PVI 3000/4000/5000/5300
Installation and Operation Manual
50
Appendix D – Negative Grounding and Positive Grounding Option
Connection of the DC wiring
The wiring box of the PVI 3000-5300 inverter is designed with a pair of DC terminal blocks which support up to four (4)
independent PV strings to be connected in parallel in the wiring box and then feed into the inverter. The PVI 4000, 5000, and
5300 are shipped with up to four (4) 15A, 600Vdc PV string fuses for the PV strings. The PVI 3000 is shipped with three (3)
15A, 600Vdc PV string fuses, and therefore, the fourth pair of terminals (from left as shown in figure D1 are not be used to
connect to a PV string. However, the size of the PV string fuse shall be determined by the electrical ratings of the PV
module and by UL and National Electrical Code (NEC) requirements. Please refer to the section 5 for the replacement of the
PV string fuses.
There are two (2) terminals, labeled “Ungrounded (+)” and “Grounded (-)”, per PV string located in the wiring box used
for the DC connections. The DC equipment ground wire shall be connected to the screw of the ground bar labeled
in the
wiring box of the inverter. All the screws shall be tightened with a torque of 15.6 Lb-in (1.7Nm).
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11
Fig D1
PVI 4000 supports only four (4) PV string fuses (shown), the PVI 3000 supports only three
(3) PV string fuses (not shown).
The inverters supports both negative and positive ground for PV strings connections. The JP14 and JP15 jumpers are
used for the settings of the negative and positive grounding.
Connection of the DC wiring for Negative Grounded Systems
When the inverter is shipped with the negative ground setting, it is set as shown in the figure D2. The JP14 and JP15
jumpers are placed on the lower positions to set to the negative ground and the red Vdc wire is connected to Ungrounded,
DCIN+ terminal, the black Vdc wire is connected to Grounded, DCIN- terminal. In this case the positive polarity of the DC
input from the PV string shall be connected to Ungrounded (+) terminal and the negative polarity of the DC input from the
PV string shall be connected to Ungrounded (-) terminal as shown in the figure D3.