NewTrend · three-phase energy metering and relay control
Product overview
The DTS238-7 W is a three-phase four-wire energy meter with RS485 reading and relay control. This direct-connected 10(80)A version is marked 3 × 220/380V and 3 × 230/400V at 50/60Hz. A backlit LCD, front keys and status indicators provide local access to measurements and settings.
Technical selection summary
| Model | DTS238-7 W |
|---|---|
| System | Three-phase four-wire AC |
| Nameplate voltage ratings | 3 × 220/380V and 3 × 230/400V |
| Rated / maximum current | 10(80)A; direct connection with relay control |
| Frequency | 50/60Hz |
| Normal / limit voltage range | 90–110% Un / 70–120% Un |
| Accuracy | Active energy Class 1; reactive energy Class 2; RMS Class 0.5 |
| Measurements | Phase voltage/current, active/reactive power, power factor and frequency |
| Energy registers | Total, import/export active energy; reactive energy; resettable interval energy |
| Display | Backlit LCD with SET, up and down keys |
| Control | Remote relay on/off through RS485 |
| Communication | RS485; MODBUS-RTU |
| Baud rate | 1200–9600bps; default 9600bps |
| Serial format | 8 data bits, no parity, 1 stop bit; address 1–247 |
| Pulse constant | 400imp/kWh on the illustrated unit |
| Pulse output | Passive, optically isolated; 80 ±5ms |
| Indicators | Phase-loss, energy pulse and relay state |
| Data retention | More than 15 years without power |
| Protection | IP20 |
| Power consumption | <1W / 10VA |
| Operating temperature | −25°C to +70°C |
| Mounting | 35mm DIN rail; bottom main-terminal wiring |
| Dimensions | 93mm high × 126mm wide × 65mm deep |
| Standard markings | IEC62053-21; IEC62052-11 |
Energy and electrical-parameter monitoring
The meter provides total, imported and exported active energy, reactive energy and resettable interval energy. Reverse energy is included in total accumulation. The LCD also displays voltage, current, active power, reactive power, power factor and frequency, with front-key navigation between readings.
Front controls and relay indication
Hold SET for three seconds to enter the communication-address and baud-rate settings. The up and down keys step through display items and change values in setting mode. The phase indicators identify phase loss, and the pulse LED flashes according to the measured load. The relay indicator lights when the relay is disconnected and is off when the relay is switched on.
RS485 remote reading and switching
The MODBUS-RTU interface supports remote meter reading, relay on/off control and the supported energy-reset command. Baud rate is adjustable from 1200 to 9600bps, default 9600bps. The serial format uses eight data bits, no parity and one stop bit, with meter addresses from 1 to 247.
Three-phase direct connection
The wiring photograph shows the three phase input and output paths, together with neutral and the auxiliary communication connectors. Main power wiring is arranged at the bottom of this enclosure. Follow the phase sequence and terminal markings on the selected meter, and isolate the supply before installation or servicing.
Register map and data integration
The register map preserves the available energy and electrical-parameter addresses, read/write permissions, data types and scaling. Use the documented access permissions for meter data and configuration, and the supported relay-control commands when integrating the meter into an RS485 system.
Dimensions and DIN-rail installation
The enclosure measures 93mm high, 126mm wide and 65mm deep. The drawing also shows a 51mm depth reference, 35mm rail section and 45mm front section. Mount the meter on a standard 35mm DIN rail, with access to the terminal covers, front display and keys.
Data retention and applications
Energy data remains stored for more than 15 years after power loss. The meter is suitable for three-phase residential and commercial submetering, industrial distribution monitoring, bidirectional energy measurement and remotely controlled loads connected through an RS485 system.
