Fuses

[Pudsey Bear]

Always confuse me.

The ciggy socket I fitted yesterday is needing a fuse I think although the thing I used didn't have on in line as I assume it depended on the vehicle providing the fusing, I just cut the plug off and put ring terminals on, it's only for a USB plug so I assume a 5a fuse will be enough, but would like confirmation.

The Belkin Inverter is 300w and that had a fuse in the plug but as above it's on ring terminals, I'm thinking a 10a fuse will be enough, I'd rather go too low than to high so would like help on that too please.

 

[st3v3]

Always confuse me.

The ciggy socket I fitted yesterday is needing a fuse I think although the thing I used didn't have on in line as I assume it depended on the vehicle providing the fusing, I just cut the plug off and put ring terminals on, it's only for a USB plug so I assume a 5a fuse will be enough, but would like confirmation.

The Belkin Inverter is 300w and that had a fuse in the plug but as above it's on ring terminals, I'm thinking a 10a fuse will be enough, I'd rather go too low than to high so would like help on that too please.

5A will be fine, assuming the cable is thick enough.

300w at 12V, with no losses, is 25A. What you really need to look at is what fuse the inverter instructions say it should have. Or somewhere on the case/plug you cut off. Even the old fuse will have a rating on it.

 

[mistericeman]

Surely size of the cables is the most important bit....?

 

[st3v3]

Surely size of the cables is the most important bit....?

Yes, but this seems to be a pre-wired thing. He said he cut the plug off.

 

[Pudsey Bear]

Yes it's the cables I'm trying to protect as they are no coiled or anythign just out of site under the beds.

The Bestek (NOT Belkin) inverter has no fuse in the plug at all I just checked, and its still under warranty so I can't open the box, instructions are no help.

Cable on ciggy socket is 18AWG, and has a inline fuse already looks tiny so should be OK. See bad pic of the fuse to the ciggy socket, looks like 5 amp and for now where I've come off the leisure battery I've put a 5a fuse in each holder.

 

[Sprinter 1 cup]

The sprinters start battery is inside cab. I'd run a new wire from there. For any invertor ! as I'm thinking you want the engine 50amp to charge the utility socket ? Not good !. most of them are 10 amp and they get hot warm witch is a loss , at that draw.after a few mins. So 25amp wire rerun min.please You can still put a 5amp inline blade fuse in then 7.5 then 10 then a15 and the 300w inverter will work good

I use these now and solder the wire

What did you do wlth the chair charger?

 

[Pudsey Bear]

Thanks 2 cup

It's all already fitted them with the wiring they came with, I will be shortening the ciggy socket/USB wiring but only for tidiness as it's going to get swapped for a dedicated USB socket when I get around to finding the bagful I bought ages ago, (it has one of these right now https://www.ebay.co.uk/itm/165713721037 ) the Leisure battery is under the seats/bed in the rear lounge so taking it from the starter battery up front would just make more work and add cost to keep losses down, the inverter lead before cutting was less than a meter and is quite thick, too thick for blue terminals so had to use yellow ones.

 

[MatijaSever]

Thanks 2 cup

It's all already fitted them with the wiring they came with, I will be shortening the ciggy socket/USB wiring but only for tidiness as it's going to get swapped for a dedicated USB socket when I get around to finding the bagful I bought ages ago, (it has one of these right now miniature board game ) the Leisure battery is under the seats/bed in the rear lounge so taking it from the starter battery up front https://sharpedgeshop.com/collections/japanese-knives/nakiri just make more work and add cost to keep losses down, the inverter lead before cutting was less than a meter and is quite thick, too thick for blue terminals so had to use yellow ones.

So 25amp wire rerun min.please You can still put a 5amp inline blade fuse in then 7.5 then 10 then a15 and the 300w inverter will work good

 

[Pudsey Bear]

I'm no expert but that seems excessive to run a 100w from.

 

[Squiffy]

Thanks 2 cup

It's all already fitted them with the wiring they came with, I will be shortening the ciggy socket/USB wiring but only for tidiness as it's going to get swapped for a dedicated USB socket when I get around to finding the bagful I bought ages ago, (it has one of these right now https://www.ebay.co.uk/itm/165713721037 ) the Leisure battery is under the seats/bed in the rear lounge so taking it from the starter battery up front would just make more work and add cost to keep losses down, the inverter lead before cutting was less than a meter and is quite thick, too thick for blue terminals so had to use yellow ones.

As for fuse rating I've just fitted a 85cm self seeking dish running sky Q And a Scr switch which is 20v running off 230v ac through reducer bricks so have had to finally add an inverter in the system to A) Run the Scr (Single cable operation) and B) Also run the Sky Q box.
The inverter is a 600watt non pure sine wave 12v inverter, as the fuse size was an unknown I started off using a 3 amp spade which was only just sufficient ( It blew when both Sky Q and the Scr where turned on together so I then increased the fuse size to 5 amps which is fine it doesn't heat up and runs cold so this is the fuse size I will continue to use. I've also installed a mechanical switch which switches from shore power to inverter depending on where I am parked. In short I would suggest that you place a spade type fuse holder from your cigarette lighter and start with the lowest fuse that will run what ever your trying to charge/use so long as when you are using the cigarette lighter the fuse is less than the recommended amperage of the wire to the cigarette lighter socket then your good to go. Most wiring will take at least 8amps 12V DC regardless unless you have an extremely small gauge wiring. Phil.

P.s. If my wife inadvertently switches on the microwave while on inverter it immediately blows the fuse, and as I've got a box full of fuses it would only take a couple of seconds to replace the 5amp fuse, but a couple of hours explaining to her why we can't use the microwave or electric heating on the Truma 4 while on inverter

 

[Pudsey Bear]

Same with Liz, it just doesn't go in for some reason, I just say ask me now and she does, but it always annoys her, and sometimes words are said.

I think it is time that the constructors fitted a decent size inverter panel and battery bank in the factory, after all even on sites the power is a bit meagre, if they fitted them the economies of scale would make it a worthwhile addition to the new cost so long as they didn't take the piss and it could be warranted along with the rest of the van, a tidy and professional fit.

Fuse and wiring sizes are a pain, I tended to use 4/6/10mm2 on my build, the main reason being I could tap into any cable and know if I was okay just by looking at it.

 

[Squiffy]

Same with Liz, it just doesn't go in for some reason, I just say ask me now and she does, but it always annoys her, and sometimes words are said.

I think it is time that the constructors fitted a decent size inverter panel and battery bank in the factory, after all even on sites the power is a bit meagre, if they fitted them the economies of scale would make it a worthwhile addition to the new cost so long as they didn't take the piss and it could be warranted along with the rest of the van, a tidy and professional fit.

Fuse and wiring sizes are a pain, I tended to use 4/6/10mm2 on my build, the main reason being I could tap into any cable and know if I was okay just by looking at it.

The trouble with inverters I find is they are by nature 12v power hungry if used to power any AC product much over 3-400w and even if switched on but not supplying 240v they are taking ampage from the battery bank. I had to fit this inverter if I ever want to use Sky Q while not on shore power but in all honesty I have managed up until now with just storing the inverter and just connecting to the battery terminals if and when needed. I've found that using the van 12volt system backed up by a 120watt solar panel has been extremely adequate. But for the sake of convenience and not having extention cables running around the floor when we wanted to use the Sky box I have incorporated the inverter into the mains system. To use an inverter on a regular basis would need a battery bank that would take up much needed space in the van and a much upgraded charging system with the present technology.Though Lithium batteries are improving slowly on weight and power output, the cost and required volume still make it debatable in my view. Phil