Device overview
The Carlo Gavazzi EM511DINAV81XS1PFB is a compact single-phase energy analyzer for direct-connected circuits up to 45 A. This exact PFB model combines RS-485 Modbus RTU with bidirectional MID-certified active-energy registers, making it useful where both imported and exported energy must be measured and the readings may support cost allocation or certified sub-metering.
Core measurement features
The meter measures active, reactive and apparent energy together with voltage, current, active/reactive/apparent power, power factor, frequency, demand values and current/voltage harmonic distortion. The official datasheet specifies Class 1 active-energy accuracy to EN IEC 62053-21, MID Class B to EN 50470-3 and Class 2 reactive-energy accuracy. Current is wired directly through the meter at 5(45) A, so this model does not use external current transformers.
The PFB suffix matters when comparing EM511 variants. PFB models increment separate positive and negative energy counters according to power direction, and both imported kWh+ and exported kWh- counters are MID certified. PFA and SFA variants use an easy-connection behavior that does not provide the same bidirectional register result.
Installation
EM511 is a two-module DIN-rail device intended for a low-voltage switchboard. It is a single-phase, two-wire meter for 120-240 V L-N systems. Installation requires direct mains wiring and should be carried out by a qualified professional using the applicable local protective device, enclosure and conductor requirements. The 45 A limit is the meter's direct-connected circuit rating, not a CT ratio or a whole-building limit that can be expanded in software.
Communication and local access
This SKU includes a two-wire RS-485 Modbus RTU port. Carlo Gavazzi publishes the register map and supports addresses 1-247 with configurable baud rate and parity. Measurements and configuration remain available locally through the display, keypad, Modbus interface and UCS software; no vendor cloud is required for normal operation.
Home Assistant compatibility
Home Assistant can read the meter through its standard Modbus integration, but this is a protocol-level path rather than a native Carlo Gavazzi integration. A USB-to-RS-485 adapter or compatible Modbus gateway is required, and the installer must map the relevant EM511 registers with the correct address, data type and scaling. This makes the device attractive for local-data projects, while requiring more configuration work than a plug-and-play consumer monitor.
Solar and import/export monitoring
Because the PFB model exposes separate imported and exported active-energy counters, it can support solar import/export monitoring when installed at the appropriate connection point and wired with the correct direction. It measures energy flow; it does not itself control an inverter, battery or grid-export limit.
Best-fit scenarios
EM511 is best suited to certified single-phase sub-metering, commercial or residential cost allocation, individual machine or circuit monitoring, EV charging equipment and local Modbus-based energy-management systems. Buyers should confirm that a 45 A direct-connected meter fits the circuit, that the PFB bidirectional MID variant is supplied, and that local certification requirements accept this exact SKU.
Strengths and limitations
Key strengths are the exact 45 A direct measurement boundary, bidirectional MID registers, broad electrical-variable coverage, fast local Modbus communications and cloud-free operation. The main limitations are single-phase scope, professional mains installation, the need for manual register configuration in Home Assistant, and the absence of a public global price or stock promise.
Purchase and official sources
Carlo Gavazzi provides localized product and sales-network routes across Europe, the Americas and Asia-Pacific. The official product page is the safest starting point, but pricing, approvals and availability should be confirmed with the regional Carlo Gavazzi office or distributor.
Sources: official EM511 product page; EM511 datasheet dated 22 August 2024; EM511 user manual dated 9 April 2025; current EM511 Modbus communication protocol; Home Assistant Modbus documentation.