swa help

[rich spark]

Hi guys. Little bit of guidance required please. Have a 260m run to carry a total of 16amps. Just to supply 4 sockets.
Im done my calcs and come out with a size of 25mm 3core swa which will give me a VD of 7.28
The cpc will be plenty big enough after calcs show an 8mm required.
As 25mm impossible to terminate into a socket!!
Was wondering the best way to go about it, would a submain to a DB over half way, and two 16amp mcbs to suply 2x radials be best?
Or submains to 1st point, and then to the 2nd point? So id have two DBs on 1 SWA with one 16amp mcb in each for sockets. Any response greatly apreciated. Thanks

 

[Midwest]

Hell of a run, what is it?

 

[rich spark]

For an External camera run. Power for cameRa switches etc

 

[Octopus]

Are the sockets all at the end of the run or spaced along it?

 

[rich spark]

Two sockets 2/3 of the way and two at the end.

 

[Octopus]

Two sockets 2/3 of the way and two at the end.

OUch. I'm guessing these are outside too!

 

[keniff]

Are they actually going to be pulling 16 amps or is that the size of the mcb?

 

[micknew]

6A radial with weatherproof switched spurs should do it.

 

[Plonker 3]

6A radial with weatherproof switched spurs should do it.

Good luck terminating 2x25mm SWAs into them

 

[rich spark]

Total is 12amp. But calcd 16amp in case of overload. Yeah all outside, how about how about the 25mm radial getting joint thru in an galv adaptable at each point and size down with a smaller cable to suply sockets?

 

[Guitarist]

Use 6x6 boxes for terminating swa, then short lengths of cable glanded into sockets (just make sure you continue armouring correctly). As already said, is there any reason it has to be 16 amp?
Good luck with the trench digging

 

[keniff]

Just out of curiosity, your allowed up to 11.5v drop? You could use 16mm swa 250m works out at 11.3v, or am I missing something here or doing the calc wrong

 

[Engineer54]

Are you sure your current draw is 12A? that seems a lot for just 4 cameras!!

 

[rich spark]

Cant remember exact gear, but think 4 cameras, 4 switches, and sum little bits that plug in. So id say 12amp prety much.

 

[telectrix]

i'd start by plugging all the camera gear in and measuring the current draw. then use that as your design current to calculate the volt drop.