200m Single Phase 16mm Cable running underground

[Msholozi]

Must the cable run inside the conduit or not?
The cable is 16mm 3 Core unarmoured

Thanks.

 

[Voicy]

You're not allowed to run unarmored AC cable underground without proper ducting. If a gardnerer chops it with a spade and dies you're getting the book thrown at you.

Even armored cable comes with a chapter of safety protocols including depth, anti-pick tiles and warning tape at different heights.

 

[Msholozi]

Thanks for the response.

So should I use PVC or steel conduit?

 

[Voicy]

Just keep in mind that anything over 50m, you're not too bothered with the ampere capacity of the cable as much as you'll be concerned with the voltage drop.

200m will get you over 10% volt drop due to internal resistance.

 

[MrSnyders]

According to wiring code:
If buried less than 0.5 m below, it needs to be in a conduit, otherwise mechanically protected (paving or concrete slab), or protected by earth leakage with 30 mA or smaller rating.
If buried at least 0.5 m below, the backfill has to be clear of sharp objects and you need to place marker tape the full length of the cable at 0.3-0.4 m below the surface.

You are only allowed a 5% voltage drop, so on single phase (240 V) that will be 12 V. On a 16 mm² cable over 200m, that means a maximum current of 21.4 A (using 2.8 mV/A/m voltage drop).

 

[Msholozi]

Thanks for the info. But my question hasn't been answered yet. Should I use PVC or steel to cover my cable?

 

[MrSnyders]

I think that, as regulations only refer to 'a conduit', it can be either PVC or metal.

 

[thehuman]

Does the regulations state you may use un armoured cable ?