# Forum Home Renovation Solar Electrical Systems  Solar Panel Cable

## PlasterPro

Hi guys 
We are doing a reno and at some point in the future may want to install solar panels for electricity. But while the plaster is off I am thinking I will run the cable fron the roof to the power board? 
Just wondering what sort of cable is required? 
and to the fuse box inside or the power board outside?
Thanks in advance 
Marty  :Biggrin:

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## applied

It depends on the brand and the size of the instalation as it is dc power and it actually runs to the inverter your probably better off installing empty conduit because we use uv rated single strand cables that are purpose built also depending how many pannels you get you may need two four or six runs. You cannot run dc into your switchboard unprotected. Plus you won't recover the cost of the cable from the installer.

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## NigeC

> It depends on the brand and the size of the instalation as it is dc power and it actually runs to the inverter your probably better off installing empty conduit because we use uv rated single strand cables that are purpose built also depending how many pannels you get you may need two four or six runs. You cannot run dc into your switchboard unprotected. Plus you won't recover the cost of the cable from the installer.

  That's some good advice. Put a 25mm conduit in with a draw wire.

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## Moondog55

May be easier to use something bigger than 25mm, too late  change after the plaster is back up, but running a pull wire thru is a great idea

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## PlasterPro

good advice there will run a conduit
just to clarify run it to the metre board outside?

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## applied

Assuming you have an accesible roof space run it from some convient place above the switch board down the wall to a spot next to the switchboard probably about 600mm to the side. The inverter is about the size of a large shoebox so keep that in mind when positioning it. You will also need a conduit from the inverter to the switchboard. This is where it gets a bit more involved because you would have to drill a hole in the top of a live switchboard box then fix the conduit in place with saddels or simmilar and use glands to attach to top of the board. You cannot just leave empty conduits hanging out the top so you would need to seal it to prevent fire. If you have single story cavity walls your realy not saving yourself anything because a installer will be able drop between the walls by lifting the roofing sheets or tiles. This probably isn't what you were hoping for but that's the way it is

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## PlasterPro

> Assuming you have an accesible roof space run it from some convient place above the switch board down the wall to a spot next to the switchboard probably about 600mm to the side. The inverter is about the size of a large shoebox so keep that in mind when positioning it. You will also need a conduit from the inverter to the switchboard. This is where it gets a bit more involved because you would have to drill a hole in the top of a live switchboard box then fix the conduit in place with saddels or simmilar and use glands to attach to top of the board. You cannot just leave empty conduits hanging out the top so you would need to seal it to prevent fire. If you have single story cavity walls your realy not saving yourself anything because a installer will be able drop between the walls by lifting the roofing sheets or tiles. This probably isn't what you were hoping for but that's the way it is

  solid brick walls with a real Biatch of a run to get cables from the new extension to the front of the house (switchboard) that is solid brick  :Rolleyes:

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## applied

If your  best option is conduit just use what you now know run from the ceiling space near the roof that will take the system to near not in the board this will save them time and will probably look better. If you don't feel confident running into the board your installer will be able too otherwise They will just surface mount the last bit solar pannels also install great on shed roofs especially when your frontage is north and you don't want to see them.

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## Bloss

As 'applied' says Conduit is the go but just where later access will be difficult - as you described. Not really much to be saved otherwise. Trying to guess cable types, lengths etc is fruitless. Inverters come in all shapes and sizes not just 'a large shoebox' - depends on brand, model & designed capacity too. 
Can't see why you'd skimp on the conduit size as already mention - use larger (say 40mm) as spare space in the conduit is not a problem. Not enough means you've wasted your time & effort. If you need to use bends then use a good wide radius as the cables from the panels will not like tight radius bends.

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## NigeC

> May be easier to use something bigger than 25mm, too late  change after the plaster is back up, but running a pull wire thru is a great idea

  Put two in then!!

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## Bloss

> Put two in then!!

   :What he said:  that'd work of course and usually easier to pull through a later one than getting drag on an existing cable.  :2thumbsup:

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## applied

You also have one other option all the suggestions so far have assumed you will install the inverter near the switchboard however this is not always the way it is done. It would be possible for you to run a 2.5mm cable from the switchboard down to your extension and just mount a outdoor gpo where you want the inverter to go in the future for example in a lane or if you want to show your guests how green you are( don't laught this Is common) on your patio. Then when the system is installed just replace the gpo for the solar isolator. Then you get something for you effort in the short Time. This will definately save the installer a lot of hassles later

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## NigeC

> You also have one other option all the suggestions so far have assumed you will install the inverter near the switchboard however this is not always the way it is done. It would be possible for you to run a 2.5mm cable from the switchboard down to your extension and just mount a outdoor gpo where you want the inverter to go in the future for example in a lane or if you want to show your guests how green you are( don't laught this Is common) on your patio. Then when the system is installed just replace the gpo for the solar isolator. Then you get something for you effort in the short Time. This will definately save the installer a lot of hassles later

  good advice

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## Bloss

:Wat they said:  but . . . the placement of the inverter is best left to the system designer & installer so unless you have already discussed the system and location with your intended supplier (and I recall you haven't) then I'd stick with the conduit right now. For example although the general rule is the inverter should be as close to panels & switchboard all that is really critical is that the cables allow no more than the specified voltage loss on the DC (panel) side - usually <1%. On the output side the regular 2.5mm power cable will be fine. 
The inverter is best on the south side or in shade - even under the house or in a garage (if that gives even temperature and is cooler). Cooler they are better they run (put crudely) - above -25 or so! Mine is under my laundry for example. Of course you have to get a remote monitor system unless you want to go under the houses to see what is happening, but I reckon the indoor monitors are a good idea anyway.

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