Second Bus wiring size

Basic electrical and electronics, such as DC/Analog control.
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Second Bus wiring size

Postby mdn7 » Sun Jan 02, 2022 9:15 pm

I intend to have a second power bus for,points,signals,decoders etc.
I would like to enquire what wire size is best for both power bus and droppers? TIA....00 layout approx. 16'x8'

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Re: Second Bus wiring size

Postby Suzie » Mon Jan 03, 2022 12:43 pm

You probably just need to worry about wire designed to take the current that the booster supplying the bus can supply. You should not have to worry about shorts or overloads so the requirement to be extra beefy as on the main bus to avoid losses due to skin effect and inductance of the cable is not there.

I do not see any need to use wire larger than 1mm^2 which should be good for 10A, and you could probably get away with using 16/02. Droppers will not need to be larger than 7/02 or similar.

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Re: Second Bus wiring size

Postby Bufferstop » Mon Jan 03, 2022 1:49 pm

As Suzie says you only have to worry about the worst you power supply can do, that's feed a short circuit bad enough to draw just slightly less than one that would make it trip, which is usually it's max rated output. So if your PSU is going to be able to supply 5amps all day without tripping, your cable must be able to carry 5amps in the event of a less than full on short circuit fault, say one pulling 4.5amps. So 5A cable at least.
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