Testing problems - please help

[WRDEnergy]

I am doing an install on a friends house which is identical to the one on my own house....

I have just finished putting all the panels up and wanted to test everything before I tidy up the cables... I tested each panel before I installed it just to make sure there was no problems.

I have run into an issue though... I tested the open circuit voltage on 8 panels (2 strings of 8) and got around 300 volts which is what I would have expect on a nice day like today... I then try to test the amp's so I short circuited everything and was only getting around 0.01 amps (basically nothing) when I would be expecting around 8 (ish)

I have checked all the connections and it seems strange to me that I am getting a voltage but no amp's perhaps someone has some idea's as to what I can do to find out the possible problem my mind has gone blank.

Thanks !

 

[prof. popkiss]

What kind of meter are you using to measure the current?

 

[yellowvanman]

How are you making the short circuit?

Like you I think if you've got a voltage you should get some current, so check the short circuit mechanism/procedure.

Did you check the voltage again after trying the short circuit? ie. voltage still good!

 

[WRDEnergy]

What kind of meter are you using to measure the current?

I am using a kewtech kt203

How are you making the short circuit?

Like you I think if you've got a voltage you should get some current, so check the short circuit mechanism/procedure.

Did you check the voltage again after trying the short circuit? ie. voltage still good!

yes I checked the voltage after and was still there. The meter I have does both amp's and volts have to use the clam for the amps I guess it is possible that part it broken.

To make the short circuit i am joining the + and - after the DC isolator it is the same meter I used on my course and I am 99% sure I am using it in the correct way. I also used this meter (although 5 days ago) to check each panel individual before I put them up on the roof (to try and avoid problems like this) and they where all fine....

any ideas would be appreciated

 

[yellowvanman]

Scaffolding still up, can you check one panel again? Just to make sure the clampmeter is working.

I assume you turn the dc isolator off, make a short ciruict (using what) and then turn the isolator back on. Best to go back to basics and work up from there.

 

[WRDEnergy]

Yeah the scaffolding is still here, I guess that's worth a try doing one panel and see if its working correctly.

and yes I do turn the isolator off make the the shirt circuit (using mc4 connectors) then turn it back on to measure it.

Thank you for your help I will let you know how I get on tomorrow if anyone else has been in a similar situation and found the issue please feel free to share !

 

[rb1]

I am using a kewtech kt203



yes I checked the voltage after and was still there. The meter I have does both amp's and volts have to use the clam for the amps I guess it is possible that part it broken.

To make the short circuit i am joining the + and - after the DC isolator it is the same meter I used on my course and I am 99% sure I am using it in the correct way. I also used this meter (although 5 days ago) to check each panel individual before I put them up on the roof (to try and avoid problems like this) and they where all fine....

any ideas would be appreciated

In response to yout meter we too have a Kewtech kt203 and had to return ours due to it being faulty so i'd try using another meter to see if your still getting the smae results

 

[gordysolar]

Did u try clamp meter other way it didnt say negative sign next to reading did it?

 

[morpheus75]

What is irradiance level? Voltage appears pretty much at any light level but current is light level dependent. Isc of panel times irradiance level divide by 1000 will give you expected reading


Sent from my iPhone using Tapatalk

 

[screwdriver]

Have you checked volts with isolator cover off? if so and you are now checking amps with the two ends coming out of the isoator have you considered a faulty isolator? we have had 2 in last few months.

 

[screwdriver]

bit dark to be doing it now obviously

 

[prof. popkiss]

You have a problem with either your meter or the circuit you're testing. It would be simplest to eliminate the meter first: a quick way to check this would be to clamp it around the earth lead from your car/van battery and switch the headlights on. You should obtain a reading of several amps.

 

[WRDEnergy]

ok so I have tried the meter on a single panel to test it and I am getting good voltage and amp readings so I think its safe to say at this point that the meter is fine.

Iradiance levels where fine I was getting around 700w/m2 at the time.

I guess it could be a faulty isolator but what are the chances of them both being faulty ? this morning I am not even getting a volate reading on either string. I guess it could be the isolator but whats the best way to check ? just a simple continuity check ?

I am now starting to think that:

1. maybe the isolator

2. maybe a cable problem

3. maybe a problem with the mc4 connections (although I checked these and they all looked fine)

anyone with any other ideas I will try and check the 3 I listed above.

 

[WRDEnergy]

If the only/best way to test an isolator is with a continuity tester (only thing I can think of) then the isolator is working how it should be..... this did however get me thinking.... could I not use a long lead from the end of the connection (i.e the bit just before the invertor) and to the furthest panel and use a continuity tester to see if I get a reading would that not let me know if there is a break in the connection somewhere and I can work my way back to find out exactly where the bad connection is (if there is one) or does using a continuity tester on solar panels mess them up in some way ? or not give you a reading altogether ?

 

[dansk]

Can you post the stats of the panel.