Solar supply on test reports

Just to help others that may look at this post. I have been digging around in books and found some useful bits.

Guidance note 7, special locations chapter 10 Solar PV installations has some useful information

Practical guide to Inspection, testing and certification, 17th edition chapter 10 has similar content

Couldn't find anything significant in GN3

I would assume that IET code of practice for grid connected solar would be informative, so far have not purchased but probably need to.

Things I have picked up from reading the above and my thoughts

If the solar system isn't going to work in Island mode then the overall impact on testing is probably limited. If the system provides back up facilities with batteries and island mode operation system design and testing becomes significantly more complex.

Going back to the basic solar system without backup I don't think it's practical for standard EICR's to cover anything above the roof line due to access issues, I also suspect that companies installing and offering long guarantees will not want anyone going near their system anyway. maybe some companies will claim they can check thigs from a ladder with cameras on a pole or something but I don't see how structural and electrical integrity can be checked without giving things a good push and pull, plus moving cables to check for abrasion issues and cracking.

Providing that the input and output of the inverter have been isolated performing standard insulation and R1+R2 tests to the isolator switch is fairly straight forward. I personally would be very nervous about doing insulation tests unless i was sure that I could isolate the expensive inverters and panels from the test. I think if I was doing the test I would want to measure open circuit voltage and short circuit current of the panels before and afterwards so that I have a record if someone tries to claim I damaged one of their panels.

It appears most legacy systems will have the inverter as near to the panels as possible as rules for DC cable runs through houses are more onerous.

Inspection of the accessible AC and DC wiring should also be fairly straight forward.

It's probably not to difficult to test the DC wiring up to the 1st isolator in the system so that the panels are isolated from the test.

If changing a distribution board where the solar is connected and an RCBO is required the RCBO needs to be bi directional and may need to be type B depending on how well the inverter isolates the AC output from the DC supply.

For TNCS unless the panels are class 2 the mounting frame should not be connected to the suppliers earth facility but to an earth rod, I don't know but my guess is that most panels will be class 2 to overcome this.

When looking at the newer systems with battery walls and backup things change significantly

Much more difficult to fully isolate the system

For best efficiency the battery and solar will be DC coupled with a shared inverter driving longer DC cable runs through the property with more onerous rules for cable protection

In island mode the backup system will need it's own TT earth which will need testing

I feel like I am beginning to understand more about these systems and realise how much I don't know.

Just to help others that may look at this post. I have been digging around in books and found some useful bits.

Guidance note 7, special locations chapter 10 Solar PV installations has some useful information

Practical guide to Inspection, testing and certification, 17th edition chapter 10 has similar content

Couldn't find anything significant in GN3

I would assume that IET code of practice for grid connected solar would be informative, so far have not purchased but probably need to.

Things I have picked up from reading the above and my thoughts

If the solar system isn't going to work in Island mode then the overall impact on testing is probably limited. If the system provides back up facilities with batteries and island mode operation system design and testing becomes significantly more complex.

Going back to the basic solar system without backup I don't think it's practical for standard EICR's to cover anything above the roof line due to access issues, I also suspect that companies installing and offering long guarantees will not want anyone going near their system anyway. maybe some companies will claim they can check thigs from a ladder with cameras on a pole or something but I don't see how structural and electrical integrity can be checked without giving things a good push and pull, plus moving cables to check for abrasion issues and cracking.

Providing that the input and output of the inverter have been isolated performing standard insulation and R1+R2 tests to the isolator switch is fairly straight forward. I personally would be very nervous about doing insulation tests unless i was sure that I could isolate the expensive inverters and panels from the test. I think if I was doing the test I would want to measure open circuit voltage and short circuit current of the panels before and afterwards so that I have a record if someone tries to claim I damaged one of their panels.

It appears most legacy systems will have the inverter as near to the panels as possible as rules for DC cable runs through houses are more onerous.

Inspection of the accessible AC and DC wiring should also be fairly straight forward.

It's probably not to difficult to test the DC wiring up to the 1st isolator in the system so that the panels are isolated from the test.

If changing a distribution board where the solar is connected and an RCBO is required the RCBO needs to be bi directional and may need to be type B depending on how well the inverter isolates the AC output from the DC supply.

For TNCS unless the panels are class 2 the mounting frame should not be connected to the suppliers earth facility but to an earth rod, I don't know but my guess is that most panels will be class 2 to overcome this.

When looking at the newer systems with battery walls and backup things change significantly

Much more difficult to fully isolate the system

For best efficiency the battery and solar will be DC coupled with a shared inverter driving longer DC cable runs through the property with more onerous rules for cable protection

In island mode the backup system will need it's own TT earth which will need testing

I feel like I am beginning to understand more about these systems and realise how much I don't know.

Alan B said:

Guidance note 7, special locations chapter 10 Solar PV installations has some useful information

Practical guide to Inspection, testing and certification, 17th edition chapter 10 has similar content

Couldn't find anything significant in GN3

I would assume that IET code of practice for grid connected solar would be informative, so far have not purchased but probably need to.

There is also an IET Code of Practice for Electrical Energy Storage Systems for the battery side of things.