Replacement masthead light

[mrangry]

I have purchased an Aqua signal 34 masthead tri colour and anchor light to replace the old existing unit when the mast comes down next week. Whilst down I also intend to run a new tinned 3 core cable, but in a quandary over cable sizing for this job. The cable run from battery to masthead is around 26 metres, the lamp unit is rated at 1.5 watts and the boat`s dc voltage is 12v. I have had a search online but seem to be having a mental block on working this out.....any input appreciated.

 

[pvb]

Tinned 3-core cable is usually offered in a minimum size of 1.5mm², which would be more than adequate for your needs (it'd give a volt drop of only around 0.1v).

 

[PaulRainbow]

What he said ↑↑

 

[PaulRainbow]

If you need 26m, probably best to buy a 30m roll

1.5mm² 3 Core Tinned Thin Wall Electrical Cable

Edit: Posts below are correct Furneaux Riddall are cheaper.

1.5mm Marine Tinned 3 Core Thin Wall Cable - 30m

 

[rogerthebodger]

Buy your electrical cable from a local electrical factor should be much cheaper

 

[pvb]

Buy your electrical cable from a local electrical factor should be much cheaper

Few electrical factors in the UK sell 3-core tinned cable.

 

[mrangry]

ASAP appear to be cheaper than eBay sellers too

 

[rogerthebodger]

Few electrical factors in the UK sell 3-core tinned cable.

What about this

OCEANFLEX Marine Tinned 3 Core Thin Wall Cables

1.5mm Marine Tinned 3 Core Thin Wall Cable - 30m

28 .98 quid for a 30 m reel.

ASPS 45 + GBP

1.5mm 21 amp 16 Awg 3 Core Tinned Copper Marine Cable

Some one else.

OceanFlex Three Core Tinned Cable 3 x 1.5mm² - 21 Amp 3 CORE TINNED AUTO MARINE CABLE [ALM Part Reference - MC03T] - - It's Free! : ALM Solutions, Auto Electrical Parts and Accessories for Cars, Boats, Caravans and Campers

 

[pvb]

ASAP appear to be cheaper than eBay sellers too

Your best value supplier would probably be Furneaux Riddall - only £35 for a 30 metre reel.

 

[pvb]

What about this

OCEANFLEX Marine Tinned 3 Core Thin Wall Cables

1.5mm Marine Tinned 3 Core Thin Wall Cable - 30m

28 .98 quid for a 30 m reel.

You're replying to, and quoting, my post which said "Few electrical factors in the UK sell 3-core tinned cable." Furneaux Riddall aren't a "local electrical factor", they're a marine/leisure specialist.

 

[rogerthebodger]

You're replying to, and quoting, my post which said "Few electrical factors in the UK sell 3-core tinned cable." Furneaux Riddall aren't a "local electrical factor", they're a marine/leisure specialist.

So They are still a lot cheaper that ASPS

 

[pvb]

So They are still a lot cheaper that ASPS

Look, you said that a "local electrical factor" should be cheaper (post 5). I suggested that local electrical factors didn't usually sell the stuff (post 6). Then you post a link to a specialist marine/leisure supplier, but get the price wrong (post 8, although you might have edited it yet again once I post this!)

 

[skipmac]

I have purchased an Aqua signal 34 masthead tri colour and anchor light to replace the old existing unit when the mast comes down next week. Whilst down I also intend to run a new tinned 3 core cable, but in a quandary over cable sizing for this job. The cable run from battery to masthead is around 26 metres, the lamp unit is rated at 1.5 watts and the boat`s dc voltage is 12v. I have had a search online but seem to be having a mental block on working this out.....any input appreciated.

I believe the Aquasignal 34 is an LED light with two bulbs, one for anchor light and one for the tricolor nav light. If so then you only need a two core cable, not three.

 

[jwfrary]

It’s a good time to run a new coax for the vhf while your at it as well! As cable goes it’s quite cheap!

 

[skipmac]

It’s a good time to run a new coax for the vhf while your at it as well! As cable goes it’s quite cheap!

Definitely. And if like my boat, all the wires and cables in the mast are wrapped together it might be necessary.

 

[pvb]

I believe the Aquasignal 34 is an LED light with two bulbs, one for anchor light and one for the tricolor nav light. If so then you only need a two core cable, not three.

How does that work then??

 

[skipmac]

How does that work then??

Of course you know that LEDs only conduct in one direction. So tie the leads of the Aquasignal together but reversed IE red to anchor light tied to black of nav light, etc. Then feed the light with one 12V supply but use a DPDT switch to reverse polarity of the power to the masthead. So one way the anchor light works and the nav light doesn't. Reverse power and the nav light works, the anchor is off.

 

[pvb]

Of course you know that LEDs only conduct in one direction. So tie the leads of the Aquasignal together but reversed IE red to anchor light tied to black of nav light, etc. Then feed the light with one 12V supply but use a DPDT switch to reverse polarity of the power to the masthead. So one way the anchor light works and the nav light doesn't. Reverse power and the nav light works, the anchor is off.

Technically feasible, bit rather clunky. And the OP would probably want to use his existing switches.

 

[skipmac]

Technically feasible, bit rather clunky. And the OP would probably want to use his existing switches.

Not clunky at all. Did this on my boat, it works a treat and took 15-20 minutes to wire up. Just added the DPDT switch to an empty spot on my DC panel. Fit like OEM. The power wire to the masthead already has to run to the switch panel so instead of a larger three wire you only need a smaller two wire cable. The 12V power of course is already at the panel so most of the bits are already there. If I recall I only needed a couple of short jumpers to make it work. I'll dig up the wiring diagram I made and post it later.

 

[skipmac]

Here's the wiring logic. In practice there are a few ways to do this. Use a 3-way crimp in the 12V DC +/- feeds to the switch to make Ys to the switch OR use short jumpers between the connectors on the switch. The one I used has male spade connectors so crimped two jumpers with two female spades to wire the DC. Also use a three position switch with