Hi all,
Thanks for any input, as have been struggling to confirm I'm heading in the right direction.
Have a boat that has been wired with incorrect cables, they are far too small, poorly done etc, so im going to replace all of them so know it's right and clean etc. It's a 12v set up, from 2 leisure batteries (starting is separate battery and wiring and ok, so leaving that alone).
There isn't much to power to be honest, couple of pumps, running lights, cabin lights, few gauges, horn etc. But I want to add 2 spot lights at front (has 1 presently which doesnt work) and some usb sockets in the cabin for phone charging etc.
Batteries are in the stern (back) and spots will be at the very front, which is a run of circa 28ft. The wheel house with switches and gauges is circa 1/3 from back to front, and the usb sockets will be circa 2/3 toward front.
So my issues / questions:
The spot lights are 55w each, so I'm thinking I need heavy 16mm or 25mm cable to ensure low voltage drop (current spot is on 2.5mm, no wonder it doesn't work), is my math correct?
Should I power each spot via separate cables, I.e. 2 pos and 2 neg cables all the way (there is no chassis to ground, so have to run all the way back to batteries), or power both by a single pair of heavier cables?
As I need to 'tap in' to the power (and ground of course) at 2/3 and 1/3 distance, hows best to do this? Can i cut the main power cable at each location and power a fuse box, and simply attach the main power cable to the same bolt lug on the fuse board, so in effect the cable is constant, with the fuel box proving power for the accessories at both locations? If not, what type of fuel box do i need that has main power in and a main power out?
For the ground 'splits' can I do the same but just use a bus bar, so main ground cable is attached at 1 end, and attached at other end to move to next location, whilst providing accessory ground points?
If both the above are ok and how to effectively tap off the + and - will this impact my cable size selection? Ie as add additional resistance.
If can't 'split' a single heavy cable, ill need to install 3 sets, 1 to wheel house, 1 to cabin and 1 to the spot lights, which seems like a lot of cable!
Last one for now, will I need to drive the spot lights from relay(s)? Current draw will only be circa 9.2amp for the pair (110w), but I'm unsure how i could attach 25mm cable through a normal switch which can handle the current, but has standard blade connectors.
Sorry for length, hard to describe in words, especially when do not know correct terminology. But like this ( if shows up correctly):
Batteries + ------ 'split' for fuse box for switches horn etc ----------- 'split' for usb points ------- 2 spot lights
Batteries - -------------------- bus bar for grounds ----------------------------- bus bar for grounds ---------- spot light -
Many thanks.
Thanks for any input, as have been struggling to confirm I'm heading in the right direction.
Have a boat that has been wired with incorrect cables, they are far too small, poorly done etc, so im going to replace all of them so know it's right and clean etc. It's a 12v set up, from 2 leisure batteries (starting is separate battery and wiring and ok, so leaving that alone).
There isn't much to power to be honest, couple of pumps, running lights, cabin lights, few gauges, horn etc. But I want to add 2 spot lights at front (has 1 presently which doesnt work) and some usb sockets in the cabin for phone charging etc.
Batteries are in the stern (back) and spots will be at the very front, which is a run of circa 28ft. The wheel house with switches and gauges is circa 1/3 from back to front, and the usb sockets will be circa 2/3 toward front.
So my issues / questions:
The spot lights are 55w each, so I'm thinking I need heavy 16mm or 25mm cable to ensure low voltage drop (current spot is on 2.5mm, no wonder it doesn't work), is my math correct?
Should I power each spot via separate cables, I.e. 2 pos and 2 neg cables all the way (there is no chassis to ground, so have to run all the way back to batteries), or power both by a single pair of heavier cables?
As I need to 'tap in' to the power (and ground of course) at 2/3 and 1/3 distance, hows best to do this? Can i cut the main power cable at each location and power a fuse box, and simply attach the main power cable to the same bolt lug on the fuse board, so in effect the cable is constant, with the fuel box proving power for the accessories at both locations? If not, what type of fuel box do i need that has main power in and a main power out?
For the ground 'splits' can I do the same but just use a bus bar, so main ground cable is attached at 1 end, and attached at other end to move to next location, whilst providing accessory ground points?
If both the above are ok and how to effectively tap off the + and - will this impact my cable size selection? Ie as add additional resistance.
If can't 'split' a single heavy cable, ill need to install 3 sets, 1 to wheel house, 1 to cabin and 1 to the spot lights, which seems like a lot of cable!
Last one for now, will I need to drive the spot lights from relay(s)? Current draw will only be circa 9.2amp for the pair (110w), but I'm unsure how i could attach 25mm cable through a normal switch which can handle the current, but has standard blade connectors.
Sorry for length, hard to describe in words, especially when do not know correct terminology. But like this ( if shows up correctly):
Batteries + ------ 'split' for fuse box for switches horn etc ----------- 'split' for usb points ------- 2 spot lights
Batteries - -------------------- bus bar for grounds ----------------------------- bus bar for grounds ---------- spot light -
Many thanks.