Once known as Hartley18
Join Date: Aug 2007
Location: Melbourne, Australia
Thanked 65 Times in 65 Posts
Rep Power: 9
If it is true that the switching is negative it means that there are always 2 hot wires in the bilge. With engine and its attachments being the common ground and also in the bilge that sounds like a problem waiting to happen.
Well.. one hot wire at least.
I don't have the manual for my specific one with me, but this is what I find on the web for something similar (ie. cheap!!):
Note that the fuse is in the negative return and positive is applied to the bilge switch whenever it's in 'auto'. I'd still call that 'negative switching' because if the fuse blows ("switches") then you still have +12VDC in the bilge - wired direct from the battery even!
To my reading of Maine's ABYC E-11 posted above, this system complies. If that's the best you can come up with, with no requirement for positive isolation and protection, I'm sure glad we don't mandate ABYC standards over here!!
"Honestly, I don't know why seamen persist in getting wrecked in some of the outlandish places they do, when they can do it in a nice place like Fiji." -- John Caldwell, "Desperate Voyage"
Last edited by Classic30; 06-01-2011 at 09:24 PM.