PVI 1800/PVI 2500
Installation and Operation Manual
17
Suggested AC Disconnect: 240V AC, 30A, 2 Blade, NEMA 3R
Part Number Manufacturer
Rain-proof NEMA 3R, no fuse
DU22IRB
Square D
Rain -proof NEMA 3R, fusible
Rain-proof NEMA 3R, no fuse
TG3221R
TGN3321R
GE
GE
Pull-out disconnect, 3R, no fuse
3800
Millbank
For some installations, code compliance may include indoor, NEMA 1 rated disconnects which are less
expensive. For whichever disconnect is selected, you will also need the proper listed ground bar kit. (No
neutral kit is needed, as no neutral line should enter the disconnect.)
Connecting the AC Inverter Wire:
WARNING:
The wiring of the PV inverter’s AC and DC wires must only be done with the
building AC circuit breaker off and the PV array disconnected or covered with an opaque
material (or other method to assure the PV wiring is not live). Both AC and DC disconnects
should be off.
If the connection of the AC wires that are provided on the inverter is to be made to an AC disconnect or
junction box, mount the disconnect or junction box. (Make sure the disconnect or junction box is close
enough to the inverter so that the inverter wires will reach the disconnect or junction box via a conduit
and so that an adequate length of wire will be available inside disconnect or junction box to make the
connections/terminations to the L1, L2 and ground point.) As shipped, the conduit fittings included on
the inverter have the wires but no conduit in them. The conduit is to be fitte d during installation.
Measure and cut the 1/2” liquid-tight metallic or non-metallic flexible conduit to connect between the
inverter’s AC conduit fitting and the disconnect or junction box. Next, install conduit fitting on the
disconnect or junction box. Thread the inverter’s AC wires through conduit and into disconnect or
junction box conduit fitting. Fit the conduit into the conduit fittings on inverter and disconnect or
junction box and tighten. If needed, cut off the inverter AC wires to correct length(s) inside the
disconnect or junction box. Finally, terminate inverter wires in disconnect or junction box. Black wires
are L1 and L2. Green is the AC equipment ground.
Connection Wiring To Electrical Utility Grid And Grid Impedance:
The PVI 1800/PVI 2500 must be connected to the grid with 2 conductors and a ground wire.
The grid impedance value at the connection point should be as low as possible to avoid an increase of the
AC-voltage to non-permissible values while the inverter feeds to the grid. Minimizing wiring impedance
also results in higher system efficiency.
EXAMPLE:
The impedance is the sum of the electricity grid impedance at building
distribution and all impedance values of conductors and connections.
Single conductor impedanc e values are:
