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Residential:
Vendor: Citel, Part Number DS72RS-120 or DS73RS-120
Application: DS72RS-120 is applied when N-G is bound together, or DS73RS-120 were N-G is unbound.
Commercial:
Vendor: Citel, Part Number SP-120
Application: Branch panel protection
See the vendor datasheet for DS70R, (which includes the DS72RS-120) or for SP-120 at
www.citelprotection.com/english/citel_data_sheets/ac_protection/
Integrated Grounding
UBIQUITI SM-MI-250 offers Integrated Grounding, which eliminates the need to install a Grounding Electrode
Conductor (GEC) to each micro inverter 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 SM-MI-250 4-wire AC cable to the AC trunk
cable. Despite the fact that UBIQUITI has made it easier for the SM-MI-250 to install, by integrating the ground to
the AC trunk cable, the PV module will still need to be grounded according to the PV manufacturer’s recommended
grounding methods.
