Submain voltdrop

[Jimmyb]

Hello, im after a bit of advice reguarding the cable to supply a db in a farm shed, the design current is 32a and the run is 61 meters. the vd with 25mm is 3.42 which is going to be ok but i would of liked a little less due lights need to be on 4mm but only by 1v, anyway i rang for a price for 25mm but they havnt got any 2core in till friday so wont give me a price so i ask for a price of 35mm as i was considering this if the cost wasnt ott compared to 25mm so allow for further upgrades, but they didnt have that while friday either, i wanted to get an idea tonight but now everywhere is now closed, i started to think could i just use 16mm 4core and double the wires up the questions are

1. Is 16mm 4core cheaper than 25mm 2 core.
2. Is the vd worked out as normal then just halfed as this better than 25mm or is there a factor to take in account. (e.g 16mm = 5.47/2=2.735 vs 25mm = 3.42)

Thanks

Jimmy

 

[Amp David]

If you double up the conductors then its half as conductor size has doubled. As for price you'll only be able to get the answer to this by ringing around some wholesalers

 

[LlandrilloSpark]

web link below gives 2 core 25mm SWA at £5.09 per metre if you want over 50 and 4 core 16mm SWA at £6.12

armoured swa electrical cable

 

[SPARTYKUS]

Bought 90+ metres of 4 core 16mm SWA 2 weeks ago, 4.43 + VAT per metre. PM me if u want the wholesaler.

Its BASEC before you ask !

 

[Knobhead]

Sparky your getting paranoid :iagree:

 

[Engineer54]

Jimmeyb,

2 Things will always occur, when using parallel cables, ....overall VD figure will fall and current carrying capability will increase. It is more often than not, the chosen method of distributing high current mains and sub-mains around a project. Far easier to terminate a couple or more smaller multi core cables, than one large multi core cable too!!!