Outback Power Systems PV Ground-Fault Detector Interrupter (GFDI) Installation - Manual (Page 4)

3
FUNCTION
The GFDI consists of a single 0.5 amp breaker, mechanically
connected to a combination of 1, 2, or 4 standard OutBack 80 amp
breakers (see list on previous page).
• When a ground fault occurs, the 0.5 amp breaker will trip. Due to the
common internal tripping mechanism, all the other breakers connected
to the GFDI will also trip and shut power down.
• All power production from PV array charge controllers ceases when
the breakers trip and remove their connection to the batteries.
Standards and Requirements
Code Requirements
All installations must comply with national and local electrical codes;
professional installation is recommended. NEC requires ground fault
protection for residential PV installations. For more information, see NEC
690.5.
DC and Battery-Related Installation Requirements
• Shut off all DC breakers before connecting any wiring.
• All wiring must be copper and rated at 75° C or higher.
• Use a minimum cable size of #3 AWG* for 80 amp breakers and
#14 AWG for 0.5 amp breakers (NEC table 310.16).
• Torque breaker nuts to 35 inch-pounds/4.0Nm.
For installations above 30 degrees C, follow the correction factors at the
bottom of NEC table 310.16 using 100 amps as the base line.
In addition:
• The GFDI is only to be used with OutBack UL 1741 or UL
508A listed photovoltaic based products.
• The GFDI shall be the only bonding connection between
grounding system and battery negative in the DC system.
• The GFDI is not intended for use in positive ground installations.
*UL174116.1.3 states: A wiring terminal or lead shall be rated and sized for
connection to a field wiring conductor having an ampacity, based on Table
310.16 of the NEC, of no less than 125 percent of the RMS or dc current that the
circuit carries during rated conditions. 80 amps X 1.25 = 100 amps, which
requires #3 AWG wire (in ambient conditions of no more than 30 degrees C).