Trouble shooting 10Kw system.

[grdelectrical]

We are in the process of installing and commisioning a 10Kw system on a council building. We have two strings of 20 modules.
When we tested the strings we were getting 694 and 692 Volts and 5.8 amps - clear sunny day - all looked good.
However, during the afternoon one of the strings managed to burn out its DC isolater? We disconnected the load and checked the connections etc, all seemed ok - so we assumed a faulty DC switch. But, when we reconnected after about an hour it did the same?

Any thoughts?

Cheers.

 

[pjcomp]

Are the solators rated for that level of throughput? Perhaps the "faulty" one is the one which didn't burn out?

PJ

 

[Eco Chap]

Are the solators rated for that level of throughput? Perhaps the "faulty" one is the one which didn't burn out?

PJ

Agreed, check the voltage limits for the Isolator, If I recall the kraus & naimer brand we often use have a larger model for over 600V.

 

[LightGEN]

Also, bare in mind that, for DC use, the switch may require that the terminals are doubled up, by which I mean that, where the switch has four sets of terminals, two sets of contacts should be used to switch the positive supply and two to switch the negative supply, this being achieved by using short jumper cables to bring the second sets of contacts into service.

 

[Glen Powell]

There are only a few TRUE DC isolators on the market all the others are modified AC, if it not a Santon or IMO then that could be the reason why, Buy cheap, Buy Twice.