little worried

[sime27]

if 2 panels in a array of 10 was connected the wrong way round after making an extention past a dorma window would i still get a VOC reading ? or wound i get 0 volts ?
am worried roofer put 2 neg ends on the extention

 

[edexlab]

You might get a reading but it would be a figure minus the two panels, this happened to me a while ago apprentice did it because the roofer had wired the modules incorrectly and there was 2 male ends the roofer told him it would'nt make any difference if he changed one to a female
lesson learnt : never listen to a roofer unless its about roofs

ie if each panel is 50v you should have a reading of approx 500v voc for the array
if he has put 2 neg connectors it will be minus the number of modules on the extension
ie 2 modules less equals 100v less than the expected voc which would be 400v

 

[sime27]

heres what i think he did
+ from inverter to 1st panel then round the 8 panels as normal so the last panel had a - hanging out he then made up an extention lead across dorma and conected - to - between 8th and 9th panel then 9th and 10th panel conected together leaving a + hanging out of the 10th panel which went back to the inverter which makes the last 2 panels wrong way round . I've got to commission the job tomorrow but scoffold been removed today . What reading will i get on Voc if what am saying above is correct? before i power inverter up ?

 

[Worcester]

ie if each panel is 50v you should have a reading of approx 500v voc for the array
if he has put 2 neg connectors it will be minus the number of modules on the extension
ie 2 modules less equals 100v less than the expected voc which would be 400v

Not quite, remove two panels and the Voc will go down by 2 x 50V to 400V
put them in the wrong way round and you have to deduct 2 x 50 V AGAIN

Think of them like battery cells or AA batteries, Take 2 AA batteries 2 = 3V , 1 missing = 1.5V, 1 the wrong way round = 0V

so

ie if each panel is 50V you should have a reading of approx 500V Voc for the array

if he has put 2 neg connectors it will be minus the number of modules on the extension

ie 2 modules less equals 100V less than the expected voc which would be 400V
and 2 mondules the wrong way round equals 200V less than the expected Voc which would be 300V