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Nissan LEAF30
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How will you get the internet connection there? A cat cable as well?
 

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Corsa-e 2020
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Cautionary tale... PodPoint installed my unit which needed a 70m run. Long story short... they used 10mm 2 core SWA and it wasn’t able to carry the volts at 32amp. They had to come back and replace the whole cable run with 16mm 2 core SWA.

They also installed data cable with it. About 35m of the cable is buried in ducting and the rest is clipped. Check the incoming voltage to your property. Mine is at the low end of the allowed tolerances at 223v which didn’t help.
 

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10.0 mm will carry a load of 30a/7kw for a max of 68mts so 50 mts should be fine..
Whoa this is an over simplification.
Get a voltage drop calc performed by a sparky for the ENTIRE SYSTEM. Also the cable burial details, soil conditions will have a small secondary effect. Who is responsible for designing the cable and the fault protection? Ask some searching questions.
 

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VW e-Up! 2020
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106 Posts
Soil conditions etc should only affect cooling/safety, not voltage drop?

100 m (50 out + 50 back) of 10 mm2 copper wire should have a resistance of 170 milli-Ohm, so at 30 A the voltage drop is 5.1 V and losses are 153 W. For 16 mm2 it's a 3.2 V drop and 96 W of losses. I've no idea what an acceptable voltage drop is and if this is too much or not.
 

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Soil conditions etc should only affect cooling/safety, not voltage drop?

100 m (50 out + 50 back) of 10 mm2 copper wire should have a resistance of 170 milli-Ohm, so at 30 A the voltage drop is 5.1 V and losses are 153 W. For 16 mm2 it's a 3.2 V drop and 96 W of losses. I've no idea what an acceptable voltage drop is and if this is too much or not.
9.6v.. and as the question was about the run of cable from the source to the charger as oposed to looped off another cable run.. not the whole system.. once again, adequate..
 

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Discussion Starter · #18 ·
9.6v.. and as the question was about the run of cable from the source to the charger as oposed to looped off another cable run.. not the whole system.. once again, adequate..
Yes, I wanted to confirm the run as the original company were still quoting for 6mm as they couldn’t do the job in the day due to restrictions and wanted to charge another £750 for the install.

Another electrician is the one who said I’d need 10mm SWA. Instead of clipping it all the way around the house it’s going to be hidden under the decorative stone chips.


Sent from my iPhone using Tapatalk
 

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The cable sizer on TLC says 6mm for 50m buried 3 course SWA, but the volt drop is near the limit. I'd definitely go up to 10mm unless you know your source voltage is marginal as b789 is.
 

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Soil conditions etc should only affect cooling/safety, not voltage drop?

100 m (50 out + 50 back) of 10 mm2 copper wire should have a resistance of 170 milli-Ohm, so at 30 A the voltage drop is 5.1 V and losses are 153 W. For 16 mm2 it's a 3.2 V drop and 96 W of losses. I've no idea what an acceptable voltage drop is and if this is too much or not.
From a technical point of view (i.e. notwithstanding anything that wiring regs say), the car's charger will usually be pretty tolerant of voltage drop, as it is likely to be designed for a wide range of supply voltages (e.g. my Kona OBC says 70-285V). Some EVSEs may complain at low voltages though.
Unless you do an awful lot of charging, the costs due to losses are going to be less than the cost of heavier cable.
e.g. if you do 10k miles./year, at 4 miles/kWh that's 2500kWh per year. At 15p/kWh that's £375 per year. The above drop figures for 10 vs, 16mm cable correspond to about 2% vs. 1.5% loss, so less than £2/year difference.
TLC prices show about £100 difference between 50m of 10mm vs. 16mm, so about 50 years to break even!
 
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