Deye 1Ph LV - single-phase hybrid inverter

Introduction

This document describes the integration between the Deye single-phase, low-voltage (48 V) hybrid inverter (the SUN-SGLP1 family, also sold under the Sunsynk brand) and the myPower24 online monitoring platform using the LoggerV data logger, for real-time monitoring, data logging, and plant control.

Phase A - Selection & Compatibility

1. Models covered

• SUN-SGLP1: Deye / Sunsynk (dual-branded, one protocol); product type: Hybrid Inverters. Shown under My Devices as Deye 1Ph LV.

2. Communication & compatibility

The inverter is a Modbus device; the LoggerV adopts it with an active Modbus probe (it reads the identity registers and checks the single-phase LV family code).

• RS-485 (Modbus RTU): serial; scan Modbus; LoggerV compatible: yes. The usual field connection.
• RS-232 (Modbus RTU): serial; scan Modbus; LoggerV compatible: yes.
• Ethernet (Modbus TCP): Modbus TCP is expressed as the Ethernet transport with a Modbus scan; LoggerV compatible: yes.
• Modbus address: factory default 1, set on the inverter's LCD under Modbus SN. The inverter's serial baud must match the LoggerV port's Bus Speed; myPower can also scan an address range if needed.
• Firmware: device: Not Specified (the Deye/Sunsynk manual states no minimum; the inverter's LCD shows the COMM and MCU firmware versions for reference); LoggerV: Not Specified.

3. Plant-control capability

In plant control the inverter is a Power Conversion System with PV and an off-grid switch (an HPCSO-class role). It is an active participant, not monitor-only. The LoggerV can:

• Limit / curtail PV for zero-export and grid-support: it writes the inverter's PV Power Limit register (register 53) and reads it back to confirm.
• Dispatch active power on a time-of-use schedule: when plant-control time-of-use is enabled, it drives the inverter's TOU setpoints and flags "Time of Use controlled by plant control" on the device.
• Register the battery as storage (optional): when Register Storage is on, the inverter's battery is exposed to plant control as a one-battery storage cluster (see section 8).

Start/stop (the On/Off control, register 43) is an operator action, not driven automatically. Reactive-power control is not implemented for this model.

4. Recorded data points

Logged to the platform (all recorded as a periodic average; the sampling period is device-wide):

• Storage Current, A, average.
• Storage Voltage, V, average.
• Grid Frequency, Hz, average.
• Load Frequency, Hz, average.
• DC Trans. Temperature, °C, average.
• Heatsink Temperature, °C, average.

5. Reference documents

None hosted yet.

Phase B - Installation & Commissioning

6. Wiring & connection

Connection diagrams are generated by the platform's Add-Device wizard; see How to add a device in myPower24. Wire the inverter to the LoggerV over RS-485 (A to A, B to B), RS-232, or Ethernet for Modbus TCP.

Device-specific notes (from the SUN-SGLP1 manual):

• Comms port: connect the LoggerV to the inverter over RS-485 (terminals A, B, GND) or RS-232. The inverter also has separate BMS (battery), Meter_CON (energy meter) and parallel ports; don't confuse them with the monitoring link. The exact connector and full pinout are in the inverter manual (see Reference documents).
• Modbus address: factory default 1, set on the LCD under Modbus SN (give each inverter on a shared bus a unique number).
• Battery protocol: on the LCD Batt Set 3 page, Lithium Mode is the BMS protocol code, chosen from the inverter's Approved Battery list for your battery model (see section 8).

7. Configuration steps

1. Connect the comms cable per the generated diagram.
2. Add the device on the LoggerV; see How to add a device in myPower24. Choose the SUN-SGLP1 (Deye / Sunsynk) device type, set the port's Bus Speed to match the inverter, and scan for the inverter's Modbus address (or a range if you are unsure of it).
3. On the inverter, set a unique Modbus address and a baud rate that matches the LoggerV port.

Phase C - Battery communication

8. Battery compatibility & configuration

The battery communicates with the inverter over a CAN BMS link so the inverter charges and discharges it directly from the battery's BMS. Set both ends to the same protocol.

On the inverter (on the device's Settings > Battery page):

• Control Mode: Lithium Battery for a battery with a BMS (register 200; 0 = Lead, 1 = Lithium). In lithium mode the inverter follows the battery's BMS; in lead-acid mode it follows voltage curves.
• Lithium Battery Type: in lithium mode this selects the battery's BMS protocol (a numeric code, register 325). For a Solar MD battery, set it to 0 (the Solar MD profile). On the inverter's own LCD this is the Lithium Mode code on the Batt Set 3 page (the manual notes the code is taken from the inverter's Approved Battery list for your battery model).
• Battery Capacity and Max Charge / Max Discharge Current: set to the battery's ratings.

On a Solar MD battery: set the battery to speak the Deye/Sunsynk BMS protocol. On the battery's own device page go to Settings > Installer > Control and, under Controlled Device Settings, set Controlled Device to Sunsynk (Deye and Sunsynk share one protocol; there is no separate "Deye" entry). The battery side is covered in full in Connect a Solar MD Li-ion Storage EX battery.

Register Storage (plant control). On the device's Settings > Storage Cluster page, Register Storage exposes the battery reached through this inverter to plant control as a storage cluster. Use it only for a battery the LoggerV can reach solely through the inverter. It takes effect on the next device reload, not immediately.

Phase D - Maintenance & Monitoring

9. Monitoring

Once connected, the device page has an Info tab (identity, hardware/firmware versions), a Data tab (default), and a Settings tab. The Data tab shows Battery (SOC, Power, Voltage, Current), Load, Grid and Temperature cards, plus a run-state dashboard (Standby / Self Test / Normal / Alert / Fault).

To confirm a healthy link: run state reads Normal and the live Battery SOC and Power update on the Data tab.

10. Troubleshooting

• The inverter doesn't appear after scanning. Almost always an RS-485 wiring, address, or baud problem: check A/B aren't swapped, the baud matches the port, and you scanned the address you set (or use a range scan). A response from the wrong Deye family is rejected as a scan failure rather than adopted.
• The device shows offline / no live data (after working). The inverter stopped communicating: check it is powered and the serial link is intact.
• "External CT clamp appears disconnected" warning. Raised when the external CT / smart-meter total reads 0 while the inverter is on-grid, usually an unplugged or mis-wired CT clamp. Check the CT connection and orientation; it clears once current is read again.
• No battery / BMS data. Both ends must agree on the protocol: inverter Control Mode = Lithium (and a matching Lithium Battery Type), battery Controlled Device = Sunsynk; then check the CAN BMS cable. A lost BMS link raises the inverter fault Bat_Comms_Lost (F58).
• Register Storage did nothing. It applies only on device reload; reload the device. Don't use it for a battery already connected directly to the LoggerV.

11. Who can do what

• Regular user (basic): open the inverter page and read live data once it is connected.
• Advanced user (advanced): add / scan the device and edit the Settings tab, including all battery configuration.
• OEM (oem): full device and firmware control.

The highest tier bypasses the lower-tier gates.

Tips and gotchas

• Address and baud are set on the inverter, not in myPower24, and the baud must match the LoggerV port.
• Deye and Sunsynk are one protocol: the battery's Controlled Device option is Sunsynk; there is no separate Deye option.
• Confirm on the Data tab: a healthy inverter shows run state Normal with live Battery SOC and Power.