put on a fused switched spur)

 

[GrahamM376]

I guess by 2.5mm spurs you mean as a radial circuit.
Anyone installing a 230 volt system on board should get hold of a copy of the latest edition ( 2014 ) of ISO 13297. The standard for alternating current systems in small craft.

Yes radial. The current regs are fine for new installations but my boat is 1988 and didn't even have an rcd when I bought it. I doubt many owners upgrade/rewire every time a new edition is published. Rightly or wrongly, I take the view that if it's safe, stuff the regulations unless coding the boat. One particular point I consider dangerous and have sometimes found is when additions have been made using identical cable in appearance to the low voltage loom. Mains circuit cables should be easily identifiable.

 

[davidpbo]

I used an old (although excellent condition) shore power cable to wire my boat. I bought a garage rcd with two breakers and put the wire inside plastic conduit where it ran through the bilge bulkheads etc

Only passing through ply partial partitions under bunks with either Artic or HO7R cable. Will use additional mechanical protection as necessary.

The requirement is for a manually reset, trip-free circuit breaker to be installed within 0.5m of the source of power, or if this is impractical the conductor from the source of power to the panel circuit breaker shall be contained in protective covering or a conduit or cable trunking. If 3m is exceed an additional circuit breaker within 3m of the input connection shall be provided.

I guess by 2.5mm spurs you mean as a radial circuit.

Anyone installing a 230 volt system on board should get hold of a copy of the latest edition ( 2014 ) of ISO 13297. The standard for alternating current systems in small craft.

Yes, radial, sorry for the in-exactitude.

Thanks as always for your input Vic. I have only been able to find a free download of what I believe is a 2000 version of ISO 13297 here

Can someone confirm that "Trip Free" RCCD means one that should not be trip due to removal or interruption of the incoming power as per common domestic 2 pole RCCDs. I intend to use a 10ma (2 Pole) trip (Which I have) if is No Trip although that might change in the event of excessive non fault tripping and yes Vic it is the one I purchased off ebay some time ago and will have appropriate over current protection as well! . It is worth people noting that many RCBOs (Combined RCBS and (Overcurrent) Circuit breakers particularly the single width ones ( I believe) only break the live connection despite having live and neutral connected to them.

Surely any 12v kit will be running off the battery system.

Pete

It will at present I have not decided what to do regarding a battery charger. Currently a 10W solar panel and some charging from the outboard has sufficed on Windermere. Now there is some access to power I keep and cheap constant voltage charger on board just in case and have a more sophisticated Halfords portable charger at home similar to this

I got sockets with usb sockets in too. just to charge stuff while on shore power. they are so cheap now I though I might as well

Might as well if you were fitting 240v sockets anyway, I suppose, but it seems sub-optimal to me to have some USB sockets that work all the time and some that only work when you're in a marina, and have to ensure that your stuff is plugged into the right one.

I have four USB sockets over the "trash tray" near the chart table where portable electronics tend to congregate, plus one by each bunk for charging phones overnight. They work all the time (or rather, whenever the relevant switch on the main panel is on); if we're on shore power then their negligible drain will be topped up by the battery charger.

To answer the OP, Ariam is mostly wired with 2.5mm² cable but the runs to the battery charger and possibly the immersion heater (can't remember) are 1.5mm² since their power requirements are relatively low. But without doing the sums I suspect 1.5mm² is probably ok in a small simple boat.

Pete

Might consider that if I can get a decent brand like MK. Getting very wary of cheap as chips wall wart chargers and the like now, although I have not had any problems so far.

Good point, with 12V topped up by battery charger. I think what threw me was the optional connection for the charger (something that I would put on a fused switched spur)

It is not at present as I don't have what I regard as an appropriate charger for permanent connection and don't want to incur excessive expense. If anyone can recommend a suitable relatively cheap permanent charger I will consider it.

Yes radial. The current regs are fine for new installations but my boat is 1988 and didn't even have an rcd when I bought it. I doubt many owners upgrade/rewire every time a new edition is published. Rightly or wrongly, I take the view that if it's safe, stuff the regulations unless coding the boat. One particular point I consider dangerous and have sometimes found is when additions have been made using identical cable in appearance to the low voltage loom. Mains circuit cables should be easily identifiable.

Agree with that. I sometimes work on ships (Not primarily on the mains) and the wiring colour codes there can be interesting depending on where they have been refitted and what low voltage (110 or 240V ish) mains you are dealing with.

 

[VicS]

Only passing through ply partial partitions under bunks with either Artic or HO7R cable. Will use additional mechanical protection as necessary.



Yes, radial, sorry for the in-exactitude.

Thanks as always for your input Vic. I have only been able to find a free download of what I believe is a 2000 version of ISO 13297 here

Can someone confirm that "Trip Free" RCCD means one that should not be trip due to removal or interruption of the incoming power as per common domestic 2 pole RCCDs. I intend to use a 10ma (2 Pole) trip (Which I have) if is No Trip although that might change in the event of excessive non fault tripping and yes Vic it is the one I purchased off ebay some time ago and will have appropriate over current protection as well! . It is worth people noting that many RCBOs (Combined RCBS and (Overcurrent) Circuit breakers particularly the single width ones ( I believe) only break the live connection despite having live and neutral connected to them.



It will at present I have not decided what to do regarding a battery charger. Currently a 10W solar panel and some charging from the outboard has sufficed on Windermere. Now there is some access to power I keep and cheap constant voltage charger on board just in case and have a more sophisticated Halfords portable charger at home similar to this






Might consider that if I can get a decent brand like MK. Getting very wary of cheap as chips wall wart chargers and the like now, although I have not had any problems so far.



It is not at present as I don't have what I regard as an appropriate charger for permanent connection and don't want to incur excessive expense. If anyone can recommend a suitable relatively cheap permanent charger I will consider it.



Agree with that. I sometimes work on ships (Not primarily on the mains) and the wiring colour codes there can be interesting depending on where they have been refitted and what low voltage (110 or 240V ish) mains you are dealing with.

Yes I think the only version of the ISO 13297 which you will find available free on line is the 2000 or 2001 edition. I managed to down load the 2012 version while it was briefly available on a Bulgarian website. One day I am going to ask if the public library can get the 2014 edition as I don't expect to find that as free download anytime soon.


A "trip-free" circuit breaker is one which cannot be prevented from tripping by holding ( jamming with a matchstick etc) the ON/reset button.

 

[JumbleDuck]

Yes radial. The current regs are fine for new installations but my boat is 1988 and didn't even have an rcd when I bought it. I doubt many owners upgrade/rewire every time a new edition is published. Rightly or wrongly, I take the view that if it's safe, stuff the regulations unless coding the boat.

Indeed. It is also arguably over the top to try to apply regulations drawn up for everything up to stuffing great motor boats to a small sailing boat with a very basic mains electrical system. If you want seamless transfer of 12V and 240 between shore, battery and engine power through chargers and inverters then yes, the standards are probably worth a look, but for a mains hookup and three sockets? Meh.

My own boat has a 16A connection the the cockpit to a double socket with inbuilt RCD in the cabin. I have no idea whether that meets ISO's current notion of how a superyacht should be wired, but it doesn't bother me. Mind you, I'm going to take it all out this winter. The 16A cable is a pain to store so for the last couple of years I have been using a standard wind-up extension lead with a 16A plug on the end. That would probably upset ISO as well.

 

[davidpbo]

Indeed. It is also arguably over the top to try to apply regulations drawn up for everything up to stuffing great motor boats to a small sailing boat with a very basic mains electrical system. If you want seamless transfer of 12V and 240 between shore, battery and engine power through chargers and inverters then yes, the standards are probably worth a look, but for a mains hookup and three sockets? Meh.

My own boat has a 16A connection the the cockpit to a double socket with inbuilt RCD in the cabin. I have no idea whether that meets ISO's current notion of how a superyacht should be wired, but it doesn't bother me. Mind you, I'm going to take it all out this winter. The 16A cable is a pain to store so for the last couple of years I have been using a standard wind-up extension lead with a 16A plug on the end. That would probably upset ISO as well.

I agree, what I want to achieve with safety is basically equivalent to a modified multigang socket with sockets distributed to a limited degree around a small area of the cabin <2m by 2m with sensible protection. From what I have read so far, what I propose will probably abide pretty closely to the requirements anyway.

Am I right in assuming the people who write the standards are not getting their income by their sale?
If that is the case my view is that if the society/government want things done to "Standards/Regulations" then those standards or regulations should be readily and freely available to download.

 

[Halo]

The main trick is to get folks used to only plugging in one heavy current user at a time. e.g heater, kettle, toaster, microwave, hair dryer

The main hazard with shore power is not the internal wiring - it is the slip hazard of treading on a round cable which can act like a roller under your feet. Have a shore lead long enough to go on the side away from the pontoon.

 

[[163233]]

To answer the OP, Ariam is mostly wired with 2.5mm² cable...

Thinking of redoing mine, as it's lacking an RCD completely. Is heavy flex rather than that stiff house cable considered good or bad?

 

[VicS]

Thinking of redoing mine, as it's lacking an RCD completely. Is heavy flex rather than that stiff house cable considered good or bad?

You should use flexible 3 core cable , not the solid conductor T&E cable used for house wiring.