what tests do i need to do on the pv system

[stubo300]

tomorrow i am installing my first pv panels, i already have the mounting system up,

my question is.

what tests do i need to do on the panels when they are not fitted, and how do i carry them out and what results do i need to record.

what tests do i need to do once the panels are mounted and wired in

etc etc many thanks

 

[yellowvanman]

Before you take the panels up onto the roof you need to check Voc with cables open circuit and Isc with cables short circuited - need to use a clamp meter (with dc) and they usually have a voltage option as well. Need to measure irradiance and make sure the Isc is in the 'ballpark' of expectations and Voc is as expected. No need to record any info on this - just need to make sure panels are Ok before you fix them in.
Once all panels are up and connected you then need to measure the string(s):
Voc
Isc with solar irradiance
Check Polarity
earth continuity (if applicable)
Insulation resistance
This data needs to be logged in a PV Array Test Report, to be included with your Electrical Installation certificate and handed over to the customer at the end (with other documents).

 

[stubo300]

That is spot on thank u.
When I do a insulation resistance test do I do that once I have all the pv panels connected in seris. And test at the dc isolator.

And when I short circuit each panel. Do I need to do that once all the panels are connected or is that dangerous

 

[yellowvanman]

Probably a bit late for you to use this reponse, but here goes anyway.

Regarding insulation test - yes.

You need to do an Isc test for the string. The current will only be as high as the 'worst' panel, but I would recommend getting a 'test box' so that you don't have to 'hot disconnect' plug/sockets. Whilst current may not be high, dc voltage will probably be - but plug/sockets are pretty safe for handling, just need to be wary when probing.

 

[stubo300]

thanks again

i have installed 2 strings of 10 x 190 watt panels, so after the dc isolator which is turned of i connect the 2 ends of the strings together (positive to negative), i then turn the dc isolator on and test the Isc with a clamp on meter, is that correct and that wont damage any of the panels.

also do insulation resistance test not damage the panels

 

[yellowvanman]

Correct - should be fine! You've already done an Isc on the indivdual panels, so doing an Isc for the string won't stress it any more! Also correlate the Isc measurement with the irradiance level. You also need to measure Voc for the strings.

 

[goodwilld]

Scary----get some qualifications on PV.

 

[Von Vardo]

Really wouldn't do an insulation resistance on the panels unless I had deep pockets.

 

[stubo300]

I did the course a few months ago and the course was not great. So I need some advise for peace of mind.

 

[yellowvanman]

Part of the requirements for a PV Array Test Report is to do an insulation test as per Appendix C of the 'DTI guide to installing PV systems', which is a downloadable document.

 

[dansk]

Most panels can take upto 1000v -

 

[goodwilld]

stubo300
send me your email addy and i will send you some stuuf to make life a little easier for ya.

 

[Pittsy9]

Hi any chance you can forward me some information on pv testing. Thanks matthew [email protected]

 

[snowywhite]

Hi goodwill can forward me some information on pv testing. cheers paul [email protected]

 

[1billy wiz]

hi stubbo i know where you are coming from with unincitefull courses.if your a sparks the ac side requires know explaining. as for the dc you take an open circuit test & check polarity at the same time as your meter will show the negative sighn - then close plugs & clamp the meter for your amp reading. also mate you can plug in panels on load. but never unplug them as you could damage them. i think by looking at a schematic shows how easy the install operation is.obviously surveying & accounting wind &snow loads & shading issues are another thing to insure system efficiency.