Getting on with boat re-build

[Bugatti]

progress.

blacklab, that is impressive electrical artwork


Cheers, Bug

[blacklab99]

Question to those electrical Guru's.

I have a blue seas 6 gang switch panel at the helm, with a maximum of 15 amps per circuit.
The deckwash down back, rates at 18 amps, which recommends 14 AWG or heavier, dependent on distance, I have about 6 meters of cable length from switch panel to where the deck wash is being mounted down port back.
I'm exceeding the switch panel circuit amperage specified, while the entire switch panel has a combine 90 amp rating, I don't think it would be wise to exceed the 15 amp per circuit max. I was going to go higher in wire gauge to allow for voltage drop over 6 meters, but here's my question.
Is it possible, to run, a cable, be it 14 awg, down aft, to a relay of sorts, then from the relay direct to the deck wash pump ??.
From what I understand, the cable, from the switch panel, to the relay, won't need to exceed the 15 amp switch panel rating, then a heavier gauge wire, from the relay to the deckwash, which would be a shorter length ( less voltage drop).......
Am I on the right track here ???
I don't understand how this would be wired up, I suppose direct to the battery ?,,, but interested in options, or the above is basically what I need to look at.....
The only reference I have to check out, was a mates boat, he actually solved his issue, by putting a deck wash switch at the transom, I suppose that would be a good option, your down back when u need to use it, I guess I would prefer control of it at the helm, just me,, someone accidently switching it on etc, rather have it controlled up front......

Col

[ducky]

Put the relay in the helm with the other wiring, fused independently and switch the relay using your desired switch?

[blacklab99]

I was trying to utilise the switch panels I have installed at the minute, I'm running out of room for separate switches lol.
But if I have to, to make it work, I shall do that, So, it's really just a case of finding a suitable/capable switch to cover the 18 amp draw, then use appropriate cable and run down back to the deck wash ??.
Be nice to have it on the blue seas panel but LOL.

Col


edit, or have I read that wrong Ducky ?
was that, to actually use the existing blue seas switch, but install the relay up front ? then wire from relay to deck wash, sorry, I'm slow on the uptake here

[ducky]

So use the switch in the panel to switch the relay and not the load. Have the relay behind the panel and have that turn the load on. Separately fuse it with say a 20A auto reset circuit breaker so you shouldn’t have to access it on the water.

[blacklab99]

Ok, we posted at the same time there.

Gottya, same as what I wanted to originally do, but instead, fir the relay up front behind the helm......
That will work great and keep everything on the blue seas switch panel and under the max ampage at the switch....

Thanks Ducky, couldn't work it out in my head properly, so far, I've managed to nut thru this re wire for the low amp gear.
Sure does make the grey matter work overtime, when it's not a skill you use much...

Cheers

Col

[SteveoTheTiger]

The only reference I have to check out, was a mates boat, he actually solved his issue, by putting a deck wash switch at the transom, I suppose that would be a good option, your down back when u need to use it, I guess I would prefer control of it at the helm, just me,, someone accidently switching it on etc, rather have it controlled up front......

Col

I cant help you with the electrical issue. I would love to learn that stuff, but at it is i have no idea.

However on my old Quintrex Fishmaster i did have a deck wash and the switch was mounted down the back on the engine well if i remember correctly. I have considered adding a deck wash to my SLR and if i did i would mount the switch at the stern again. I liked it there as that was where you were when you wanted to use it. All the other switches were mounted on a panel on the dash.

[Nude up]

What’s the advantage of the switch at the stern, mine is on the helm switch it on it runs till it hits the right pressure then cuts out sits idle till you pull the trigger then the pump fires up.

[Gultch78]

I run large draw accessories such as deckwash and huge bilge pump from relays mounted right next to battery in back corner of boat and switch up front to turn on relays when needed so no need for big cable going to front of boat and then back again can post pics tomorrow in daylight if u need clarification

[Bugatti]

So use the switch in the panel to switch the relay and not the load.

I cant help you with the electrical issue. I would love to learn that stuff, but at it is i have no idea.

(Steveo, I shall add a bit of a basics to this reply, hope it helps)



blacklab, I'd put the relay (solenoid) behind at the helm area, where I think all wiring components should be, easier to get to, especially when out at sea, AND generally a dryer spot for components. It does mean though, that for heavy loads, you run heavier wire up and back, in-lieu of lighter switch wire up and back, if a relay is mounted at the stern of the boat.

And as ducky said, I'd use the switch in your panel to actuate the relay (solenoid) not the load of the deck-wash. For those that may not know, a solenoid is an electrical switch that is often used where a high current circuit, is brought into operation by a (mechanical/flip) low current switch.

Unless you have a wire feeding the bus-bar that can cope with the accumulated amps of all the wires leaving the bus-bar (including the deck-wash) I'd either , , , , upgrade the wire to the bus-bar and then draw your 18 A wire from the bus-bar OR run the deck-wash load wires (18 A) directly from the battery through the relay (solenoid) then to the deck-wash, , , , and only the actuating wires for the relay to a switch in your switch panel. And as you said, heavier gauge wire than is required for the longer length required, especially up and back to/from the helm. For those that may not know, the longer a wire travels, the more resistance the wire has for the current (Amps) to travel through, which drops the voltage at the end AND heats up the wire, even melting it if it gets too hot.



Straight from the battery

Or from the bus-bar

Cheers, Bugzzzz