Three-Phase Four-Wire Electronic Prepaid Energy Meter
Three-phase four-wire prepaid metering with class B/C active energy accuracy, 5 tariffs across 14 time segments, prepaid trip control and bidirectional active energy measurement.
Overview
Key Features
Accurate bidirectional metering
Class B/C active energy accuracy with forward and reverse active energy measurement.
Multiple communication protocols
RS485 with DL/T645 and MODBUS-RTU, 4G optional.
Multi-tariff time-of-use billing
5 tariffs, 14 time segments and 8 daily tariff tables.
Prepaid trip control
Relay output drives prepaid trip, alarm and remote control.
Two form factors
Three-phase 4P and 7P versions, direct or transformer connection.
Long-term data retention
Outage data retained for at least 10 years; clock accuracy ≤0.5s.
Technical Data
| Rated voltage | 3×220/380V 50Hz three-phase four-wire |
| Accuracy class | Active energy class B (±1.0%/±1.5%) / class C (±0.5%/±1.0%) |
| Current specification | 0.2-0.5(30)A, 5(30)A and others (confirmed on order) |
| Communication protocol | DL/T645-2007, DL/T645-1997, MODBUS-RTU |
| Communication interface | RS485 (dual RS485 on some models), 4G optional |
| Baud rate | 1200 / 2400 / 4800 / 9600bps (2400 default) |
| Energy constant | 400imp/kWh |
| Billing functions | 5 tariffs / 14 time segments / 8 daily tariff tables, prepaid, forward and reverse active energy |
| Control output | Relay output for prepaid trip, alarm and remote control |
| Display | LCD with push buttons |
| Mounting | 35mm standard DIN rail, recommended height 1.8m |
| Protection requirement | Must be installed in an enclosure rated IP51 or higher |
| Applicable standard | GB/T 17215.321-2021 |
Models & Selection
| Parameter | DTSY1889 three-phase 4P DIN rail | DTSY1889 three-phase 7P DIN rail |
|---|---|---|
| Dimensions | 72×100×100mm | 126×100×75mm |
| Wiring | Direct connection / CT connection | Direct connection / CT connection |
| Rated voltage | 3×220/380V 50Hz | 3×220/380V 50Hz |
| Accuracy class | Active energy class B / class C | Active energy class B / class C |
| Energy constant | 400imp/kWh | 400imp/kWh |
Model naming rule：DTSY1889
Installation
FAQ
How is the prepaid function implemented?
Prepaid trip and reconnection are driven by a relay control output, which also handles alarm and remote control. The meter works with the electricity vending system that issues credit to the customer.
Which accuracy classes are available?
Active energy class B at ±1.0%/±1.5% and class C at ±0.5%/±1.0% are both available. The class is chosen to match the metering requirements of the installation.
Which communication protocols are supported?
DL/T645-2007, DL/T645-1997 and MODBUS-RTU are supported over RS485, with dual RS485 on some models and 4G optional. Baud rate is selectable from 1200 to 9600bps, 2400 by default.
What are the dimensions and mounting requirements?
The three-phase 4P version measures 72×100×100mm and the 7P version 126×100×75mm. Both mount on a 35mm DIN rail at a recommended height of 1.8m inside an IP51 enclosure.
What certification applies and how is pricing provided?
Certification is held through a CE / CMA / CNAS accredited laboratory. Price and lead time are quoted per specification; Request a quote with the model, current specification and accuracy class.