Jump to content

DONT STAY LURKING AS A GUEST,

JOIN TEF AND BENEFIT FROM MEMBERSHIP:

CLICK HERE TO JOIN.
g.bird

testing pv arrays

Recommended Posts

g.bird

hi guys i have solar pv on my roof,with a dc insulation fault, i suspect its due to water ingress.there are two strings,thats 2 pairs of wires going up to the pannels.iv  tested each pair with a multitester, having firstly disconected from the isolators and are geting the following .L=N  282V,L=E 204   ANDN=E 68V...THERE IS NO EARTH CONECTION TO THE PV ARRAY.for testing purposes iv used the earth connection of the main supply feeding the inverter/dc isolator,,,anybody got any ideas/help...on these findings..the system has shut down ,and will not resstart because of this fault...what is the cure.cheers

Share this post


Link to post
Share on other sites
ProDave

You are measuring voltage not insulation,. and the terms L, N and E are irelevant to the DC output from a string of panels.

 

You want to do an insulation test instead.

 

Best do it at night when the panels are not generating, get it wrong and 282V DC will HURT or worse, kill you.

Share this post


Link to post
Share on other sites
Andy™
53 minutes ago, ProDave said:

You want to do an insulation test instead.

 

IR test would confirm leakage, but given the voltage readinds and panel qty (not mentioned) you can easily work out which one has the fault. if it has 10 panels then its most likely panel 7 from the end with the highest reading to earth

Share this post


Link to post
Share on other sites
binky

there maybe no direct earh connection, but it will still register to earth through building structure. Seeing as you have 2 strings, disconnect 1 and see if fault clears, that eliminates 50% of array.

 

Share this post


Link to post
Share on other sites
g.bird

thankyou,,my system has 16 pannels,in 2 strings,,i was concearned about doing an insulation test using a 500v megger,because i understand the array on the roof has junction boxes with bypass diodes and was worried abt damageing them,or the pannels,,...question to binky,andy ,and prodave,cheers

Share this post


Link to post
Share on other sites
binky

They will take 500V test, some guidance videos below. 

 

 

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×

Important Information

Terms of UseWe have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.