Reply With QuoteOriginally Posted by cehart
What type of fuse and what rating? Jaycar are a good start. You will have to ask as they keep additional sizes in one off's behind the counter.
Just ordered a switch panel, 6 rocker style switches plus 3 sockets, 1 x Cigarette, 1 x dual usb (2x 2.1A), 1 x voltmeter
I can get the fuse sizes for what I will be connecting to the switches ie lights/sounder/gps etc but can't seem to find the sizes that I would need for the 3 sockets
Can anyone here advise
Thanks
What type of fuse and what rating? Jaycar are a good start. You will have to ask as they keep additional sizes in one off's behind the counter.
Fuses are blade, the rating would depend of what's required for the 3 sockets, I have no more information that what I posted. If I knew what the ratings were I would not have asked here
Sorry - read your original post as simply couldn't locate the fuses - not had no idea as to the required current rating. We have no idea of the quality of the fittings - as an example some cigarette lighter sockets are capable of supplying 20 amps - some almost start to melt at 10. Most manufacturers rate their fittings for a maximum amperage or wattage. Are your USB sockets individually fused or does one fuse feed both? The voltmeter probably won't be fused but if it is, a 2 amp would be more than adequate. The USB sockets supply just over 10 watts of power - at 12 volts that equates to roughly 1 amp per socket. If the cigarette socket is a plastic ebay special, personally I wouldn't fit anything bigger than 10 amps.
Currently the panel (baintech, probably same bits as what the cheap flea bay panels are away way but their blurb indicates otherwise, who knows) has 3 x 15 amp fuses, 1 fuse per socket and 2 x switches, but I intent to run to a fuse block like blue seas or bep and have the switches individually fused, just trying to determine whether to run one fuse for the 3 sockets like 15amp or fuse them individually. If I run say 1 x15 amp fuse based on the ciga socket, as to what is there now, would this make any difference to the usb and voltmeter given that their ratings are a lot lower. I'm assuming that the if the usb only draws 2.1A thats the max output, could anything go wrong that could fry you phone if its fused higher, if that makes sense. Trying to get my head around this electrical caper
I'm just doing mine, if you go thru my thread "electrickery".
I would fuse everything separately, no good having a 2 amp usb fused at 15 amps, from my reconing and whats been explained to me.
I'm running the cig lighter and 2 usb's direct to the blue seas fuse box, so it's basically live when the batter is switched to on, not running it to a switch panel, same as my radio and VHF. My Cig socket is fused at 10 amps and the USB dual port is fused at 5 amps at the fuse box...
It's a hard caper to get your head around this Electrickery caper, but have had some great help here,,Scott is your man.... I am fusing each circuit separately, if a circuit or electrical item is rated to 2 amps, then that's what you should fuse it at, there's a reason for why they rate them....
Col
I'm also looking at fitting a battery isolator given that this panel has a voltmeter and usb which aren't switched and would be constantly on, removing the leads off the bat every time would be a PIA. Have checked out a few, some has AFD, what does this do. I would connect this isolator to the motor and fuse panel, I've seen a schematic on the blueseas site which seems to make sense but is this AFD needed?
Cheers
A fuse is not a device that will protect an electronic item from failure - not primarily at least. Typically the fuse blows because the electronic item has failed for whatever reason and draws excessive current - which could if left unchecked, cause the wiring (or device itself) to overheat and catch fire. A fuses primary job is electrical fire prevention. The protection the fuse offers to the device is the prevention of secondary damage due to the current draw (overheating/ fire). This is more critical in electronic units that can be serviced/repaired as the part that is usually damaged due to overcurrent is the actual circuit board which isn't always repairable. The main exception to this is pumps. They can blow a fuse due to having debris in them rather than a failure at times. They should always be fused at the recommended rating as they will burn out if fused higher and they jamb.
The USB sockets are an electronic voltage conversion device - USB voltage is 5 volts. They may have internal over current protection within their circuitry - thus the fuse size used is more about protecting the vessels wiring than the USB socket itself. That said there is nothing to be gained by fusing at a rating massively above what a device will normally use.
Not on an outboard powered boat. AFD is alternator field disconnect. https://www.bluesea.com/resources/91
And another, if I had my shit together I would have put it all in one post, but one thing leads to another.
In addition to the isolation, I've seen schematics that show a main fuse/circuit breaker between the switch and the fuse panel. Firstly is this needed, I only have a small boat, a 4.2m Stacer and if so to work out the size, I would work out the draw of all the gear, then is any percentage increase added to it.
Cheers
It's certainly recommended. If the positive main cable from the battery switch to the accessory panel short circuits to the hull or a negative, that fuse is the only thing between you and a fire. The value of that fuse is purely dependant on the size cable you use as a main. Use 30 amp cable - then use a 30 amp fuse. Make sure you get a good quality waterproof fuse holder and mount it correctly. The number of fuse holders I see mounted upside down is astounding.
Could a circuit breaker like this be used in lieu of a fuse or is the fuse a better way to go
https://www.bluesea.com/products/713...face_Mount_30A
Yes it could but in small craft that see salt spray, fuses are easier to waterproof, don't leave exposed wire terminals and are a lot cheaper at the size required.
Ah ok, so are you talking about those plastic enclosed ie 30a in line blade fuses or some other type.
Cheers
cehart,
https://www.ebay.com.au/itm/Inline-B...72.m2749.l2649
This is an 'inline blade fuse holder' and has a water-resistant rubber cover that could be given a little silicon to beef up its water resistance. Anything rated for a vehicle of 12V or 24V is OK. No need for a higher voltage rating. The insulation on the wires might not be a super marine grade - perhaps a silicon spray on the wires before they are installed ??
Fuses and circuit breakers are the first thing after the battery. Switches should be downstream from the fuse. Circuit breakers can be reset; fuses are 'blown' and need replacement. Replacement in the wild might be a bit of a worry.
Rgds,
Steve
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