Hoymiles Three-Phase Smart Meter Installation Guide

Overview

The Hoymiles Three-Phase Smart Meter enables real-time monitoring of household electricity consumption, grid import/export, and energy flow. When connected to a compatible Hoymiles energy storage system, it helps optimize self-consumption, manage battery charging and discharging, and support zero-export control.

Important: Installation must only be performed by a qualified electrician and must comply with all applicable local electrical regulations.

What's in the Box

  • Hoymiles Three-Phase Smart Meter
  • Three Current Transformers (CT Clamps)
  • RS485 Communication Cable
  • User Manual

Before Installation

Before starting installation, please ensure:

  • The main power supply is switched OFF.
  • The installation area is dry, clean, and safe.
  • You have access to the main distribution board.
  • The CT clamps and communication cables are undamaged.
  • The smart meter is compatible with your inverter or energy storage system.
⚠️ Risk of electric shock. Always disconnect power before working inside the electrical panel.

Installation

Step 1. Install the Smart Meter

  • Open the electrical distribution panel.
  • Mount the smart meter securely on a standard DIN rail.
  • Ensure sufficient space for wiring and future maintenance.

Step 2. Connect Voltage Wires

Connect the voltage terminals according to your three-phase grid configuration:

  • L1 → Phase 1
  • L2 → Phase 2
  • L3 → Phase 3
  • N → Neutral

Verify all wiring connections are secure before proceeding.

Step 3. Install Current Measurement

The Hoymiles Three-Phase Smart Meter is available in two versions: With CT and Without CT (Direct Measurement). Follow the installation instructions according to your model.

Option A: With CT Version

  • Locate the incoming grid cables for each phase.
  • Install one CT clamp on each phase conductor:
    • CT1 → L1
    • CT2 → L2
    • CT3 → L3
  • Ensure the arrow on each CT clamp points toward the load (household consumption side).
  • Fully close each CT clamp until it clicks into place.

Important: Incorrect CT orientation or phase assignment may result in inaccurate measurements.

Option B: Without CT (Direct Measurement)

  • No external CT clamps are required.
  • Connect L1, L2, L3 and Neutral directly through the smart meter according to the wiring diagram.
  • Ensure all terminal connections are properly tightened.
  • Verify that the connected current does not exceed the rated capacity of the meter.

Important: Direct measurement models are suitable for installations where the current remains within the meter's specified range.

Step 4. Connect CT Cables (CT Version Only)

For smart meters equipped with external CT clamps, connect the CT cables to the corresponding terminals:

  • CT1 → Phase L1
  • CT2 → Phase L2
  • CT3 → Phase L3

Confirm that all CT connections are firmly inserted and securely connected.

If you are using the Without CT (Direct Measurement) version, skip this step.

Step 5. Connect Communication Cable

Connect the RS485 communication cable between the Hoymiles Three-Phase Smart Meter and the compatible inverter, battery system, or energy management device.

Verify the communication wiring polarity:

  • A (+)
  • B (-)

Incorrect RS485 polarity may prevent communication between devices.

Step 6. Power On the System

  1. Close the electrical distribution panel.
  2. Restore power to the system.
  3. Wait for the smart meter to complete startup.

The smart meter should display:

  • Grid voltage
  • Current
  • Power consumption
  • Import/export energy data

Step 7. Verify Communication

Open the Hoymiles monitoring platform or S-Miles Home App.

Confirm that:

  • The smart meter is detected successfully.
  • Real-time household consumption data is displayed.
  • Grid import and export values update correctly.
  • Energy management functions operate normally.

Smart Meter Functions

When installed correctly, the Hoymiles Three-Phase Smart Meter provides:

  • ✓ Real-time household energy consumption monitoring
  • ✓ Grid import and export measurement
  • ✓ Self-consumption optimization
  • ✓ Zero-export control
  • ✓ Intelligent battery charging and discharging management
  • ✓ Energy flow visualization

CT Version vs Without CT Version

Feature With CT Without CT
Current measurement External CT clamps Direct measurement through the meter
External CT required Yes No
Main cable modification No interruption to existing cables Main conductors must pass through the meter
Recommended use Existing residential systems and retrofit installations New installations or electrical panels with sufficient space
Installation complexity Easier installation Requires direct electrical wiring

Troubleshooting

Issue Possible Solution
No data displayed
  • Check voltage wiring connections.
  • Confirm the smart meter has power.
  • Verify the meter is compatible with your system.
Communication failure
  • Check RS485 cable connections.
  • Verify A/B polarity.
  • Check communication settings in the monitoring platform.
Incorrect power direction
  • Check CT clamp orientation.
  • Ensure CT arrows point toward the household load.
  • Verify correct phase assignment.
Inaccurate readings
  • Confirm CT clamps are installed on the correct phases.
  • Ensure CT clamps are fully closed.
  • Check wiring connections.

Safety Information

  • Installation must be performed by a qualified electrician.
  • Never work on live electrical conductors.
  • Always disconnect the main power supply before installation.
  • Use appropriate personal protective equipment (PPE).
  • Follow all local electrical and grid regulations.
  • Do not modify or disassemble the smart meter or CT clamps.

Installation Complete

Once installation is complete, the Hoymiles Three-Phase Smart Meter will provide accurate real-time energy monitoring and enable advanced energy management features for your Hoymiles solar and storage system.