Sungrow SG350HX-20

Utility PV string inverter

The SG350HX-20 is a 1500 V DC, six-MPPT utility inverter with 800 V three-phase AC output. Sungrow rates apparent power differently at 30, 40 and 50 °C. Its communication path uses RS485_1 or power-line communication through a Sungrow logger; a third-party register contract is still needed.

Sungrow SG350HX-20 utility PV inverter
  • RS485

Utility PV string inverter

Compatibility

External monitoring requires an exact-model protocol

The exact-family manual assigns RS485_1 to monitoring, RS485_2 to tracker communication and PLC over AC conductors to a Sungrow logger. Logger-side transparent Modbus RTU does not supply an SG350HX-20 firmware-matched register map or a native inverter TCP endpoint. No Edge path is established.

SG350HX-20 with English manual Ver13, October 2024, and exact-model datasheet V7. Check the installed nameplate, firmware, logger and regional grid configuration. SG350HX without the -20 suffix and SG320HX-20 are separate selections.

Models

Download
ModelsInterfaceRoute into Edge
SG350HX-20Six MPPTs, up to five DC connectors per MPPT, 75 A maximum PV input per MPPTRS485_1 is the monitoring port; alternative PLC needs a compatible Sungrow data logger. Confirm the external protocol for the installed firmware.
SG320HX-20The shared manual lists 300 kVA at 51 °C for SG320HX-20; SG350HX-20 lists 295 kVA at 50 °C. Both list 352 kVA at 30 °C and 320 kVA at 40 °C.Keep model and ambient assumptions attached to measurements and sizing; do not choose a register map by enclosure likeness.
SG350HX, without -20An SG350HX document is not the exact SG350HX-20 datasheet used here.Match the full suffix and manufacturer document revision before selecting hardware or protocol.

Specifications

The SG350HX-20 V7 datasheet and Ver13 manual agree on six MPPTs, five connector positions each, 75 A maximum PV input per MPPT, 1500 V maximum DC input and an 800 V nominal three-phase AC connection. SG320HX-20 shares much of the enclosure but has a different high-temperature apparent-power row.12

Exact model
SG350HX-20, V7 datasheet; do not substitute SG350HX without -2023
PV voltage
1500 V maximum; 500–1500 V MPPT range; 550 V startup2
PV inputs
Six MPPTs, up to five input connectors each; 75 A maximum input per MPPT2
Temperature-rated AC output
352 kVA at 30 °C; 320 kVA at 40 °C; 295 kVA at 50 °C12
AC connection
800 V nominal, three-phase with protective earth; 640–920 V range2
Efficiency
99.02% maximum; 98.8% European efficiency2
Monitoring port
COM1 RS485_1 for inverter monitoring or PLC through a Sungrow logger1
Tracker port
COM1 RS485_2 on pins 7 and 8 for tracking-system communication1
Environment
IP66; -30 to +60 °C ambient range; altitude to 5000 m with derating above 4000 m2
Dimensions and weight
1148 × 779 × 371 mm; ≤106 kg, with manufacturer-stated ±8% component variation2

Interface

Documented measurements and integration boundaries for SG350HX-20.

  • The local iSolarCloud interface documents string and MPPT electrical quantities, AC power, voltages, current and grid frequency. These are app-visible quantities, not a published external register list.
  • The manual describes inverter yield, operating conditions and event histories; it does not establish an SG350HX-20 external scaling, update interval or accuracy class.
  • A utility plant needs separate meter and tracker identities. Inverter yield alone does not prove revenue-meter output, curtailment delivery or the grid-point import/export value.

Assessment

SG350HX-20 V7 datasheet and Ver13 family manual; external protocol and firmware applicability are unverified.

InteroperabilityLimited
COM1 RS485_1 monitoring, serial settings and PLC logger topology are documented. An exact SG350HX-20 external register map and firmware scope remain necessary for independent telemetry.1
AccuracyLimited
The local app reports electrical quantities and yield, but an external point model, accuracy and grid-meter identity are not established by the retained sources.1
SecuritySupported with conditions
The local app uses accounts and supports changing its initial password. External RS485 access requires installation safeguards; the manual does not establish encryption or authenticated external reads.1
ReliabilitySupported with conditions
The manual documents operating logs, up to 400 fault entries and 400 event entries, fault diagnostics and maintenance. Continued operation depends on the specified cooling and electrical installation; retention duration through power loss is not established.12
RuggednessSupported with conditions
IP66, published temperature and altitude limits, surge protection and a fan-maintenance procedure support utility installations within the stated derating, ventilation and site conditions.12
ScalabilitySupported with conditions
The serial interface offers addresses 1–246 and multiple baud rates. Daisy-chain capacity belongs to the selected logger, while polling load and client limits need separate protocol confirmation.1
LifecycleSupported with conditions
Sungrow publishes an exact SG350HX-20 datasheet and a manual that includes its own column. Preserve those document revisions alongside firmware and the logger contract.123

Setup

  1. Confirm the -20 variant

    Photograph the full model plate and record firmware, logger and installed configuration. Compare the SG350HX-20 datasheet and manual column rather than a nearby SG350HX or SG320HX document.

  2. Trace the monitoring route

    Identify whether the plant uses COM1 RS485_1 to a logger or PLC over the AC cables. Record the RS485_2 tracker connection separately and preserve the existing bus controller.

  3. Request the exact read contract

    Obtain the applicable SG350HX-20 protocol and logger forwarding description from Sungrow or the plant integrator. Check firmware, address convention, read function, scaling, timestamps and coexistence before designing Edge polling.

  4. Validate a bounded pilot

    Compare one or two approved read-only operational values with simultaneous local readings. Record units, signs, quality and loss-of-communication handling; use a separate meter for grid-point energy.

  5. Keep control ownership explicit

    Document who owns inverter commands, export limits and grid functions. Do not enable writes or VPP dispatch from this selection guide.

Common questions

Can RS485_2 serve a second monitoring controller?
The Ver13 manual assigns COM1 RS485_2 to tracker communication. Monitoring uses RS485_1, while the alternative PLC path depends on a Sungrow logger. Survey the commissioned topology before adding any client.1
Does PLC mean the inverter has a Modbus TCP endpoint?
No. PLC here is communication over AC conductors to the Sungrow logger. The manual describes transparent Modbus RTU through the logger’s RS485 interface but does not document a native SG350HX-20 TCP server or an external register map.1
Can this guide qualify VPP dispatch?
It describes selection and monitoring boundaries only. Active or reactive-power commands and grid settings need a separate manufacturer-approved control contract, plant-owner permission and witnessed site acceptance.1

Sources

  1. SG305HX / SG320HX-20 / SG350HX-20 / SG250HX-20 user manual, Ver13, October 2024 (opens in a new tab) (PDF) Sungrow
  2. SG350HX-20 global datasheet, V7 (opens in a new tab) (PDF) Sungrow
  3. SG350HX-20 product and document page (opens in a new tab) Sungrow

Further reading

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