pv array test - isc test

[paulsamuel1984]

Hi all,

What is the best method to safely test the short circuit current of a pv array. How do i physically have to do to carry out the test. I am sure our MCS assessor connected the positve and negative string cables of string together, before connecting into the inverter and used a clamp meter.

Is this safe to do with say 22 modules in a string?

Is there any other alternative methods?

 

[GaryM]

Yes it'll be safe as the modules are self limiting.
You could also make a set of leads with MC4/MC3 connectors and use the DC current setting on a multimeter.

 

[powervan]

Make test box up!!ask yellowvan man!!

 

[VMan]

I got one hell of an arc off 16 hyundai panels when disconnecting the string after an Isc test so now i have converted a dc isolator to switch the connections on/off when testing, with a couple of mc4 connectors.

 

[GreggElectrical]

I don't get why you would have an arc. You should connect or disconnect the PV cables under load.

Easiest way is to wire up the system as normal, Turn the DC isolator off, disconnect the PV cables from the inverter and plug together. Turn isolator on, take reading, turn isolator off and disconnect plugs. No arcing, no danger.

 

[Pwee]

I got one hell of an arc off 16 hyundai panels when disconnecting the string after an Isc test so now i have converted a dc isolator to switch the connections on/off when testing, with a couple of mc4 connectors.

Jeez! did you have to change your underpants!? :stuart: Seriously though, as said above, you need to turn the isolator off before shorting together. Unless you did the test before you'd taken the ends down to the isolator? It's a final commissioning test, all you need to test on installation is that each panel is producing similar voltages.

 

[VMan]

Jeez! did you have to change your underpants!? :stuart: Seriously though, as said above, you need to turn the isolator off before shorting together. Unless you did the test before you'd taken the ends down to the isolator? It's a final commissioning test, all you need to test on installation is that each panel is producing similar voltages.

The DC isolator was built into the inverter (and contractor wouldn't supply separate isolator) so i linked the panels together on the roof to check they were giving the expected readings...Live and learn .. i will always test through an isolator now