According to the ST XR Users guide they require 52-75VDC for full rated VA. Any idea what the effect is of dropping out of this range?

This may be important because the Sanyo HIT panels I'm planning on are 54Vmp but drop below 52V above 37C. Also I'm planning a roof install.

Thanks,
Sean

The Suntie will run down to just over 40 volts at 240 vac nominal , the software doesn't have any checks for 52 volts , so from that prospective it should be OK

I just read thru the Sanyo data sheet and did some quick math. On My Si array here in HOT lakeland florida , I'm seeing about a 45C rise above standard test condidtions , yup the array is at 70C ..

Plugging in the Sanyo numbers for derating , I come-up with a range of 45- 47 volts for vmp. This is pretty low , as long as the AC doesn't get near the high limit it will be fine , which is very unlikey to happen in hot conditions. The heat effects the utility wires as well.

Where is the array to be installed (zipcode) ?

91775

Average High 28-32C (Jun-Oct)
Record Highs 38-44C

But its a dry heat

I'm showing 86C as dropping below 44V. Including a .8v wiring drop (50' #10 @ 6.66A) leaving me at 80C for the 44V floor.

Might have to rethink the panel/inverter combination.

Sean

I think you missed one thing ,

The 45C rise includes the fact its 35C outside (95F) , so the Array is 35C over ambient plus the air is 10C warmer = 45C, I used the term standard condition (25C) for the baseline

LA doesn't get hotter Than Lakeland does it ? , I thnk my average numbers would match your worst case ones.