Dc Wire Sizing; Table 2-2, Dc Wire/Overcurrent Device For Rated Use - Sensata Magnum Energy CSW3012-X Owner's Manual

2.4.1

DC Wire Sizing

It is important to use the correct sized DC wire to achieve maximum effi ciency
from the system and to reduce fi re hazards associated with overheating. Always
keep your wire runs as short as practical to prevent low voltage shutdowns
and to keep the DC breaker from nuisance tripping (or open fuses) because
of increased current draw. See Table 2-2 to select the minimum DC wire
size (and corresponding overcurrent device) required based on your inverter
model. The cable sizes listed in this table are required in order to reduce
stress on the inverter, minimize voltage drops, increase system effi ciency, and
ensure the inverter's ability to surge heavy loads.
If the distance from the inverter to the battery is >5 feet (1.5 m), the DC wire
will need to be increased. Longer cable distances aff ect the performance of the
inverter. See the lower part of Table 2-2 to determine the minimum DC wire
size needed for various distances greater than 5 feet—based on your inverter
model.
DC Wire Size Exception: In an OEM RV application, smaller DC wire (with
appropriate overcurrent protection) may be used if the inverter will only be
connected to a dedicated load, and the inverter and dedicated load have
been thoroughly tested and sold together by the OEM as a complete system.

Table 2-2, DC Wire/Overcurrent Device for Rated Use

Full Load Current
Maximum Continuous Current
Maximum DC Ground Wire Size
Minimum DC Wire Size
[90°C rating in free air]
Maximum DC Fuse Size
Increase size for
longer distance
Note 1 - Maximum Continuous Current is based on the inverter's continu-
ous power rating at the lowest input voltage with an inefficiency factor.
Note 2 - The grounding conductor for the DC system shall meet the
sizing requirements specified in the NEC for the application, but must
be no smaller than 8 AWG copper. In some applications (i.e., Marine
installations), the DC grounding conductor is required to be no less than
one size smaller than the wire size of the DC positive/negative cables.
© 2021 Sensata Technologies
1
2
Up to 5 feet =
5 to 10 feet = (2) #4/0 AWG (120 mm
2.0 Installation
282 amps
339 amps
#8 AWG (10 mm
#4/0 AWG (120 mm
[300 amps]
350 amps with time delay
#4/0 AWG (120 mm
)
2
)
2
)
2
)
2
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