I don’t want to have to get another fuse box if I don’t have to , so can I double up on say on a couple sets of 4 led puck lights, super low draw ,I have 3 x 1/2 inch 12 v ball valves for draining grey water tanks very intermittent use also low draw, is this a no no ? Thanks guys
Can you double up on a circuit on the blue sea 12 circuit fuse box ?
- Thread starter Roktman
- Start date
llamalander
Well-known member
Of course, it's called a lighting circuit or a pump circuit.
If you work backwards to the fuse panel, you can design it to work well & safely.
Start with the watts each device on a circuit needs at peak draw, add all those together, divide by the voltage (nominal-for autos usually 12-v.).
4 x 9-watt lights = 36 watts on 12-volt power = 3-amps
Measure the total distance between the fuse panel and the farthest device, double it, because the current returns through the neutral. This assumes that you are wiring the lights in parallel, which means your hot (black wire) is joined to the hot of each device, and it does not need to go through each device to power the next (in the black, out the other, in series). So every light has the hot connect to the hot, and the neutral to the neutral wire.
Look at the chart from Blue Sea to see how big a wire you should run to power the circuit (depending on how many volts a device can tolerate loosing before it fails to function)
www.bluesea.com
Then take a look at their next chart, which shows the fusing options and gives a range of fuses that will protect the wires & devices without blowing.
www.bluesea.com
These are just charts, the data work with any wire/fuse--not specific to Blue Sea products.
What you'll notice is that a certain point, it is less hassle to add another circuit rather than increase the wire size going to each device, or too many things might go offline if a single fuse blows, as Verkstad points out.
If you work backwards to the fuse panel, you can design it to work well & safely.
Start with the watts each device on a circuit needs at peak draw, add all those together, divide by the voltage (nominal-for autos usually 12-v.).
4 x 9-watt lights = 36 watts on 12-volt power = 3-amps
Measure the total distance between the fuse panel and the farthest device, double it, because the current returns through the neutral. This assumes that you are wiring the lights in parallel, which means your hot (black wire) is joined to the hot of each device, and it does not need to go through each device to power the next (in the black, out the other, in series). So every light has the hot connect to the hot, and the neutral to the neutral wire.
Look at the chart from Blue Sea to see how big a wire you should run to power the circuit (depending on how many volts a device can tolerate loosing before it fails to function)
Part 1: Choosing the Correct Wire Size for a DC Circuit - Blue Sea Systems
Engineering high quality marine electrical components for safety, reliability and performance
www.bluesea.com
Then take a look at their next chart, which shows the fusing options and gives a range of fuses that will protect the wires & devices without blowing.
Part 2: Select a Fuse and Fuse Holder For Your DC Product Installation - Blue Sea Systems
Engineering high quality marine electrical components for safety, reliability and performance
www.bluesea.com
These are just charts, the data work with any wire/fuse--not specific to Blue Sea products.
What you'll notice is that a certain point, it is less hassle to add another circuit rather than increase the wire size going to each device, or too many things might go offline if a single fuse blows, as Verkstad points out.
CMARJEEP
Observer
Not a problem as long as you size the fuse for the smallest AWG wire on the circuit.
For example say you have two sets of lights wired to the same fuse and one set of lights is wired with 14awg wire and the other set is wired with 16awg, you would want the fuse to be sized for 16awg.
For example say you have two sets of lights wired to the same fuse and one set of lights is wired with 14awg wire and the other set is wired with 16awg, you would want the fuse to be sized for 16awg.