Xantrex Technology 1400i Marine Battery User Manual


 
10 Xantrex PROwatt™ SW International Sine Wave Inverter Owner’s Guide
Installation
Cabling Guidelines
Follow these guidelines and refer to Table 1 : Voltage Drop Per
Foot of DC Cable on page 10 to determine battery cable lengths.
Use 4 AWG copper (90 ºC insulation rating) as the smallest
battery cable size. This will minimize the voltage drop between
the battery and the inverter. If the cables cause an excessive
voltage drop, the inverter may shut down when drawing higher
currents because the voltage at the inverter input drops below
10.5 volts.
Keep all cables as short as possible, and ensure that each cable
between the inverter and the battery is no longer than 6 feet
(1.8 m).
Have all wires and cables terminated with correct and
appropriately-sized connectors and have the connectors
crimped at the place of purchase.
Do not use aluminum. It has about 1/3 more resistance than
copper cable of the same size, and it is difficult to make good,
low-resistance connections to aluminum wire.
NOTE: Xantrex recommends a size 0 cable with a maximum cable
length of 6 feet (1.8 m).
For example:
NOTE: Voltage Drop per foot = Current value × Resistance value
So for a 1000 W inverter output with a DC cable of size 0, multiply
the maximum current of 100 A with 0.000100. The result is 0.0100
voltage drop per feet. If the cable is 6 feet long, the total voltage
drop is 0.0100 × 6 = 0.0600.
So for a battery operating at 12.6 V at battery terminal the voltage at
the inverter terminal drops to 12.54 V.
Table 1
: Voltage Drop Per Foot of DC Cable
Inverter
Output (W) 500
1000 1500 2000
Current (A) 50
100 150 300
Wire
Size
(AWG)
Resistance
(ohms/ft)
@ 25 °C
Voltage Drop per Foot
4 0.000253 0.0127 0.0253 0.0380 0.0759
3 0.000201 0.0101
0.0201 0.0302 0.0603
2 0.000159 0.0080
0.0159 0.0239 0.0477
1 0.000126 0.0063
0.0126 0.0189 0.0378
0 0.000100 0.0050 0.0100 0.0150 0.0300
2/0 0.000079 0.0040
0.0079 0.0119 0.0237
3/0 0.000063 0.0032
0.0063 0.0095 0.0189
4/0 0.000050 0.0025
0.0050 0.0075 0.0150
PROWatt SW Inverter International.book Page 10 Tuesday, June 30, 2009 9:58 AM