Roofs and Cables


Cables can present an issue and should be addressed in the design stage of installing a solar system in a “Do it Yourself”  installation or in a professional solar installation.   The first consideration is DC (string) inverters or the older style, and AC (Micro) inverters or the newer style.  Both DC and AC have their place in helping the planet and everyone using renewable energy and sustainability methodologies. AC or Micro inverters have a far better safety capability.  

Any Cable installed and being connected into the distribution board must be connected by an electrician and provided a COC for safety and insurance, legally following NZ3000 wiring rules. Please keep in mind Solar Direct is not electricians nor do they wish to convey anyone should go beyond their capability  when installing solar, roof work, electrical work, or design and paper work.   The cable itself however can be installed by the home owner in a DIY install.  The more you can do reduces the hours billed by an electrician or solar installer.   AC, and DC solar cables have different rules to follow.  Familiarity with NZ5033, and NZ4777 as well as NZ3000 would serve well for the DIY solar installer as they are the regs you need to follow. 

For the most part any cable that has a manufacturers connector on it can be plug an play clickable and connected by a DIY installer.  Any cable that needs a connector has to be done by an electrician.  While there are some changes to the rules always and you should read the latest regs for yourself to make an informed decision, generally it is accepted that a manufacturers connector can be connected by anyone. 

DC solar cable must be run in clearly marked Solar conduit classed as UV retardant and heavy duty.  The mark has to be visible to the inspector and should read SOLAR HD T.   THe conduit must run from roof to inverter and the solar cable should have no breaks, and generally while some people use 4mm as a minimum size, we think it should be minimum 6mm.  The size of the cable however is determined by its length and the voltages and current running across them to prevent cable losses.   The more you try to save with cheaper cable the more it cost you in production over the next 30 years.   There are many, many videos on YouTube explaining how to install solar, and if you spend some time understanding things then you could save thousands by installing solar DIY.  It is pretty simple really, and everyone should be installing solar.  Lets not let the solar companies determine the pace of installation here in New Zealand,  everyone should do what they can as SOON as they can to get solar.  In theory we should have solar one every house in New Zealand by the end of 2020.  Imagine……..



There is absolutely no reason to pitch solar panels up in the air rather than laying them flat to the roof unless your roof is less than 8 degree pitch, maybe 5 in certain circumstnces.  Flat is better wind loading, cheaper,  safer, and performs almost as good as a perfect pitch of say 31 degrees.  the overall annual total is not significantly changed but more so the amount collected in varying times of the year.    For example,  1 kw of solar due north, and pitched at 31 degrees in Nelson lets say.  General rule is if you are not comfortable getting on the roof then dont try to install solar.  The roof is not a place to push your boundaries.  However you can save thousands on your solar system buying from us at Solar Direct and then get quotes to have a contractor install it, and an electrician to wire it.  Limiting the professional expensive time to only whats required, using less costing labour to do things you are simply not capable of is a great way to save heaps on a solar install. Suddenly, you take away any negative comments about return on the investment and we all can then focus on coming together and helping New Zealand to lead the way on saving the planet.    Again, I stress, safety is paramount.  If we all can do our bit however instead of waiting on the pace of solar installers and held to big package solar pricing then New Zealand can meet the goal of 100% solar by end of 2020.  Imagine…..Do it Your Self.