DL/T 645 + Modbus RTU
RS485 carries DL/T 645 and Modbus RTU at up to 115200 bps for EV charging and DC energy-management integration.
Product
DEM2D103 DC Energy Meter with Multi-Tariff & Relay
DIN-rail DC energy meter with external 75 mV shunt, battery backup, multi-tariff (T1–T4) and relay output, and 9–60 V DC auxiliary supply for EV charging.
DIN-Rail Mounting
External Shunt (75 mV)
Up to 2000 A 75 mV external shunt
9–60 V DC Auxiliary power supply
36 mm DIN-rail width (2P)
−25°C to +70°C Operating temperature
Product Highlights
DC Metering with Multi-Tariff and Relay Control
Class 1.0 Active Energy Accuracy
Class 1.0 active energy accuracy for reliable DC energy measurement and monitoring in EV charging applications.
External Shunt Flexibility
75 mV external shunt sampling supports primary-side currents up to 2000 A with configurable current settings, enabling flexible current-range configuration for different DC charging power levels.
Battery Backup, Multi-Tariff & Relay
Supports four tariffs (T1–T4), internal battery-assisted timekeeping and an auxiliary relay output on terminals 5/6.
6+2 LCD Display
6+2-digit LCD displays DC energy, voltage, current and power for clear on-site monitoring.
Overcurrent Alarm, Red Backlight
Backlight turns red on overcurrent for immediate visual fault indication in DC metering.
Applications
Applications and Selection Guidance
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Explore ApplicationTechnical Specifications
Technical Specifications
| Voltage connection | DC 5–1000 V |
| Current connection | External shunt (75 mV) |
| Maximum current | 2000 A (75 mV shunt; 200 A default) |
| Auxiliary power supply | 9–60 V DC |
| Impulse constant | 1000 imp/kWh |
| Power consumption | ≤8 VA / ≤0.4 W |
| Active energy accuracy | Class 1.0 |
| Current accuracy | 0.5% |
| Voltage accuracy | 0.5% |
| Active power accuracy | 1.0% |
| Communication interface | RS485 |
| Protocol | DL/T 645, Modbus RTU |
| Baud rate | up to 115200 bps (default) |
| Display | LCD 6+2 |
| Battery / tariff / relay | Battery backup, multi-tariff (T1–T4), auxiliary relay output (terminals 5/6) |
| Overcurrent alarm | Backlight turns red |
| AC withstand voltage | 4400 V/min |
| Impulse withstand voltage | 6.4 kV 1.2/50 μs |
| Installation | 35 mm DIN rail, 2-module |
| Operating temperature | −25°C to +70°C |
| Humidity | ≤95% |
Structure & Dimensions
DEM2D103 Dimensions & Wiring
Dimensions
Wiring
FAQ
Product FAQ
What is DEM2D103?
DEM2D103 is a DIN-rail DC energy meter using a 75 mV external shunt for measurement up to 2000 A. It supports RS485 communication, an internal battery, four-tariff metering and an auxiliary relay output, with a 9–60 V DC auxiliary power supply.
What current range does it support?
External shunt sampling at 75 mV, supporting a primary-side current up to 2000 A (200 A default).
What communication protocols does it support?
RS485 supports DL/T 645 and Modbus RTU dual protocols at up to 115200 bps.
What is the accuracy?
Class 1.0 active energy accuracy, with 0.5% current and voltage accuracy and 1.0% active power accuracy.
What auxiliary power supply does it use?
9–60 V DC
Does DEM2D103 support a battery, multi-tariff functions and relay output?
Yes. DEM2D103 includes an internal battery for time-related metering functions, supports four tariffs (T1–T4), and provides an auxiliary relay output on terminals 5 and 6. Relay contact ratings should be confirmed for the intended application.
Product Downloads
Product Datasheet Download
Datasheet
DEM2D Series Product Datasheet
Official DEM2D 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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