La Marche A31 - Making the DC Input Connections

5
2.2 Making the DC Input Connections
Before beginning any work inside the inverter, ensure that all incoming AC/DC power is de-energized and/or
isolated. Verify that no voltage is present inside the case by using a voltmeter at all input and output terminals.
Assure the inverter that is being used is the same number and type of cell as the inverter front nameplate
specifications. Select wire size using the table below. This is based on an overload current of 110-115% of the
input current listed on the inverter nameplate.
NOTE: Feeder breaker should be sized to match the size of the DC protection used in inverter.
Breaker Size/
Fuse Size (Amps)
Minimum Wire Size Requirement
for Customer Connection
Equipment Grounding
Conductor Minimum
3
#14
#14
5
#14
#14
10
#14
#14
15
#14
#14
20
#12
#12
25
#10
#12
30
#10
#10
40
#8
#10
50
#8
#10
60
#6
#10
70
#6
#8
80
#4
#8
90
#4
#8
100
#4
#8
125
#2
#6
150
#1
#6
175
#1/0
#6
200
#2/0
#6
250
#4/0
#4
300
250 MCM
#4
Table 4 – AC/DC & Ground Wire Size Minimum Requirements
(All wires specified in the table are rated at 90 °C or 194 °F)
NOTE: These are recommended sizes per La Marche Standards. The National Electrical Code (NEC) and Local
Wiring Codes must be followed.
DC Connection Procedure
Select proper size for the DC wires using the table above. If the distance between the inverter’s DC input and the
battery/load exceeds 10 feet, use the Power Wiring Guide in Appendix B to minimize the voltage drop across the
wire distance.
Make sure that the AC/DC breakers and the Inverter ON/OFF switch are OFF. Check polarity of DC input cables
and verify with multimeter. The positive battery wire should be connected to the POS terminal and the negative
battery wire should be connected to the NEG terminal.
NOTE: It is recommended to use a battery disconnect breaker between inverter and battery bank; helpful during
battery or inverter maintenance.