What you are seeing Mick, is totally normal for an outboard powered rig. The "earth" or negative connection to the hull is via the motor.
What you are seeing Mick, is totally normal for an outboard powered rig. The "earth" or negative connection to the hull is via the motor.
I was waiting for your input Scott.Originally Posted by scottar
Manson Supremes cheaper at about $369 from Whitworths compared to Sarcas $400+ for your boat just having a quick Google then.
It's running the following electronics,x2 Garmin 7015 screens(to be updated shortly to the 8016s),x2 Garmin GMI20, Garmin GSD26 with a Airmar CM275lhw chirp transducer,Garmin radar 64nm, Garmin AIS transceiver,Garmin GHP 20 Marine Autopilot with Smart Pump,Garmin VHF200i,
Garmin Camera,Fusion 750 Head unit,x4 Fusion 7''speakers,Fusion Sub and Amp,Fusion 22''Plasma,
I think I got it all.lol.
Manson Supreme was the one I was looking at,its the 6096 25lb.
All look's sweet Mick. Only thing - what do the lighter gauge wires directly attached to the battery supply and is there any fuse or breaker to protect the them and the mains. Being an alloy hull it is not unusual to eventually get a bit of chafe eventually unless all your cables have been run in conduit. I have seen a few nasty examples where this has happened in a main feed wire with no over current protection that have resulted in a lot of smoke and heat at best - at worst a fire. Any lighter mains feed or accessory feed that goes direct to a battery should have a fuse as close to the battery as possible/practical. This goes for charge lines from solar as well.
The amount of current you can put through a wire will depend upon the maximum allowable voltage drop and the resistance. When I design circuit boards, we often have small copper traces for high currents, but the distance is only small, so you can get away with it (I actually calculate it, then derate it for the expected ambient temperatures). Same occurs for wiring, a small diameter wire can carry a lot of current if its only a short length. Look at the size of the wire in a fuse for example!! Although you dont want your wire the same diameter as the wire in a fuse, its a good example of how much current a piece of copper wire can handle.Mick,
Not having a go at you. At first glance there appeared to be one wire running to the whole system which looked a little small in diameter, hence the question.
I now see there is a secondary one running back around. Looks great.
I'm no electrician by trade and I did do all my own wiring on Moejoes, I searched the net for information in the process to ensure wiring was adequate.
Eg: correct diameter for length run, voltage drop & expected amperage being drawn through them.
Table attached which might help.
Say you want to run 1 meter of cabling ( Including negative, so 0.5 meter Pos. & Neg. )
Acceptable cable diameter would then be 4.6mm2 which you could run a max. of 25 to 30amps through.
That's how I read it, Sparkies feel free to correct me if I'm wrong......
Last thing anyone would want is an electrical fault offshore.
Something I am paranoid about, that is why everything on Moejoes was wired independently & could be easily isolated.
I've got your back Mick
Job looks good though! You got my stamp of approval and I am an instrument fitter by trade (more or less a sparky).
The 2 mid size cables are for the solar panel,they run into the sloar panel regulator.The smaller 2 earth/positive are for a very low draw Relaxen brand LED battery voltage meter.Just so I can monitor the voltage at anchor.
I have included a picture hopefully showing the small gauge.It is just above the fire extinguisher sign.
Remove the motor negative cables off the batteries & test again.
Still worth having an over current protection device in the positive wires for those devices. Breakers and fuses are to protect the wiring and stop fires should a fault situation occur. They do offer a degree of protection to the device in so much that they may prevent a small fault turning into a major fault and possible destruction of the PCB in an electronic device. That fault may be an equipment malfunction where the device creates a short circuit or a wiring fault due to chafe or a connection coming off and touching the hull.
I will need to find out what size fuse to put on the positive cable of the solar panel reg Scott.
I take it that fuse needs to be close to the battery terminal end?
The cable for the solar is thick,6mm by memory,it was the proper cable for solar purchased off Whitworths or Road Tech marine.
Mate, That looks awesome ! Thanks for the pics
Frank
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Hi Mick, you will never stop your motors earthing through your hull unless you isolate them and they more than one earth theses days any way, having a neg charge or otherwise earth in your hull is fine a positive or open circuit running through your hull is bad. To test for this mate use a multi meter and put the earth on your pos on the battery and the pos of the meter on your hull you should het nothing, if you have a open circuit somewhere you will get a current which means rubbed powered wire somewhere which should have a fuse or breaker anyway. Mate i'd be checking your solar reg it may have its own breaker, you would be better off using a breaker then a fuse when mucking around with solar. Nice ship mate, see ya on the water.
You can calculate that from the panel sizes. As an example, a 120 watt panel in theory is good for 10 amps - 120/12 =10. Add up your total panel wattage, divide by 12 and add a bit. I would use a 15 or 20 amp fuse for the 120 watt example I have given on the proviso that the wiring was capable of handling the current. As Michael has mentioned further down, it may be easier with the heavier cable to use a breaker than a fuse. You are correct that the best place for the over current device is as close to the battery as possible. This protects as much of the cable as is possible.
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