1. Overview

The DTS1791 and DSS1791 three-phase static energy meters are new instruments designed and manufactured based on the actual electricity consumption of industrial users, using imported specialized large-scale integrated circuits, 16 bit A/D conversion, digital multipliers, digital sampling processing technology, and SMT processes. This meter uses an independent three unit metering module to accurately measure the active energy of three-phase forward and reverse directions. Measurement errors have excellent long-term stability. Its performance meets the technical requirements of GB/T17215-2002 standard for three-phase energy meters.

Main features: It has good resistance to electromagnetic interference, low self consumption, high precision, anti electricity theft, wide range, long life, and can display liquid level.

This meter is suitable for ambient temperatures ranging from -10~50 ℃ and relative humidity not exceeding 85%.

2. Functions and Features

1. It has the function of bidirectional measurement of active energy, and the LCD display shows the total amount of electricity;

2. Equipped with RS-485 and infrared communication, it can remotely and conveniently read the total power of the electric energy meter;

3. Can set or retrieve parameters such as total power consumption, instrument constant, meter address, meter password, etc;

4. Equipped with a programming switch, capable of online programming;

5. The chip has a watchdog system inside, which makes data more secure and reliable, and power outage data can be stored for a long time (continuous power outages can be stored for more than 10 years);

6. The isolated power supplies provide reliable working power for the CPU, metering section, and RS485 interface.

7. It has a phase failure indication function.

8. Communication protocol

According to the "Multi function watt hour meter communication protocol" DL/T 645-1997 Chinese power industry standard.

3. Working principle

The working principle of DTS1791 and DSS1791 three-phase static energy meters is shown in Figure 1.

This electric energy meter adopts a three-phase power supply mode and can work normally under any single-phase power supply situation.

When the electric energy meter is working, the voltage and current are sampled separately by the sampling circuit and sent to the large-scale dedicated integrated circuit for buffering and amplification. Then, they are converted into digital signals by a 16 bit A/D converter, processed by a digital multiplier, and sent to the CPU for processing. Finally, the CPU sends the processed data to the display section, step counter, and other output units as needed.

Figure 1: Working principle diagram of DTS1791 and DSS1791 three-phase static energy meters

4. Specifications, models, and technical indicators

4.1 Specification and Model

4.2 Basic Error (Balance Load Error Limit)

Note: (Ib rated current Imax maximum current)

4.3 Start up

Under the conditions of reference voltage, reference frequency, and COS φ=1.0, the instrument should be able to continuously measure electricity with a load current of 0.001Ib (0.5 level) and 0.002Ib (1 level).

4.4 Submersion

When the rated voltage of the voltage circuit is 115% and there is no current in the current circuit, the test output of the instrument should not generate more than one pulse.

4.5 Voltage Range

Normal operating voltage: 0.9Un-1.1Un

Maximum operating voltage: 0.8Un-1.15Un

4.6 Power consumption

Voltage line power consumption: ≤ 2W and 5VA

Current line power consumption: ≤ 1VA

4.7 Climatic Conditions

Normal operating temperature: -10 ℃+45 ℃ Extreme operating temperature: -20℃ +55℃

Storage and transportation temperature: -25 ℃+70 ℃. The humidity can reach 95% for 30 days of the year (naturally diffused), and sometimes up to 85% for the rest of the time.

4.8 Mechanical dimensions

Dimensions: 228mm × 144mm × 72mm

4.9 Weight:About 1.2kg