Shore power cable size

[sealegsjim]

I am about to buy a shore power cable for my new boat. Screwfix have have two 14m cables both rated at 16amp and the same end fittings. One is 1.5mm and the other is 2.5mm. Is there any disadvantage in the 1.5mm which is obviously lighter and easier to handle/store and incidently, cheaper. The marina supply is 17amp. Thanks

 

[VicS]

I am about to buy a shore power cable for my new boat. Screwfix have have two 14m cables both rated at 16amp and the same end fittings. One is 1.5mm and the other is 2.5mm. Is there any disadvantage in the 1.5mm which is obviously lighter and easier to handle/store and incidently, cheaper. The marina supply is 17amp. Thanks

physical robustness would be the reason to opt for the heavier cable but if handling and storage are issues go for the lighter one.

I take it these are arctic grade, usually chosen for its flexibility at low temperatures. If not buy (blue) arctic grade and fit your own connectors

 

[sailorman]

I am about to buy a shore power cable for my new boat. Screwfix have have two 14m cables both rated at 16amp and the same end fittings. One is 1.5mm and the other is 2.5mm. Is there any disadvantage in the 1.5mm which is obviously lighter and easier to handle/store and incidently, cheaper. The marina supply is 17amp. Thanks

2.5mm is what you want

 

[sealegsjim]

physical robustness would be the reason to opt for the heavier cable but if handling and storage are issues go for the lighter one.

I take it these are arctic grade, usually chosen for its flexibility at low temperatures. If not buy (blue) arctic grade and fit your own connectors

Thanks VicS for your speedy reply. I was hoping it was just a case of durability. Both cables are arctic grade.

 

[VicS]

After thought

2.5mm cable is rated at 25 amps .... It would be a better choice if you wanted to run close to the 16 amp mark without fully uncoiling it

 

[prv]

I worked out the volt drop on mine, assuming I'm pulling the full 16 amps, and decided I needed 2.5mm².

1.5 might be ok if you only ever plug into a socket adjacent to your marina finger with a short cable, but I have 4 x 10m lengths in case I need to reach further away. Two in the cockpit locker for ready use, two in deep storage for those rare occasions. Multiple shorter lengths are easier to manage than one long one, and neater when the socket is close by.

Pete

 

[colind3782]

I worked out the volt drop on mine, assuming I'm pulling the full 16 amps, and decided I needed 2.5mm².

1.5 might be ok if you only ever plug into a socket adjacent to your marina finger with a short cable, but I have 4 x 10m lengths in case I need to reach further away. Two in the cockpit locker for ready use, two in deep storage for those rare occasions. Multiple shorter lengths are easier to manage than one long one, and neater when the socket is close by.

Pete

+1. Go for 2.5mm. One berth I had for a short time necessitated a cable run of nearly 70m! You could almost count the electrons dribbling out of the end.

 

[sealegsjim]

+1. Go for 2.5mm. One berth I had for a short time necessitated a cable run of nearly 70m! You could almost count the electrons dribbling out of the end.

I am in a marina on Windermere and my cable run will never be longer than about 10m so I think I will go for the 1.5mm. Thanks for your reply

 

[Bru]

Definitely 2.5mm. No two ways about it

 

[NormanS]

It depends on what you want to do with it. If all you want is a light, the thinner one will do, but if you will be using it for heat, you need the thicker cable.

 

[VicS]

I am in a marina on Windermere and my cable run will never be longer than about 10m so I think I will go for the 1.5mm. Thanks for your reply

So that you can make an informed decision a few simple calculations show that the volts drop over 14m (that's 28m total live +neutral) 1.5mm²cable at the full 15amps will be approx 5volts.

Proportionally less for smaller currents, proportionally more for longer cables


The volts drop on 14m of 2.5mm²cable at 15amps will be approx 3volts.

 

[sealegsjim]

Thanks to everyone for your (as ever) informed replies. I took your collective advice and bought the 2.5mm

 

[Bru]

Thanks to everyone for your (as ever) informed replies. I took your collective advice and bought the 2.5mm

Good God in heaven above! You're not supposed to do THAT! The proper form is to totally ignore all the advice, move the goalposts by alterering the original question and then you buy the thing that YOU wanted to buy in the first place despite everybody saying you shouldn't.

Any more of this my lad and we'll have to send Mr. Winter round to reorientate you!

 

[David2452]

2.5mm2 is absolutely what you should have bought, however H07 is far nicer than Arctic, easier to coil, better UV resistance and more abrasion resistant. Arctic is cheaper and easier to get, that's why you see so much of it used for shore power cables.

 

[sailorman]

Good God in heaven above! You're not supposed to do THAT! The proper form is to totally ignore all the advice, move the goalposts by alterering the original question and then you buy the thing that YOU wanted to buy in the first place despite everybody saying you shouldn't.

Any more of this my lad and we'll have to send Mr. Winter round to reorientate you!

Wych one

 

[Bru]

2.5mm2 is absolutely what you should have bought, however H07 is far nicer than Arctic, easier to coil, better UV resistance and more abrasion resistant. Arctic is cheaper and easier to get, that's why you see so much of it used for shore power cables.

Agreed, we used to use HO7 in preference to Arctic on our 16A distro around festival stage for all the reasons you state plus we could get HO7 in black (bright blues and oranges tend to stand out a bit!). If I was making up cables from scratch I'd prefer HO7 but Arctic is what is readily available retail and it does the job well enough for most people

 

[VicS]

Good God in heaven above! You're not supposed to do THAT! The proper form is to totally ignore all the advice, move the goalposts by alterering the original question and then you buy the thing that YOU wanted to buy in the first place despite everybody saying you shouldn't.

Any more of this my lad and we'll have to send Mr. Winter round to reorientate you!

Or buy the orange garden stuff that goes absolutely rigid rigid below about 60F.

 

[GHA]

, however H07 is far nicer than Arctic, easier to coil, better UV resistance and more abrasion resistant.

+1
It's the norm for live event light cable etc, will withstand a ridiculous amount of abuse. Easier to stow without a drum as well.

 

[Bru]

+1
It's the norm for live event light cable etc, will withstand a ridiculous amount of abuse. Easier to stow without a drum as well.

23p a metre more expensive plus the dreaded from Essential for 2.5mm HO7. Not a vast difference in the overall scheme of things

Trouble is the mainstream suppliers for shore power cables and caravan site power cables are all hooked on arctic

 

[Boathook]

2.5mm is what you want

I have 4mm for the winter with the 16amp sockets in an attempt to remove voltage drop at 16 amps over 40 metres cable length. Summer cables are 2.5mm and somewhat shorter !