SMA Sunny Island 4248U, Инструкция по установке и эксплуатации

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SI4248U Manual Installation Manual
23
DC Input Circuit (Battery to Inverter)
WARNING:
The Sunny Island 4248U is designed to operate at a nominal voltage
of 48 V DC. Verify with a volt meter that the battery bank is wired correctly for
48 V DC prior to connecting the inverter.
NOTE: All electrical installation must be done in accordance with the local and
National Electrical Code ANSI/NFPA 70.
The maximum continuous DC current
of the Sunny Island 4248U is 100 A DC.
NOTE: The recommended length for the DC battery cables is <10 ft and should
not exceed 20 feet.
The Sunny Island 4248U comes equipped with a 175 A DC circuit breaker which allows for
improved transient surge capability. The battery conductors must be sized in accordance with
this circuit breaker and should be sized at 2/0 AWG (which has a rating of 175 A at 30 °C).
Paralleled smaller cables having a total ampacity of 175 A can also be used. For example,
two 1/0 AWG THHN conductors connected in parallel would have a total ampacity of 240 A
at 30 °C and four 1/0 AWG conductors will fit in1-1/2” trade size conduit (TSC). (Do not use
USE, XHHW or RHW insulated cables as they will exceed conduit fill ratings.)
For higher ambient operating temperatures, larger conductors may be required. The Sunny
Island 4248U will accept two 2/0 AWG conductors for both positive and negative DC inputs.
Refer to the NEC for more information.
If the batteries are located more than about 5 feet from the inverter or in another room, an
additional 175 A overcurrent device and disconnect should be located near the batteries.
Typical conductors for this application would be THHN or THWN-2 installed in conduit.
If the batteries are mounted on conductive racks or in metallic enclosures and/or there is a
metal enclosure for the battery disconnect/overcurrent device, then an equipment-grounding
conductor must be installed. For a 175 A overcurrent device, the equipment-grounding
conductor will be a 6 AWG bare, green-insulated or green marked copper conductor (see
NEC 250.122).
If the circuit conductors are oversized to compensate for voltage drop, the equipment-
grounding conductor must also be oversized (see NEC 250.122(B)).