Hi all
I know I need a permanent live (as well as switched) to my new radio (to keep the preset stations) & also a permanent live to the bilge pump (so I can leave the boat with the master switch turned off) and it will trigger in the event of bilge water entry
So the question is
Do i run these permanent lives (which bypass the main switch) through their own switch and them through the main fuse then onto the battery +
This way I still have a switch I can use to isolate the permanent lives in case of future work
TIA
—
Stephen and Julia
Francesca
Macgregor 26x (2003)
Is this the boat I once owned ? Did you buy it from Mike ?
Yes I think so, we bought it last March
It was very basic, pretty much as it would have left the factory I guess
Stephen and Julia
Francesca
Macgregor 26x (2003)
If you want to email me we can chat about the boat. David P.
Hi Stephen
I think your suggestion for wiring the bilge pumps and radio is fine. It's always good practice to be able to isolate any electrical circuit, even if in practice you keep it always-on.
You may also want to consider a special bilge pump switch. Most automatic pumps also have an additional connection to switch them on directly (bypassing the float switch). You can get 3-way switches like this: https://www.force4.co.uk/item/Force-4/Waterproof-Bilge-Pump-Rocker-Switch-Vertical/VUP. Centre is off, Auto connects to the float switch, Manual connects directly and has to be held down, so you can't accidentally leave the pump running. It's really useful for fully pumping out the bilge even when there's not enough water to trigger the float.
Rick Jones (Treasurer), former 26X & 19 owner, Isle of Wight
Hi Rick
That's what I though re having a separate ISO for the permanents
I do have one of those switches
So
auto = permanent live
manual = from master switch & fuse box etc
Cheers
Stephen and Julia
Francesca
Macgregor 26x (2003)
Does this help?
Boat Electrics DC v0.2
Dave Newton Sailbadthesinner
Yeah that's about right, although both diagrams don't have an iso before the bilge pump switch
Stephen and Julia
Francesca
Macgregor 26x (2003)
Stephen, when you say iso do you mean n isolator as in a switch or something else. In this case it would mean a second switch placed in front of the switch used to direct or disconnect the supply between pump and float switch. Seems a little like over kill. What does seem missing from the circuit is a fuse before the switch. This I would use to disconnect the switch if necessary.
Best wishes Jonathan
Hi Jonathan
At the moment I've got the following
Battery +
Main Fuse
Master switch
Main Fused board
So to redirect a live to the fm radio & bilge pumps I was planning to take the following
a new cable of the main fuse
Through a separate switch
to a busbar
then to the radio & bilge
This way I can still isolate them if required although they will probably always be left on
Stephen and Julia
Francesca
Macgregor 26x (2003)
A radio circuit and the bilge pump circuit will each need a fuse of their own (as shown). This is included in most proprietary manual/auto bilge switches. and many radios have an inline fuse in their supply cable (but it may be more accessible to use a panel mounted fuse holder).
Both the bilge pump and the radio have their own switches, adding a further isolator for these just gives you a second way to do the same.
If you wanted to disable either for maintenance you can simply remove the fuse.
One thing to note is that the supply for each of these before their respective fuse is an unprotected battery +ve so should be mechanically protected to prevent any chance of a short. 8mm PVC flexible conduit gives good, lightweight protection from normal abrasion or trapped wires.
It slightly depends if you are talking about a marine VHF radio or a music/commercial radio. The former is safety critical equipment and I would always supply via a circuit breaker so it can be reset quickly if needed. If you're without your music for a few minutes while you find a spare fuse it is hardly the end of the world.
It is common (questionable) practice not to fuse the battery +ve with a master fuse. The argument is that it is safer to simply provide good mechanical protection than risk a blown fuse disabling your engine, navigation equipment and radios all in one go. Conversely there is an increased fire risk from a short circuit but if EVERY load has its own fuse then only the battery +ve cable is at risk and this can be well mechanically protected and kept clear of all other wires especially battery -ve connections.
I have the following equipment connected before my main isolator / battery selector:-
Battery charge/discharge monitor
Solar charger controller
Bilge pump
Security Alarm
VHF radio
CO and gas/vapour alarm
Shore supply charger
These are the items I still want to operate when the boat is otherwise shutdown.
Dave.
Dave Newton Sailbadthesinner