Is my wiring diagram any good?

rustybouy

rustybouy

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Hi there, im just wondering if i have my diagram right for my wiring, i think i need to insert two in line fuses, one between the main batt and bilge pump, and one close to the batt inbetween it the isolation switch, and then run all my wiring back from the fuse/switch panel to the battery, i think ive got it right but..., also not sure which size marine wire to use? mabey 2.5mm? any help would be great ybw,
Many thanks Pete (hope my attachment has worked )




View attachment 18151
 
Hi Pete

Your isolation switch is not correctly wired.
If you were to close the switch there would be a dead short across the battery. The correct way to wire the isolation switch is the pos supply to one terminal and the pos to distribution panel on the other. The neg is not connected to the isolation switch.

The cable size will depend on the lengh of the runs.

You have only allowed 2 amps for the radio, if this is a transceiver it will take at least 6 amps on transmit.


You have only allowed 2 amps for the horn, most horns take much more.

The bilge pump supply should have an isolation switch and fuse in the suppy.
I am not sure how you have wired it, but it should be from the supply to the switch, then to fuse, then to one float switch terminal, other float switch terminal to bilge pump and the neg return to supply.

Hope this helps

Alan
 
Single pole battery switches, which are the most common, will only isolate the + so the wiring to the battery switch is wrong, both should be +.
Fuses where you indicate are needed, in addition you should really have some fuses on the separate sub circuits. The easiest way to do this is to by one of the ready made panels which come with fuses or cb.
The size of wire will depend on the length of run, measure the length and I or someone else will calculate the size needed, but it will be much larger than 2.5mmsquared.
 
Last edited:
As has been pointed out, your wiring to the master switch is incorrect. As you have drawn it, the boat could easily catch fire as soon as you switch on as you will have created a short circuit.

You also have a query against the busbars, asking whether you need wires back to the battery. The whole point of using buses is that you do not have multiple connections to the power supply. Also, any such wires would bypass the master switch if taken back to the battery.

Without wishing to be unkind, I strongly suggest that you seek local help with your wiring project. Although this forum may help you to sort out the circuit diagram, you still have to understand it to execute it correctly. The consequences of an error could be very serious and it is not worth the risk of doing youself unless you are really sure of what you are doing.
 
As above re the battery isolator

If you have a switch with three terminals it is probably a 1,2, both, off switch intended as a change over switch between two batteries

Check the fuse values some seem a bit low for the intended application.


Cables must have a safe current rating above the value of the fuse in the circuit.

Long cable runs to voltage sensitive items ( eg filament type nav lights) will have to be heavier than the normal current rating to avoid excessive volt drop.

Yes fuse the bilge pump circuit, fit a switch too perhaps. You may also want to consider a switch that over-rides the float switch to give manual operation.


I strongly recommend you study the boat electrical notes at http://www.tb-training.co.uk/ and get a grasp of the basics before you go any further.
 
wiring.png

This would work.All the fused switches should be connected to the positve and negative bus bars so no need to take them to the battery.An inline fuse in the bilge pump circuit is a must.
 
thanks for your replys fella's, as it stands, i'l be honest here, my wiring is a rats nest, a shambles even, the guy i bought the boat off didnt do a very good job, and im already worried about fire onboard, i really want to rip out everything and start fresh,im not sure if its the untidyness of the current wiring thats making me cringe,i have decided to take it all out, i will record the lay out as i go,for all i know it could be wired ok, ive had a good look at the TB training site and its great info, im sure i can tackle this if i do the proper reasearch, get the proper advice, and keep checking as i go along that everything is safely done, buy the proper equipment.

the amp ratings are just an approx guide that i wrote, my battery indicator does give me the correct amps when i turn on individual things, i will check before installing anything. i will run by everyone the wire lengths, and a new and improved diagram after iv'e gathered the required knowledge.i wont do anything daft.

must check my insurance ;)

thanks again
Pete
 
This is the way you should do it:
The float switch and a 10 amp panel switch should be wired in parallel so you can override the float switch.
A LED lamp and / or buzzer should be wired across the pump so you get an indication when it is on.
 
A LED lamp and / or buzzer should be wired across the pump so you get an indication when it is on.
Click to expand...
An LED indicator by all means but perhaps not a buzzer to an automatic bilge pump.
 
VicS said:
An LED indicator by all means but perhaps not a buzzer to an automatic bilge pump.
Click to expand...

Both are take it or leave it options.
There are occasions when a buzzer could be handy
eg running under engine and pump keeps coming on, you may not notice the LED but you may hear the buzzer that is warning you that the bilge is filling with water.
You can always add a switch in the buzzer circuit if you know that you are filling up ready to DIVE :D
 
At the risk of stating what might be already obvious, when measuring the length of run in order to calculate the wire size, you need the length to AND from the fitting back to the battery.
 
PuffTheMagicDragon said:
At the risk of stating what might be already obvious, when measuring the length of run in order to calculate the wire size, you need the length to AND from the fitting back to the battery.
Click to expand...

Perfectly correct.

Some of the tables and calculators available on line automatically take this in to account. Some don't. Some don't say so you are left guessing.
 
LadyInBed said:
There are occasions when a buzzer could be handy
eg running under engine and pump keeps coming on, you may not notice the LED but you may hear the buzzer that is warning you that the bilge is filling with water.
Click to expand...

The only time my auto pump ever does come on is when the stern gland is overdue a little tightening and I've been running under engine for a while. The pump is clearly audible - had me pretty worried the first time it went off :)

Depends how noisy your pump and your engine are compared to each other, I suppose.

Pete
 
Thanks for the diagram Nigel, much obliged, iv'e been struggling to map out things the way i want,im unfortunantly offshore on my supply boat at the moment and im trying to workout things and order new equipment from memory, i was on here last night reading all the other threads about wiring & fuses etc. and gleaned loads of good info, the one thing that kept coming up was "the fuse is there to look after the wire" " the benifits of having an in line fuse (+) close to the battery" among other gems of info, its been an eye opener for sure, pity i can measure my amps and wire length till i get back home, im dying to get stuck in :D

thanks again lads

Pete
 
p.s , going to put in a three way switch for the auto bilge switch, no light or buzzer needed, i just lift the deck board and look whenever im out and the discharge is easy to see so i'll know if its on or not :D
 
rustybouy said:
p.s , going to put in a three way switch for the auto bilge switch, no light or buzzer needed, i just lift the deck board and look whenever im out and the discharge is easy to see so i'll know if its on or not :D
Click to expand...

The best switch is a single pole double throw that is momentary on one side - the manual side. That way you cannot flip it to manual and forget about it and burn the pump out, or worse the wiring.
 
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