Hoymiles Three-phase Smart Meter

1 Safety Instruction

1.1 Safety Symbols

1.2 Personnel Requirements

This document is only applicable to qualified personnel who have received professional training and possess the following skills:

• Knowledge of and compliance with this document and all safety instructions.
• Familiarity with all safety specifications of the electrical system.
• Understanding of the composition and working principles of the grid-tied PV power system and local regulations.
• Proficiency in energy meter installation, operation, and maintenance.

Note:

• The qualified personnel must wear personal protective equipment (PPE) during all operations.
• The qualified personnel should comply with local laws and regulations during installation and operation. The safety instructions in this document are only supplements to laws and regulations.

1.3 Product-related Requirements

• When transporting and unpacking the products, please confirm they are not severely impacted.
• The package of the meter should use materials that can meet environmental requirements.
• The instrument and accessories shall be stored in dry and ventilated places, to avoid humidity and corrosive gas erosion. The storage environment temperature is -40°C to 70°C, and the relative humidity should be no more than 75%.
• Transport and store the product based on transportation, basic environmental conditions, and testing methods for instruments and meters of JB/T9329-1999.

1.4 Disclaimer

Hoymiles shall not be liable for the following situations:

• Any damage caused by incorrect installation and operation.
• Any damage caused by improper transportation and storage.
• Any damage caused by unauthorized modifications to the product.
• Any installation, operation, and maintenance performed by unqualified personnel.
• Failure to comply with all safety and operation instructions described in this document.

1.5 Maintenance and Replacement

• Disconnect the power supply before any maintenance and repair operation.
• All maintenance and replacement operations must be performed by qualified personnel.
• It is recommended to carry out regular inspection and maintenance for safety reasons.
• If users find any quality problem within 18 months from the date of dispatch, Hoymiles is responsible for repairing or replacing it for free, on the condition that users operate the product according to the manual's provision, and the seal is intact.

2 Product Introduction

2.1 Product Overview

Type DTSU666 three-phase smart meter (Din-rail), referred to as the "instrument", adopts a large-scale integrated circuit and digital sampling technology. It is designed for power monitoring and energy metering demands in electric power systems, communication industry, construction industry, etc. It is a new generation of intelligent instruments combining measurement and communication functions, mainly applied to measure and display electric parameters like three voltages, three currents, active power, reactive power, frequency, positive and negative energy, and four-quadrant energy. It uses standard DIN35 mm din rail mounting and a modular design, characterized by small volume, easy installation, and networking. It is widely applied to internal energy monitoring and assessment for industrial and mining enterprises, hotels, schools, and large public buildings.

This type of energy meter conforms to the following standards:

• IEC 61010-1:2010 “Safety requirements for electrical requirement for measurement, control, and laboratory use Part1: General requirements”;
• IEC 61326-1:2013 “Electrical requirement for measurement, control, and laboratory use-EMC requirements Part1: General requirements”;
• MODBUS-RTU protocol.

2.2 Product Naming Rule

The product naming rule follows the format: D/T/S SU 666.

• D/T/S: Indicates the connection mode. D for Single-phase AC Energy Meter, T for Three-phase four-wire AC Energy Meter, S for Three-phase three-wire AC Energy Meter.
• SU: Indicates the electronic type (Energy Meter).
• 666: Design Number.
• DIN Rail: Indicates the mounting type.

Table 2-1 Model Specification

2.3 Working Principle

2.3.1 Working Principle Diagram

The instrument is composed of a highly accurate metering integrated circuit (ASIC), management MCU, memory chip, RS485 communication module, etc. The working principle block diagram is shown below:

Diagram Description: The diagram shows inputs for Current (Ia, Ib, Ic) and Voltage (Ua, Ub, Uc) being sampled. These samples go to a Metering ASIC. The ASIC is connected to an LCD Display, Memory, Key Stroke input, RS485 Interface, Real-time Clock, and Impulse Output. The ASIC receives power from a Power Supply unit managed by Power Management.

2.3.2 Metering Part Principle

The special metering integrated circuit (ASIC) uses a type of A/D conversion to measure voltage and current. It processes digital signals to measure active power, reactive power, apparent power, active energy, reactive energy, and apparent energy for each phase and combined phase. It also measures current and voltage effective values, power factor, phase angle, and frequency. The chip provides an SPI interface for parameter metering and calibration with the management MCU.

2.3.3 Data Processing Part Principle

The Management MCU reads electrical parameters from the metering chips. It determines the current quadrant based on the data and the operating rate based on time. Energy values are added to the corresponding quadrant and total energy. It also calculates combined energy based on the energy combination mode and stores it.

2.4 Main Function

2.4.1 Display function

The displayed interface shows primary side electrical parameters and energy data (multiplied by current and voltage ratios). The energy value is displayed in seven bits, ranging from 0.00 kWh to 999999.9 kWh.

Diagram Description: A representation of the Liquid Crystal Display showing various symbols and numerical readouts.

Table 2-2 Display Interface

Note: Combined active energy = Positive active energy + Reserve active energy. The communication address of Modbus protocol is 1-247, and the factory default baud rate is 9600 bps, N.8.1. E1 means even check 1 stop bit, O1 means odd check 1 stop bit, and N1 means one stop bit without check. The display symbols may increase or decrease depending on the instrument's functions.

2.4.2 Programming Function

2.4.2.1 Programming Parameter

Table 2-3 Programming Parameter

2.4.2.2 Programming Operation

Button description: The "SET" button represents "confirmation" or "cursor shift" (when input digits); the "ESC" button represents "exit"; the "→" button represents "add". The input code is (default 701).

When input digits, "←" can be used as a cursor shift button; "→" is "add" button, "ESC" means exiting the programming operation interface or switching to the character interface from the digit modification interface; adding from the beginning after setting the digit to the maximum value.

Diagram Description: Figure 2-4 shows setting examples for communication address and baud rate, illustrating button presses (SET, ESC, →) and display changes.

Note: The communication address can also be set through the S-Miles App. Open the S-Miles App, tap "Toolkit → Meter Location", and enter the serial number of the smart meter; the communication address will be automatically set to 002. If two meters are required for an AC-coupled system, the address of the grid side meter should be set to 002, and the address of the PV side meter should be set to 001.

2.4.3 Communication Function

It has an RS485 communication interface, and the baud rate can be changed between 1200 bps, 2400 bps, 4800 bps, and 9600 bps. The factory default communication parameter is Modbus-RTU protocol; the baud rate is 9600 bps, with the calibration bit and stop bit to be n.1, and the instrument address is 1.

2.4.4 Energy Measurement Function

The horizontal axis of the measurement plane represents the current vector I (fixed on the horizontal axis), and the instantaneous voltage vector is used to represent the current power transmission. Compared with the current vector I, it has phase angle Φ. The counter-clockwise direction angle is positive.

Diagram Description: Figure 2-5 shows a measurement schematic diagram for energy four quadrants, illustrating the relationship between current, voltage, and power (P, Q, S) in different quadrants.

Note: The measurement method for the combined active energy depends on the contents of character words of the active combined mode.

Table 2-4 Character words of the active combined mode

Example: when the content of the active combination mode is 05, combined active energy = positive active energy + reverse active energy. Factory default value: combined active energy = positive energy.

The combined reactive energy of four quadrants can be measured, and the reactive energy can be set as the sum of arbitrarily four-quadrant energy, with its measurement mode depending on the contents of character words 1 and 2 of the reactive combination mode.

Table 2-5 Character words of the combined reactive combination mode

Explanation of bits:
0 bit: I quadrant reactive; 0-Not counted into combined reactive; 1-Counted into combined reactive.
First bit: I quadrant reactive; 0-Not counted into combined reactive; 1-Minus the quadrant reactive.
Second bit: II quadrant reactive; 0-Not counted into combined reactive; 1-Counted into combined reactive.
Third bit: II quadrant reactive; 0-Not counted into combined reactive; 1-Minus the quadrant reactive.
Fourth bit: III quadrant reactive; 0-Not counted into combined reactive; 1-Counted into combined reactive.
Fifth bit: III quadrant reactive; 0-Not counted into combined reactive; 1-Minus the quadrant reactive.
Sixth bit: IV quadrant reactive; 0-Not counted into combined reactive; 1-Counted into combined reactive.
Seventh bit: IV quadrant reactive; 0-Not counted into combined reactive; 1-Minus the quadrant reactive.

For example: when the content of the reactive combination mode is A5; Combined reactive energy = I quadrant reactive + II quadrant reactive - III quadrant reactive - IV quadrant reactive. Factory default value: combined reactive 1 energy=I + IV, combined reactive 2 energy=II + III.

2.5 Product Dimensions

Table 2-6 Product Structure

Diagram Description: Figure 2-6 shows the product dimensions with measurements for width, height, and depth, indicating the DIN35 rail mounting. Figure 2-7 shows the current cable terminal dimensions (conductor cross-sectional area ≤16 mm²). Figure 2-8 shows the RS485 cable terminal dimensions (conductor cross-sectional area: 0.25 mm²-1 mm²).

Note: The undeclared tolerance is ±1 mm. The information provided indicates the product size; the shape of different specifications may vary slightly.

2.6 Product Installation

[DANGER] Before connecting the cables, ensure that the smart meter is not damaged in any way. Otherwise, electric shocks or fires may occur.

[NOTICE] Before installation, please check whether the model and specifications of the products on the box are in line with the material; if not, please contact the supplier.

[NOTICE] Check whether the packing case of the product is damaged; if damaged, please contact the supplier.

[NOTICE] When unpacking the carton, if the shell has obvious signs caused by severe impact or falling, please contact the supplier as soon as possible.

[NOTICE] After the instrument is removed from the packing box, it should be placed in a flat and safe place, facing up, not overlaying for more than five layers. If the inner package or shell has been damaged, please do not install the product.

Diagram Description: Figure 2-9 illustrates the meter installation process.

Procedure (DC-coupled System)

• Clamp the meter to the guide rail directly, and install the meter and the rail in or near the distribution box, right after the utility meter.
• Connect grid L1/L2/L3/N to meter's terminals 3/6/9/10.
• Clamp three CTs to L1/L2/L3 and respectively connect wirings to terminals 13/14, 16/17, and 19/21. The arrow on the surface of CT should point to the grid.
• Connect the communication cable between the inverter and the smart meter.

Procedure (AC-coupled System)

• The smart meter 1 is connected to the grid port, and the smart meter 2 is connected to the GEN port. The connection method is the same as that described above.

Note: When installing, clip the end of the card slot into the guide rail. When disassembling, use a screwdriver to press the card to remove the instrument.

2.7 Typical Wiring

[DANGER] High voltage may cause an electric shock, which will result in serious injury, death, or serious property damage. Please strictly comply with the safety instructions in this document and other relevant documents.

Diagram Description: Figure 2-10 shows the Type of Wiring 3P4W. Figure 2-11 shows RS485 wiring.

Terminal Connections:

• Voltage signal: 3 - UA (Phase A voltage input terminal), 6 - UB (Phase B voltage input terminal), 9 - UC (Phase C voltage input terminal), 10 - UN (Phase N voltage input terminal)
• Current signal: 13 - IA* (Phase A current input terminal), 14 - IA (Phase A current output terminal), 16 - IB* (Phase B current input terminal), 17 - IB (Phase B current output terminal), 19 - IC* (Phase C current input terminal), 21 - IC (Phase C current output terminal)
• RS485 communication: 24 - A (RS485 terminal A), 25 - B (RS485 Terminal B)

3 Troubleshooting

4 Technical Specification

4.1 Limit of error caused by the current augment

Table 4-1 The limit value of the active percentage error of meters on balanced load

Note: In: secondary rated current of the current transformer; Ib: calibrated current of the meter. L: inductive; C: capacitive.

Table 4-2 The limit value of the reactive percentage error of meters on balanced load

Table 4-3 The limit value of the reactive percentage error of meters on balanced load

Table 4-4 The limit value of the reactive percentage error of meters on imbalanced load

4.2 Start

Under the power factor of 1.0 and started current, the instrument can be started and continuously measured. For multi-phase instruments, it will bring a balanced load. If the instrument is designed for dual directional energy measurement, it is applicable for each direction of energy.

Table 4-5 Start Current

4.3 Defluction

When the voltage is applied with no current flowing in the current circuit, the test output of the meter shall not produce more than one pulse. When testing, the current circuit shall be disconnected, and the applied voltage of the voltage circuit shall be 115% of the referenced voltage.

4.4 Environmental Parameter

• Limited working temperature range: -25°C - 70°C
• Relative humidity (annual average): ≤75%
• Altitude: ≤4000 m
• Atmospheric pressure: 63 kPa-106 kPa

4.5 Electrical Parameter

• Specified operating voltage range: 0.9 Un-1.1 Un
• Extended operating voltage range: 0.8 Un-1.15 Un
• Limiting operating voltage range: 0 Un-1.15 Un
• Voltage line power consumption: ≤1.5 W/6 VA
• Current line power consumption: I<10 A ≤0.2 VA; I≥10 A ≤0.4 VA
• Data storage time after power interruption: ≥10 years

4.6 Technical Parameter

(1) Secondary rated current of the current transformer.