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M I G 3 0 0 M I C R O I N V E R T E R
I N S T A L L A T I O N M A N U A L
Grounding Options
Option 1: Integrated Grounding
Integrated grounding eliminates the need to install Grounding Electrode Conductor (GEC) to each MIG300
by completely isolating the internal DC circuit from the AC circuit and ground. DC ground faults are
detected on either the positive and/or negative conductors of the DC circuit by a Ground Fault Detection
Interrupter Insulation Monitor (GFDI IM). If the GFDI IM detects a ground fault has occurred to the PV
input, the micro inverter will automatically disconnect all conductors and cease supplying output power. In
accordance with NEC 690.35. Installers can build ungrounded arrays where only an Equipment Grounding
Conductor (EGC) is required to connect or bond non-current carrying metal equipment together. The EGC
grounding process is completed via the grounding connection of MIG300 4-wire AC cable to the AC trunk
cable. The PV module will still need to be grounded according to the module manufacturer’s instructions.
Option 2: GEC Grounding
Although the MIG300 offers integrated grounding (UL
1741 certified), it also comes with a grounding terminal
clip for any localities that do not accept integrated
grounding. Darfon will not be held responsible for
improper installations that do not have local AHJ and/or
Utility operational approval.
As indicated in the diagram below, the array GEC can be installed either in series or in parallel.