AE 3TL-16 Inverter Replacements

[Janthony@max-solar]

I have a site with 6 AE 3TL-16 Inverters that is looking to be re-powered. The current inverter has 10 strings coming in and it was recommended to replace them with Solis inverters but the Solis inverter recommended only has a 6 string input and the input voltages do not match up. I'd like to not have to re-string the site to come up to the 1000VDC input requirement. The AE is setup for a 500VDC input. Does anyone have some recommendations for possible replacements?

 

[pv_n00b]

There are no drop in replacements for older inverters. There is always going to be some rework to do in a repower if you want to reuse the array. The Solis might be the best you can find. Don't look at the maximum DC voltage input, look at the MPPT range. You want a range that is low enough to work with your string voltage. The Solis has a 180-1000V MPPT range that might be the best you can get in a small 480V 3ph inverter. The problem with the inputs is going to be that for the older inverters they had lots of inputs for lower voltage strings. Newer inverters have fewer inputs of higher voltage strings. No way around it. Your best bet is to find an inverter that will allow you to combine externally and the just land a single circuit.

 

[Zee]

Maybe combine 2 strings into 1? So 10 combined to 5 strings per INV.

Bear in mind you might combine the strings in series or parallel:

SERIES - If you calc the Max VDC (cold temp VOC) for 2 strings in series to be under 1000 VDC, you could go in series.
PARALLEL - The existing panels may not support 1000 VDC (over 600VDC) strings....so then maybe in parallel, especially if the Amps are low enough.

I have no clue about those inverters though, I just have played with rewiring many old systems.

It always requires either a transformer on the AC side, rewiring strings, and/or adding a combiner box.

 

[ggunn]

Maybe combine 2 strings into 1? So 10 combined to 5 strings per INV.

Bear in mind you might combine the strings in series or parallel:

SERIES - If you calc the Max VDC (cold temp VOC) for 2 strings in series to be under 1000 VDC, you could go in series.
PARALLEL - The existing panels may not support 1000 VDC (over 600VDC) strings....so then maybe in parallel, especially if the Amps are low enough.

I have no clue about those inverters though, I just have played with rewiring many old systems.

It always requires either a transformer on the AC side, rewiring strings, and/or adding a combiner box.

He may be able to leave it strung at 500VDC; many 1000VDC inverters will run fine at 500VDC. Combining strings in parallel could be problematic; the combined Isc of two strings might bust the input current limit on the MPPT inputs.