Cable running question

[Dairyspark]

Hi everyone,

I have the potential to be running a 185mm² or 240mm² 4 core SWA for a new supply for a silly farmer to fit 200kW of solar lol now my question is as follows, I know that I can calculate the size of Earth and if the armour meets the requirements, which I’m already thinking that it won’t, now if it doesn’t am I able to run a single core Earth in a duct alongside my mahoosive armour?

Also,I’ve set myself the challenge of calculating the cable size needed, haven’t done it since 2nd year of college so it’ll be interesting

Thanks
Bobby

 

[Fleeting]

Yes, strictly speaking it is a cpc.

 

[binky]

Sometimes it's easier to use smaller cables, but multiple cables to suit multiple 3 phase inverters bringing the power into a 3 phase board. That's how most of the solar farms are built.

 

[Dairyspark]

Sometimes it's easier to use smaller cables, but multiple cables to suit multiple 3 phase inverters bringing the power into a 3 phase board. That's how most of the solar farms are built.

I know but the issue is, Mr farmer is getting a new 400A supply and is determined to get it run into the barn where his existing supply is, but the solar is getting fitted to 2 sheds, one 80m away then a further 40m from there. Trying to convince him the get Scottish Power to bring the supply into the new shed where half the solar is going to be fitted, that was I only have to run one cable between the sheds and a supply back to feed his current set up

 

[binky]

I know but the issue is, Mr farmer is getting a new 400A supply and is determined to get it run into the barn where his existing supply is, but the solar is getting fitted to 2 sheds, one 80m away then a further 40m from there. Trying to convince him the get Scottish Power to bring the supply into the new shed where half the solar is going to be fitted, that was I only have to run one cable between the sheds and a supply back to feed his current set up

Sounds like a good idea to me.

Who's designing the solar array?

 

[Fleeting]

Parallel cables, two or three would probably be easier to install.

 

[Dairyspark]

Sounds like a good idea to me.

Who's designing the solar array?

The renewables company, they design and fit the panels and drop cables to ground level. Then they’ve got an electrical compan subbying to connect to all to the inverters and then AC out to an isolator and meter etc. and that’s as far as they go, we’ve got to then make it all work by feeding it back to supply point etc.

 

[binky]

The renewables company, they design and fit the panels and drop cables to ground level. Then they’ve got an electrical compan subbying to connect to all to the inverters and then AC out to an isolator and meter etc. and that’s as far as they go, we’ve got to then make it all work by feeding it back to supply point etc.

Sounds like you're stuck with a big cable then

 

[michael8554]

At which locations is the AC going to be used ?
Close to the "supply point" ?
Or to equipment in or around the sheds with the PV on ?

 

[Dairyspark]

Parallel cables, two or three would probably be easier to install.

i like this idea, so instead of one mammoth 240mm² I could run 2 x parallel 120mm2 or 3 x 95mm² (I know that’s more than 240)

 

[Dairyspark]

At which locations is the AC going to be used ?
Close to the "supply point" ?
Or to equipment in or around the sheds with the PV on ?

Closer to the supply point

 

[Fleeting]

i like this idea, so instead of one mammoth 240mm² I could run 2 x parallel 120mm2 or 3 x 95mm² (I know that’s more than 240)

No better than that. Using Table 4D4A for a buried cable and in the simplest terms using the maximum ccc for those cables you could get away with 2 × 70.0 or 3 × 35.0 but as I say that is a simplest view as you must consider vd and ADS.

 

[Dairyspark]

No better than that. Using Table 4D4A for a buried cable and in the simplest terms using the maximum ccc for those cables you could get away with 2 × 70.0 or 3 × 35.0 but as I say that is a simplest view as you must consider vd and ADS.

I’m liking this even more

 

[Sidewinder]

I’m liking this even more

A job like this needs a robust design. If it goes wrong it could be expensive.
I would strongly suggest that you sit down and create a formal design and calculations for the job and use it to drive your selection and erection.
Remember too, to use the correct rating and colour code for the isolators.
i.e. AC & DC sides have different kinds of requirements. Trouble is that nobody explains why.

 

[binky]

i.e. AC & DC sides have different kinds of requirements. Trouble is that nobody explains why.

if you do a proper solar course they do explain, but with so many DiY installations going on....

 

[Dairyspark]

A job like this needs a robust design. If it goes wrong it could be expensive.
I would strongly suggest that you sit down and create a formal design and calculations for the job and use it to drive your selection and erection.
Remember too, to use the correct rating and colour code for the isolators.
i.e. AC & DC sides have different kinds of requirements. Trouble is that nobody explains why.

We/I don’t get involved in the solar install, we provide means of connection in the form of a mccb panel board and mccb and the solar and their electrical subby does everything to there. The cable I’m trying to work out is to supply one of the sheds with a 400A supply from his proposed new intake point. However if we get our way the intake point will be moved to the shed so no calculation will be needed, or not as many lol