Originally Posted by Chotu
But I wonder why we don’t use fuses and switches. Or standard circuit breakers and switches.
When I completely rewired my boat a few years ago I did exactly that.
BlueSea makes ATO/ATC fuse blocks for good reason.
Here was my thought process when I rewired my boat....
1. Many CB panels are small and end up becoming a rats nest of wires over time as systems are added (or they are huge, and still overloaded).
2. Many circuit breakers have way too many wires (devices) connected to a single CB.
3. Many people use the CB's as switches (often to make power available to a device that also uses a switch to turn on/off)
4. CB can fail over time (esp. the more they are cycled)
5. It is damn hard (nearly impossible to find low amperage CB (e.g. 1 amp) for sensitive electronics which is why most electronics have...yep...IN LINE FUSES!!!
6. If a fuse (or CB) blows...there is a problem. Fuses can react slower then a CB...so if a CB blows because of a power surge....it is a likely indicator of a faulty CB, if a fuse blows due to power surge you like have a fast blow fuse instead of a slow blow fuse.
7. Powerwerx makes "resettable" fuses....so ignore the CB reset argument.
8. Many CB are oversized for the circuits they are protecting.
9. I designed my electrical system
so each device is protected by a single fuse. If a fuse blows...I know exactly what device caused the failure.
10. Lights are fused by zone. (Forward berth, head
, etc). If turning on a light in that zone fails, I try another one...if 2 lights fail to turn on...I probably have a blown fuse, if the second light turns on...I need to replace the failing LED light fixture.
11. There is a single remote
switch to power off all DC loads (except refer, bilge
pumps) if I leave the boat for any length of time. When I get to boat I push the BlueSea 7700 remote battery
switch to make power available to all circuits.
12. I added a small LED light panel at my nav station that will lite to show me if a fuse to a critical circuit blows (e.g. water
pumps, refer, bilge & sump pumps).
13. If a fuse blows...I have spare fuses separated by size in a box that is securely affixed to the inside of the fuse panel door. I don't have to search for fuses, and they certainly take up no additional usable space.
14. I've never experienced a problem with corrosion
(but my boat is dry, and I use Boeshield T-9 on ALL electrical connections).
15. I eliminated all inline barrel fuses (which do tend to corrode over time).
16. All navigation
lights (nav, anchor
tri-color, steaming, deck/spreader, cockpit
, aft flood etc) are controlled by switches, not by CBs used as switches. (All other devices have their own built in power on/off switches.)
Essentially...if a fuse or CB blows...there is a problem that needs to be investigated. Simply resetting a CB could be hiding a bigger problem. I use quick disconnect terminals on all devices (no barrel connectors) or ring terminals in watertight terminal boxes below the cabin sole
, so if a fuse were to blow...I would disconnect the device, and begin troubleshooting the problem. Fortunately...in 7+ years...I've never had a fuse blow. Also, in re-wiring my boat...I replaced all the old corroded bare copper wire with tinned wire of the appropriate size.
I have a single switch that applies power to all circuits (except bilge and refer which are always on) and a handful of switches for nav/safety lights and AIS
on/off & AIS
xmit on/off at the nav station. Engine
fan is fused and comes on when I start the engine
and shuts off 1 hour after stopping the engine using a Powerwerx APS-12 power switch/timer...no need to remember to throw a switch or CB.
And I should mention that my AC circuits use circuit breakers (1 Master and 5 zones).
In the time since I rewired my boat I have found one minor issue with the fuse block solution. I don't run my water
maker these days to refill my forward water tank because I am mostly stuck at a marina. My deck
wash down pump
is plumbed to my forward tank (maybe a bad setup on my part). When it ran dry while out for a weekend...the pump
continued to run until I removed the fuse. It was a little inconvenient...but that will teach me to make sure I fill the forward tank before heading out when i'm not running my water maker daily.
The other downside to fuse blocks is that they are hidden, so I don't have that really impressive looking circuit breaker panel that will impress my guests.
So, IMHO...the debate over fuse blocks vs. cb panels is really a mute point. Of course the zealots won't let it go.