wiring on a 50' canoe cove

[wilezcoyote]

we just started to do the 12 volt wiring , My question is:
how far away from the batterys can the DC parallel panel switch be from the batterys and engines , we would like to put the(BLUE SEA) DC parallel panel switch and the(BLUE SEA 8380) DC power distiribution panel in the wheel house which is @25' away from the batterys and engines, I am going to use relays on the large current items. I am using the Boatowner's manual by Nigel Calder


thanks for any help steve

[Tim B]

Relays are a good way to go. They can sit in a sealed box in/near the engine room. Hopefully, your batteries will be somewhere near the relay box.

For light applications (ie. signal or low current) you can use very thin (multi-core) cable and run as much as you want. As the current goes up, though, you need to use thicker cable, and naturally this is heavier. There are two solutions, firstly, switch a 12 volt relay directly (+12v --- Switch --- Relay Coil ---- 0v). Or preferably use a transister to switch the relay, and use smaller, lighter wire to the switch panel, and also smaller switches as you are now switching 2mA, not 200mA per channel.

see http://www.kpsec.freeuk.com/trancirc.htm for more details. you could actually use a transistor to switch the circuit with no relay.

Generally, high-load cables should be kept short, low-load cables will have a volt-dop down them, but this should be ok for transistor/relay purposes.

Tim B.