≤75 ms Communication Refresh
The controlled specification states an M-Bus communication refresh time of ≤75 ms for applications that require timely meter-side data updates.
DEM1E204 45 A Single-Phase DIN-Rail Energy Meter with M-Bus
DEM1E204 is a single-phase, direct-connected DIN-rail energy meter for 1P2W systems with a maximum current of 45 A and wired M-Bus communication in accordance with EN 13757-3. It is rated 120–230 V with a basic current of 5 A, measures Class 0.5 (Class C) active energy, and operates over −40°C to +70°C. The meter occupies 1P (18 mm) on a standard 35 mm DIN rail and is MID B+D certified by SGS UK. This model has no internal battery, RTC or TOU schedule; it provides externally switched dual-tariff metering only.
DIN-Rail Mounting (1P, 18 mm)
1P2W Direct Connection
MID B+D Certified
MID
45 A Maximum current (Imax)
120–230 V Rated voltage
Class 0.5 (Class C) Active energy accuracy
−40°C to +70°C Operating temperature
Product Highlights
Compact M-Bus Metering with Fast Data Refresh
Class 0.5 Active Energy Accuracy
Class 0.5 (Class C) active-energy and Class 1 (Class B) reactive-energy measurement in accordance with IEC 62053-21 and IEC 62053-24.
M-Bus System Integration
Two-way M-Bus communication in accordance with EN 13757-3, with default address 1, broadcast address 254 and address range 1–250 at 2400 bps (8E1), so the meter connects directly to an existing M-Bus concentrator loop without protocol conversion.
Externally Switched Dual Tariff
A volt-free digital input switches between two tariffs (open = tariff 1, closed = tariff 2). No internal battery, RTC or TOU schedule.
Flexible Energy Calculation
Supports forward + reverse (absolute value), forward − reverse (algebraic sum), forward-only and reverse-only energy calculation modes for different submetering requirements.
Battery-Free Design
No internal battery, RTC or TOU schedule. Externally switched dual-tariff input only, which reduces component count and removes battery replacement from the maintenance scope of a sealed meter.
Applications
Applications and Selection Guidance
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Explore ApplicationTechnical Specifications
Technical Specifications
| Voltage connection | Direct connection |
| Rated voltage | 120–230 V |
| Voltage tolerance | 0.8 to 1.2 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) | 45 A |
| Pulse constant | 1000 imp/kWh |
| Power consumption | ≤2 W / 10 VA |
| Active energy accuracy | Class 0.5 (Class C) |
| Reactive energy accuracy | Class 1 (Class B) |
| Voltage accuracy | ±0.5% |
| Current accuracy | ±0.5% |
| Frequency accuracy | ±0.5% |
| Active power accuracy | ±0.5% |
| Reactive power accuracy | ±1% |
| Communication interface | M-Bus |
| Protocol | M-Bus (EN 13757-3) |
| Communication type | Bidirectional |
| Baud rate | 2400 bps (fixed) |
| Frame format | 8 data bits / 1 stop bit / even parity (8E1) |
| M-Bus address | Default 1, broadcast 254, range 1–250 |
| Refresh time | ≤75 ms |
| Display | LCD 6+2 |
| LCD refresh time | 500 ms |
| Pulse indicator | Red LED |
| Keys | Page / Set |
| IP rating | IP30 |
| OVC (overvoltage category) | Class III |
| Insulation class | Class II |
| Installation | 35 mm DIN rail, 1P (18 mm) |
| Wiring system | Direct connection, 1P2W |
| Dimensions (H × W × D) | 18 mm × 94 mm × 62.4 mm |
| Operating temperature | −40°C to +70°C |
| Relative humidity | ≤95%, non-condensing |
| Altitude | ≤2000 m |
| Rated impulse voltage | 6 kV |
| Standards | IEC 62052-11:2020 / IEC 62053-21:2020 / IEC 62053-24:2020 / EN 50470-3:2022 |
Structure & Dimensions
DEM1E204 Dimensions & Wiring
Dimensions
Wiring
FAQ
Product FAQ
What is DEM1E204?
DEM1E204 is a single-phase, direct-connected DIN-rail energy meter for 1P2W systems with a maximum current of 45 A and wired M-Bus communication in accordance with EN 13757-3. It is rated 120–230 V with a basic current of 5 A, measures Class 0.5 (Class C) active energy, and operates over −40°C to +70°C. The meter occupies 1P (18 mm) on a standard 35 mm DIN rail and is MID B+D certified by SGS UK. This model has no internal battery, RTC or TOU schedule; it provides externally switched dual-tariff metering only.
What communication protocol does it use?
M-Bus in accordance with EN 13757-3, bidirectional, 2400 bps fixed, 8 data bits / 1 stop bit / even parity, address default 1 with a range of 1–250 and broadcast address 254.
What is the maximum current?
The maximum current (Imax) is 45 A on a direct connection.
What is the active energy accuracy?
Class 0.5 (Class C) active energy and Class 1 (Class B) reactive energy.
What does the ≤75 ms specification refer to?
The controlled specification states a communication refresh time of ≤75 ms for the M-Bus communication function. End-to-end system performance also depends on concentrator polling and network configuration.
Does it include RTC and TOU tariffs?
No — this model has no internal battery, RTC or TOU schedule. It supports externally switched dual-tariff metering only. For the TOU variant see DEM1E304.
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