secindary fusebox

[jeffdub]

hi everyone could someone advise me on what amp wire i need to run from my leisure battery to my secondary fuse box please ? it will be powering a couple of downlights and a propex heater cheers jeff

[kevtherev]

what wattage are the two together .. is the question jeff

then it's a simple calculation current (amps) = power(watts) divided by Volts (12Volts

[jeffdub]

thanks kev i will have to check the downlights the propex is a 2000w heater i think jeff

[kevtherev]

no that's the gas equivalent ... you need to know what electrical power it requires to run the fan.

Oh and what length is the wire to run

[Oldiebut goodie]

Then also consider the length of cable and the voltage drop - too much drop and your Propex will not work. Use as heavy a cable as much as double what amps you expect to carry if you have a long run to cut down on voltage drop.
I have tested Webasto heaters with long undersized cabling - they just don't like the volts not getting up them!

[jeffdub]

lol sorry kev never thought about that the cable runs from the battery behind the seat to the wardrobe on drivers side rear about 3 metres i think unless i bring the fuse box closer ?

[kevtherev]

need an exact figure jeff, as oldie says propex's dunna like voltage drops

[jeffdub]

thanks lads i will have to get all the figures together and exact length of wire i need then work it out using the calculation and come back and ask you if im right

[jeffdub]

ive just checked my lights and there are 3 lights at 20 watts each and the propex site says it draws 1.8 amps continous running so would that mean 3x20/12 = 5amps + 1.8 amps for the propex say 7 amps total then double it for the 3metre run ?

[kevtherev]

you would need 10mm² cable or (8AWG) for an acceptable 1% loss for that length and amperage

[jeffdub]

cheers kev ive just noticed i cant spell secondary either lol

[kevtherev]

we can accept that you being a brummie and all that

[jeffdub]

http://www.autoelectricsupplies.co.uk/p ... ategory/11" onclick="window.open(this.href);return false; thanks kev is the cable i need the last one on here ?

[billybigspud]

Little late but.......

http://www.solar-wind.co.uk/cable-sizing-DC-cables.html" onclick="window.open(this.href);return false;

Go to the bottom.

[jeffdub]

thanks billy ive saved that page cos ive got a memory of a goldfish so that will come in handy