DC Wiring help

[pc1966]

I tried the second smaller battery at the unit itself and it allows the pump to run but the automatic functions don't work (its activated via relay when the water level reaches a set height)

Were you able to measure the pump voltage during that sort of test?

 

[pc1966]

Thanks for that, I need to get my hands on some 4 core cable as it requires 2 for the power and 2 for data out and pulses from relay in. I already have conduit buried so hopefully I can just hook onto the cable in there and pull the thicker wire through

You wont need thick conductors for the "data" side, so if you have to use a single big cable then look at 2.5mm 7-core as then you can have 2 for "data" and the remaining 5 can be a 2-parallel for '+12V' and 3-parallel set for '0V' to keep the DC power impedance down.

For example:

H07RN-F Rubber Cable - 7 Core 2.5mm2 / HO7RN-F-7C-2.5

Buy H07RN-F Rubber Cable - 7 Core 2.5mm2 / HO7RN-F-7C-2.5 | Order By 1pm For Same Day Shipping | Free Delivery Over £250 *Conditions Apply |

www.cse-distributors.co.uk

 

[pc1966]

It is quite a chunky cable though, but hopefully you can use a 25mm hole-size cable gland to grip and seal it.

 

[pc1966]

If the cable is in duct and protected from direct sunlight, etc, you could use something a bit lighter such as 12-core 1.5mm 'YY' control cable:

YY Cable 12 Core 1.5mm2 / YY-12C-1.5

Buy YY Cable 12 Core 1.5mm2 / YY-12C-1.5 | Order By 1pm For Same Day Shipping |

www.cse-distributors.co.uk

Again, the idea is 2 cores for data and remaining 10 cores as 2 * 5 sets giving the equivalent of 7.5mm conductor sizes for power.

 

[pc1966]

Also available as 'SY' with a steel braid for some protection (nothing like SWA though):

Superlec 12CORE 1.5MM SY PVC CONTROL CABLE - BS EN 50525-2-11 CLASS 5

OVERVIEWSY cables are used as an interconnecting cable between fixed and mobile equipment in conveyors, assembly lines, production lines and machine tool manufacture where the galvanised steel wire braid armour gives excellent mechanical protection.

www.superlecdirect.com