Installation Guide

5. Verify that there are no unconnected wires.
6. If additional grounding wires need to be connected, use the equipment grounding
bus-bar. Tighten using a torque of 3.4 N*M / 30 lb-in.
Connecting the Strings to the Connection Unit
You can connect systems with multiple DC strings in parallel to the DC input terminals
of the Connection Unit. Inverters may have a different number of pairs of DC input
terminals, depending on the inverter power rating. If morestrings are required, they
can be connected in parallel using an external combiner box before connecting to the
Connection Unit. When connecting multiple strings, it is recommended to run separate
circuits to the Connection Unit or to position the combiner box near the Connection
Unit. This simplifies commissioning by allowing testing and servicing near the inverter.
NOTE
Use 16-6 AWG, 75-90°C copper wires only.
To connect the strings to the Connection Unit:
1. Equipment grounding: Connect the DC equipment ground conductor to the
equipment grounding terminal block in the Connection Unit.

NOTE
Functional Electrical Earthing of DC-side negative or positive is prohibited
because the inverter has no transformer. Equipment grounding of exposed
conductive surfaces in the array is required per the NEC.
2. Insert the DC conduit into the DC-side opening on the Connection Unit (left side at
the bottom of the Connection Unit).
3.
Connect the DC wires to the DC+ and DC- terminal blocks, according to the labels
on the terminals, connect two wires (DC+ and DC-) per string:
a. Use a standard flat-blade screwdriver to connect the wires to the spring-clamp
terminals. The screwdriver blade should fit freely in the terminal opening. Too
large a blade can crack the plastic housing.
b. Insert the screwdriver and firmly tilt it to press the release mechanism and open
the clamp.
c. Insert the wire into the top opening.
d. Remove the screwdriver – the wire is automatically clamped.
Chapter 5: Connecting the AC and the Strings to the Connection Unit 39
EV Charging Single Phase Inverter Guide MAN-01-00404-1.2