≤75 ms Communication Refresh
Specified RS485 communication refresh time of ≤75 ms for applications requiring timely meter-side data updates.
DEM3A302 100 A Three-Phase DIN-Rail Energy Meter with RS485 and TOU
DEM3A302 is a 3P DIN-rail, direct-connected 3P3W (Delta) / 3P4W energy meter rated up to 100 A. It supports RS485 communication with Modbus RTU and DL/T 645-2007 compatibility, a specified communication refresh time of ≤75 ms, four TOU tariffs with RTC scheduling plus external tariff switching, and flexible energy calculation. The meter includes an internal battery for RTC timekeeping.
Direct connection
3P3W (Delta) / 3P4W
MID Certified
MID
120/208–230/400 V 3-phase rated voltage
100 A Maximum current (Imax)
54 mm DIN-rail width
−40°C to +70°C Operating temperature
Product Highlights
Fast Data Refresh for three-phase direct metering
Class 0.5 Active Energy Accuracy
Class 0.5 (Class C) active-energy measurement in accordance with IEC 62053-21 supports reliable energy monitoring and submetering applications.
RS485 with Dual Protocol
Supports RS485 communication with Modbus RTU and DL/T 645-2007 compatibility, with configurable baud rates from 9.6 to 115.2 kbps and addresses from 1 to 247.
TOU Tariffs and Multi-Tariff Support
Supports four internal TOU tariffs with RTC scheduling plus external tariff switching. Includes an internal battery for RTC timekeeping.
Flexible Energy Calculation
Supports forward, reverse, absolute-value, algebraic-sum and net-energy calculation modes for flexible submetering applications.
Internal Battery and RTC Timekeeping
Includes an internal battery for RTC timekeeping, enabling four TOU tariffs with time-scheduled switching.
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Explore ApplicationTechnical Specifications
Technical Specifications
| Connection type | Direct connection |
| Wire system | 3P3W (Delta) / 3P4W |
| Rated voltage (Un) | 3 × 120/208–230/400 V |
| Voltage tolerance | 0.8 to 1.15 Un |
| Frequency | 50/60 Hz |
| Current connection | Direct connection |
| Basic current (Ib) | 5 A |
| Minimum current (Imin) | 0.15 A (MID) / 0.25 A (IEC) |
| Maximum current (Imax) | 100 A |
| Power consumption | ≤2 W / 10 VA |
| Pulse constant | 1000 imp/kWh |
| Voltage accuracy | ±0.5 % |
| Current accuracy | ±0.5 % |
| Frequency accuracy | ±0.5 % |
| Active power accuracy | ±0.5 % |
| Reactive power accuracy | ±1 % |
| Active energy accuracy | Class 0.5 |
| Reactive energy accuracy | Class 1 |
| Communication interface | RS485 |
| Protocol | Modbus RTU and DL/T 645-2007 |
| Communication type | Bidirectional |
| Communication address | 1 to 247 |
| Baud rate | 9.6 / 19.2 / 38.4 / 57.6 / 115.2 kbps |
| Parity | None / Odd / Even |
| Specified communication refresh time | ≤75 ms |
| Display and controls | Backlit LCD, 500 ms refresh, page navigation and setting buttons |
| LED indicator | Red pulse LED |
| Metering functions | Energy, power, power factor and harmonic monitoring |
| Energy calculation | Forward, reverse, absolute-value, algebraic-sum and net-energy modes |
| Tariff function | Four TOU tariffs with RTC scheduling plus external tariff switching; internal battery for timekeeping |
| Diagnostics and alarms | EEP self-diagnostics and configurable monitoring alarms |
| Other functions | Local firmware upgrade, wiring check, screen saver, page filter and runtime-hour counter |
| Operating temperature | −40°C to +70°C |
| Ingress protection | IP20; install in an IP54 outdoor or IP51 indoor enclosure |
| Overvoltage category | OVC III |
| Protection class | Class II |
| Rated impulse withstand voltage | 6 kV |
| Applicable standards | IEC 62052-11:2020 / IEC 62053-21:2020 / IEC 62053-23:2020 / EN 50470-3:2022 |
Structure & Dimensions
DEM3A302 Dimensions & Wiring
Dimensions
Wiring
FAQ
Product FAQ
What is DEM3A302?
DEM3A302 is a 3P DIN-rail, direct-connected 3P3W (Delta) / 3P4W energy meter rated up to 100 A with RS485 communication, four TOU tariffs, internal battery and RTC timekeeping.
What communication protocols does DEM3A302 support?
RS485 with Modbus RTU and DL/T 645-2007, baud rates from 9.6 to 115.2 kbps, addresses 1–247. Confirm register list and settings before deployment.
What tariff functions does DEM3A302 provide?
Four internal TOU tariffs with RTC scheduling (8 time slots) plus external tariff switching. Internal battery maintains RTC timekeeping. For a battery-free variant, see DEM3A202.
What is the difference between DEM3A302, DEM3A202 and DEM3A001?
DEM3A302 has RS485 + internal battery + four TOU tariffs. DEM3A202 has RS485 + switched tariff only (no battery). DEM3A001 has SO pulse output only (no RS485, no tariff, no battery).
What is the MID certification status?
MID B+D certified by SGS UK. Verify the exact model scope on the certificate-verification page.
What is the operating temperature range?
−40°C to +70°C. Suitable for outdoor installations when installed in an appropriately rated enclosure.
Product Downloads
Product Datasheet Download
Datasheet
DEM3A Series Product Datasheet
Official DEM3A series datasheet covering product overview, specifications, wiring and dimensions.
Download PDF- Product overview and features
- Technical specifications
- Wiring diagrams and dimensions
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