Enphase IQ7X-96 micro inverter application

Davtherav1
Davtherav1 Registered Users Posts: 1
I have a large number of REC 235 PV panels and after looking at the specs for the IQ7X-96, I realized that two of my panels wired in series would meet the spec for one IQ7X-96. Any concerns you would have about an installation of this sort?? Cost savings would be significant if one inverter would service two smaller PV panels. thanks, dave

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Looking at the IQ7 and REC 235 specifications... It appears that you could have issues in cold weather (you are in Colorado).

    http://www.solardesigntool.com/components/module-panel-solar/REC-Solar/541/REC230-PE-US/specification-data-sheet.html
    https://enphase.com/sites/default/files/downloads/support/IQ7X-DS-EN-US.pdf

    So, you need to know the minimum temperature for your location, and see what the Voc-array-cold maximum would be. Two of your panels in sereis could exceed the 79.5 VDC max input voltage (in sub freezing temperatures?).

    The IQ7 is designed for 96 Cell panels... Your two panels in series would be 60+60=120 cells.

    Also, there is always the question of how you will be monitoring your panels/arrays. Will you get an Enphase monitoring box too (wireless networking) so you can keep track of how everything will work?

    Using a string sizing tool from Midnite Solar:

    http://www.midnitesolar.com/sizingTool/index.php

    PV Array
    Rated PV Array Power:460Watts
    Anticipated Array Power @ 95F:439Watts
    Rated PV Array Current:7.8Amps
    Battery Charging Current @ 57.6 V:8Amps
    VMP (Maximum Power Point Voltage) :58.8Volts
    VOC (Open Circuit Voltage):74.2Volts
    VMP @ 0 F°:70.2Volts
    VOC @ 0 F°:84.6Volts
    Classic, Classic SL & Classic Lite Charge Controller Selection
    150200250
    Max Operating Voltage150200250
    Max Non operating VOC (HyperVOC) @ 48V Nominal Battery Voltage198248298
    Maximum Number Of Modules In Series345
    Max Number Of Modules In Series (Using HyperVOC)457
    Max Allowable Output Current Per Classic
    Based On This Current Configuration
    867855
    Max Allowable Wattage Per Classic
    Based On This Current Configuration
    502245503212
    Present PV Array Wattage Of This Configuration460460460
    Design Check
    Max VOCOKOKOK
    Temperature The Classic Will
    Enter HyperVOC
    -481 F°-848.2 F°-1215.4 F°
    Array Power (Wattage)OKOKOK
    Classics Required0.10.20.2

    Voc-cold would be ~84.6 VDC at 0F (guessing your cold weather minimum temperature) and exceed the IQ7 79.5 volt max.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset