Table 2, Minimum Recommended Battery Cable Size Vs. Cable Length - Xantrex SW Series Owner's Manual

INSTALLATION
DC WIRING
CAUTION: The inverter's maximum peak current requirements are high. If battery cables are too
small and/or connections are loose, efficiency and maximum output power are degraded. Small
cables or loose connections may cause dangerous overheating and a fire.
BATTERY CABLE SIZING
The larger the battery cables the better. Undersized cables result in additional stress on the inverter, lower
efficiency, reduced surge power and lower peak output voltage. Don't use cables that are too small and
degrade the efficiency that we have worked so hard to achieve and you have paid so much to own.
Also, don't use cables that are too long - the shorter the better. The lower the DC system voltage, the
shorter the cables need to be. If long cables are required, either oversize them substantially, or switch to a
higher voltage system, such as 24 Vdc or 48 Vdc. On 12-Vdc system, cables may need to be doubled up
(paralleled) to get maximum performance from the inverter.
NOTE: Do not separate the positive and negative cables - taping them together in parallel is
best. This reduces the inductance of the wire resulting in a better waveform and reduces the
current in the inverter's filter capacitors. Make the battery cables as short as possible.
Although large cables may seem expensive, spending an additional $100 or more to ensure the
performance of your inverter is a wise investment. Using cables that are too small is like putting cheap
tires on a high performance sports car - the results will be disappointing.
If the system is expected to operate at the inverter's continuous power level rating for long periods of time
(over an hour), larger disconnects and cables may be required. Most systems do not operate at full
capacity for periods exceeding an hour and can operate satisfactorily with the following cable and
disconnects shown. If your system includes enormous batteries or has a very large DC source able to
continuously power the inverter (such as a hydroelectric plant, etc.) then increasing the disconnect and
cable sizes may be required to prevent nuisance tripping of a breaker or blowing of fuses.
The following table gives recommended minimum cable sizes for various cable run lengths and inverter
voltages. Use only all copper cables. These recommendations may not meet all local code or NEC
requirements.

Table 2, Minimum Recommended Battery Cable Size vs. Cable Length

TYPICAL
INVERTER
DC
MODEL
AMPS
SW2512 267 Amps
SW2612E 278 Amps
SW3024E or J 160 Amps
SW4024 or W, K 214 Amps
SW3048E or J 80 Amps
SW4048 or K 107 Amps
SW4548E or A 120 Amps
SW5548 147 Amps
1
TYPICAL DC AMPS is based on Low Battery Voltage with an efficiency of 85%.
2
NEC AMPS is based on Low Battery Voltage, an efficiency of 85%, and a 125% NEC de-rating.
WARNING! Battery cables that are too small will melt and burn the first time the inverter is
operated at high power levels.
2001 Xantrex Technology, Inc.
Page
5916 - 195th Street N. E.
22
Arlington, WA 98223
NEC 1 TO 3 FEET
2
AMPS ONE WAY
1
334 Amps #4/0 AWG/107 mm
348 Amps #4/0 AWG/107 mm
201 Amps #4/0 AWG/107 mm
267 Amps #4/0 AWG/107 mm
100 Amps #2/0 AWG/67.4 mm
134 Amps #2/0 AWG/67.4 mm
150 Amps #2/0 AWG/67.4 mm
184 Amps #4/0 AWG/107 mm
3 TO 5 FT
ONE WAY
2
#4/0 AWG/107 mm
2
#4/0 AWG/107 mm
2
#4/0 AWG/107 mm
2
#4/0 AWG/107 mm
2
#2/0 AWG/67.4 mm
2
#2/0 AWG/67.4 mm
2
#2/0 AWG/67.4 mm
2
#4/0 AWG/107 mm
Telephone: 360/435-8826
Fax: 360/435-2229
www.traceengineering.com
5 TO 10 FT
ONE WAY
2
Not Recommended
2
Not Recommended
2 2
#4/0 AWG/107 mm
2 2
#4/0 AWG/107 mm
2 2
#4/0 AWG/107 mm
2 2
#4/0 AWG/107 mm
2 2
#4/0 AWG/107 mm
2 2
#4/0 AWG/107 mm
SW Series Inverter/Charger
Part No. 2031-5
Rev. C: February 2001