Wire in new electric toilet

[clivvy]

Hi Guys,

just want to check something, if you dont mind? I want to finally get my toilet wired in, and im a very cautious chap. Will this wire be suitable to wire in a 3amp Thetford C2 toilet? http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=170492569100&ssPageName=STRK:MEWAX:IT

I understand I need to fit, presumably, a 3 amp fuse also on the +VE? the existing electric pump for the taps is setup that way...

thanks in advance,,:bow

 

[Thomas-the-Terrano2]

not really otherwise cable will act like fuse.

if load is 3A then cable wants to be rated
atleast double.

 

[rustic]

kQUOTE=Thomas-the-Terrano2;95045]not really otherwise cable will act like fuse.

if load is 3A then cable wants to be rated
atleast double.[/QUOTE]

You also need to consider the length of the cable as there will be a voltage drop.
On my other computer I had a link to a book, called 12 Volt bible, used for boats using 12 volts with lots of issues that you will find interesting, when I get the computer back I will post the link.
If the current on the motor is 3Amps, the surge on start up will be much greater. 2-3 times, you may even need a higher rated fuse, so the cable needs to be greater.

 

[clivvy]

Thanks for this. So, it seems to me that normal twin core from Wickes will suffice, say 7amp. Wire that into the battery feed but still fit a 3amp fuse? I'm confused about the fuse you see, I thought that because the device is max 3amp, then I can only allow 3 to it...?

 

[rustic]

Thanks for this. So, it seems to me that normal twin core from Wickes will suffice, say 7amp. Wire that into the battery feed but still fit a 3amp fuse? I'm confused about the fuse you see, I thought that because the device is max 3amp, then I can only allow 3 to it...?

Max 3A means that this is the most it will draw, important to know this in a caravan with a limited battery power. Fusing it with a 3 Amp fuse will be ok but worth carrying a 5Amp as a spare in case. If you run a fuse to the limit eventually it will fatigue and eventually blow, even though there may be nothing wrong with the appliance. The fuse protects the cable so ensure the cable is stronger than the fuse, so 7Amp cable will suffice in my opinion.
Hope this helps.

 

[Thomas-the-Terrano2]

Thanks for this. So, it seems to me that normal twin core from Wickes will suffice, say 7amp. Wire that into the battery feed but still fit a 3amp fuse? I'm confused about the fuse you see, I thought that because the device is max 3amp, then I can only allow 3 to it...?

Wickes?, not a big name on 12V circuit pardon pun, twin core 7A, is this mains
cable, perhaps better on Halfords, Towsure or Maplin. !2V doesnt tend to be
twin core, in my experience. That said I have used on economy grounds redundant
lawnmower cable (twin) in low voltage caravan circuits.

7A x 230V =1610W so suspect will suffice for a 3A 12V (36W) dc device.

 

[clivvy]

Max 3A means that this is the most it will draw, important to know this in a caravan with a limited battery power. Fusing it with a 3 Amp fuse will be ok but worth carrying a 5Amp as a spare in case. If you run a fuse to the limit eventually it will fatigue and eventually blow, even though there may be nothing wrong with the appliance. The fuse protects the cable so ensure the cable is stronger than the fuse, so 7Amp cable will suffice in my opinion.
Hope this helps.

Thanks Rustic, yes, this helps a lot and I understand what youre saying, ill get the stuff I need ordered!

 

[clivvy]

Wickes?, not a big name on 12V circuit pardon pun, twin core 7A, is this mains
cable, perhaps better on Halfords, Towsure or Maplin. !2V doesnt tend to be
twin core, in my experience. That said I have used on economy grounds redundant
lawnmower cable (twin) in low voltage caravan circuits.

7A x 230V =1610W so suspect will suffice for a 3A 12V (36W) dc device.

at Wicks, yes, its mains, actually I only need 12V as the toilet is ONLY battery powered. As far as I can see, there is 12 V twin core cable available, its just finding soemwhere that sells it, and round by me, there doesnt seem to be many places although i havent tried Halfords yet I doubt they do it.