Should +ve and -ve wires be the same diameter?

C

chrisbitz

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I've just got a very nice switch panel from china, and curious why the black wires are a thinner than the red ones?

I had a feeling that the amperage makes no difference whether it's -ve or +ve? Is that correct?

All may not be lost, but worst case, I have to replace the black wires with thicker ones...

it was still a great bargain!

(8 way illuminated switch panel with circuit breakers for £54)
 
Same current through feed and return = same mm2 required, either the + is oversize or the - is undersized, work out the total load that will be shunted through it and use appropriate feed and return cables regardless of what is supplied. What is the total load the thing is rated for, assuming it is even CE marked at all.
 
>I've just got a very nice switch panel from china, and curious why the black wires are a thinner than the red ones?

I've never seen that and wouldn't have fitted it on my boat. As ever you get what you pay for.
 
I once bought a modestly priced but branded panel. I took one look at it and returned it. For £20 more the Blue Sea one I eventually fitted was streets ahead in terms of design, quality and safety.
 
KellysEye said:
>I've just got a very nice switch panel from china, and curious why the black wires are a thinner than the red ones?

I've never seen that and wouldn't have fitted it on my boat. As ever you get what you pay for.
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Couldn't disagree more. That sort of blanket mantra is what keeps rubbish companies in business. I assume you'd happily pay £80 for an Armani t-shirt, because "you get what you pay for?" Nonsense.

I agree that sometimes, better quality stuff costs more, but NOT always. I have plenty of 3 year old power tools that I ought very cheaply from Lidl. And they're still working as well as the day I bought them.

By all means buy hand made Swiss socket sets all you like, but don't pretend that anything that's not over priced is "cheap" quality.

The panel has the same switches and contact breakers that I would have bought from RS anyway, and they're all neatly mounted on a metal panel, and wired up neatly with heatsshrink too, for about the same price that I'd have paid for the component parts.

Or I could have bought a similar panel handmade from that expensive place for about £300.
 
chrisbitz said:
Couldn't disagree more. That sort of blanket mantra is what keeps rubbish companies in business. I assume you'd happily pay £80 for an Armani t-shirt, because "you get what you pay for?" Nonsense.

I agree that sometimes, better quality stuff costs more, but NOT always. I have plenty of 3 year old power tools that I ought very cheaply from Lidl. And they're still working as well as the day I bought them.

By all means buy hand made Swiss socket sets all you like, but don't pretend that anything that's not over priced is "cheap" quality.

The panel has the same switches and contact breakers that I would have bought from RS anyway, and they're all neatly mounted on a metal panel, and wired up neatly with heatsshrink too, for about the same price that I'd have paid for the component parts.

Or I could have bought a similar panel handmade from that expensive place for about £300.
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+1 for that.
 
Lazy Kipper said:
DB Doh!
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Me too!

A mate of mine has a Vanquish S, a 6.0 V12 I believe, I was going to say he's not mentioned any problems with it but as it's only done 3k miles in 5 years on dry roads only, not a great example of the reliability!

Wire sizes to cars in 10 posts Thread Drift at its best!
 
chrisbitz said:
I agree that sometimes, better quality stuff costs more, but NOT always. I have plenty of 3 year old power tools that I ought very cheaply from Lidl. And they're still working as well as the day I bought them.
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I've 1,000's of switch panels on Westerly's and Sealine's over 25 years old and still going strong, it's all cost and what is a working life.


Brian
 
chrisbitz said:
http://www.ebay.co.uk/itm/DC12V-8-G...ck-/151063839569?ssPageName=ADME:L:OU:GB:3160
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Those look like Carling V series switches with Contura 3 fronts/actuators. These have been very widely used in boat dashboards for perhaps 15 years and are outstandingly good quality. IP66 and 68, from the front. That panel with 8 of them is good value. They were made in mexico not china, last time I looked

They could of course be Chinese copies, but that is easy to check by examining one of the switches

As someone said the black wires are just for the lights

If they are not on the main dashboard and you do not need 100% perfection looks-wise, you can print legends easily using white-on-clear TZ tape, like the picture below. If you want perfection Axon Components will print/etch any legend you want onto actuators, with red backlighting or whatever, but this does add cost. The actuators pop off and can be swapped - easier done with Carling's special tool which is a sort of plastic 2-pronged fork

IMG_0851.jpg

IMG_0854.jpg
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The red wires need to be bigger as these are the supply wires. Black wires are for returning the exhausted electrons back to the source (battery etc), and doesn't need to be so big as the electrons have all the energy used up in the device they powered.
Big fat electrons carrying a load of power need big wires. Spent electrons returning exhausted can squeeze through much thinner wires.
 
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