Advice on new Inverter

[whkdc]

I commisioned a 5kw system in 2003 using two SMA Sunnyboy 2500u inverters running 2 strings of 8 panels on each 2500u. (total 32 175w panels)

The SMA's have been rock solid from 2003 till now as One of the two stopped producing power. Strange thing, is that the unit shows no fault indicator. (shows as normal functioning on unit) All wiring, shutoffs/fuses and panels have been ruled out by swapping the strings from functioning inverter to faulty unit with same results.

I'm really looking for two things,

If I went to a TL inverter, probabably a 6k unit, would existing wiring suffice?

Does anyone have any experience with the Sunny Boy 2500u and this problem described? (i know this unit has been out of production for years)

Will

[sensij]

There are some differences in how the TL is wired. The DC system in the TL series is ungrounded (and *cannot* be grounded), while the 2500U was grounded, so you'd need to look at how the grounding was done and change the DC GEC to be an EGC only. Technically, that also means the wire colors should change... if white was used for the DC- to indicate that it was grounded, it should be changed to some other color suitable for an ungrounded conductor. You should also double check the voltage and current for each string and make sure they comply with what the TL requires, but that is probably ok, since the mpp range of the 2500u was 234-550V and that range should also be OK on the TL.