Sungrow SG30CX, User Manual

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• At an ambient temperature of 45 ℃ , the transformer can run in 1.1 times of load for long
time.
• A transformer with a short-circuit impedance 6% (permissible tolerance: ±10%) is
recommended.
• The voltage drop of system cable is no more than 3%.
• The DC component that the transformer can withstand is 1% of the fundamental current
at rated power.
• For thermal rating, the load curve of the transformer and environment conditions should
be taken into account.
• The apparent power of the inverter should never exceed the power of the transformer.
The maximum AC current of all inverters connected in parallel must be taken into ac-
count. It is recommended that the total number of inverters that are connected to the grid
not exceed 30.
• The transformer must be protected against overloading and short circuit.
• The transformer is an important part of grid-connected PV generation system. The fault
tolerance capacity of the transformer should be taken into account at all times. The fault
include: system short circuit, grounding fault, voltage drop, etc.
• Take ambient temperature, relative humidity, altitude, air quality, and other environmental
conditions into account when selecting and installing the transformer.
5.6.2 Requirements for OT/DT Terminal
OT/DT terminals (not included in the delivery scope) are required for fixing AC cables to the
terminal block. Purchase the OT/DT terminals according to the following requirements.
• Specification: M8;
• Dimensions: a≤30mm / 8.4mm≤b≤10.5mm / c≤16mm
5.6.3 Connection Procedure
High voltage may be present in inverter!
Ensure all cables are voltage-free before electrical connection.
Do not connect the AC circuit breaker until all inverter electrical connections are
completed.
step 1 Disconnect the AC-side circuit breaker and prevent it from inadvertent reconnection.
step 2 Take out the AC junction box and loosen the swivel nut. Remove the seals and select an ap-
propriate one according to cable outer diameter. Lead the cable through the swivel nut, seal,
and junction box successively.
5 Electrical Connection User Manual