Rating of 16mm Three Core SWA

[FozzieBear]

Please can someone advise the rating of three core 16mm swa when used as a single phase supply i.e. live, neutral and sleeved core as earth.

All the tables I can find refer to 16mm SWA as three phase being 94 amps clipped direct, 99 amp on cable tray or free air and 75 in ground or in ducting. Is this assuming all three phases carrying the same current? How do you rate the cable when only live and neutral carrying load. I am trying to work out what supply to run to an outbuilding on which will be installed 6kw solar and a 7Kw EV charger. the Solar batteries will be supplying house during certain Agile tariff periods and the gtod charging the batteries and possibly charging the car at others.
Install route is likely to be 18.5m direct burial and 5.5m direct clipped.
Many thanks

 

[EFLImpudence]

That's 90° cable.

70° is:

Would it not be the same as two-core? the CPC doesn't count.

 

[ericmark]

LSZH or PVC, the chart

is not the same for both, I would say however if two cores only used for power then 91 amp if installation includes Ref D. And at 90 amp right on the edge for volt drop.

However, the 6 kW and 7 kW are reverse direction. And looking at more like 32 amps, so 30 meter at 32 amp for 6 mm² what are you missing out?

 

[FozzieBear]

Thank you @EFLImpudence and @ericmark for responding. I am looking at XLPE/LSZH cable as that seem more available/affordable. This is for a "green" distribution board with only solar and charging. However we may want a second charger at some point and it seemed sensible not to skimp on the cost of running a larger SWA down the drive. The solar designer just mentioned about double checking the load carrying capacity before committing as the options in solar are beginning to advance such as using the car battery to power the house during a power cut etc.

 

[flameport]

I am looking at XLPE/LSZH cable as that seem more available/affordable.

That's fine, but the choice of material for the conductor insulation doesn't change the current capacity.
It will change the maximum operating temperature, but that's irrelevant in this case as the equipment it will be connected to most certainly will NOT be rated for 90C, and you wouldn't want that even if it was.

In any case, it's good for around 80 amps, which is far in excess of what a normal domestic property would use.
That's about 18kW, which is more than the supply to typical homes is rated for.

 

[FozzieBear]

That's fine, but the choice of material for the conductor insulation doesn't change the current capacity.
It will change the maximum operating temperature, but that's irrelevant in this case as the equipment it will be connected to most certainly will NOT be rated for 90C, and you wouldn't want that even if it was.

In any case, it's good for around 80 amps, which is far in excess of what a normal domestic property would use.
That's about 18kW, which is more than the supply to typical homes is rated for.

Thanks @flameport yes I think there is reference to this in the notes in Table 4E4A that you need to derate unless connected to 90c equipment (mcbs switchgear etc). I appreciate confirmation that this is adequate (probably in exces) for the application.