Shelly Pro EM-50

Single-phase energy meter

A DIN-rail meter with two 50 A measurement channels, Ethernet and a separate contactor-control relay.

Shelly Pro EM-50
  • HTTP RPC
  • MQTT
  • Modbus TCP

Single-phase energy meter

Compatibility

Compatible with conditions

The local JSON API and MQTT allow a custom integration through Edge’s Node-RED integration workspace. This guide supplies read-only requests and validation checks, not a built-in driver or downloadable device template. Physical integration has not been tested.

SPEM-002CEBEU50 only. Use em1:0/em1:1 and em1data:0/em1data:1, not the three-phase EM component.

Route into Edge

Read an already commissioned meter on the same protected network

  • Wired
  • Edge
  • Platforms
Single-phase energy meter
Interface
Gateway
Edge
Output
Pro EM-50Shelly Pro EM-50
Protected EthernetSegmented LAN
ZGW-20 GatewayHosts Edge locally
EpiSensor EdgeEdge integration workspace
Customer platformMQTT · API · files
Ethernet
Protected Ethernet
Runs locally
Optional onward data
Use the configured local IP and authenticated RPC interface. Read EM1.GetStatus and EM1Data.GetStatus; keep numeric units and channel IDs with every value. The customer-platform output is optional; Edge remains the local system of record.

An MQTT broker and device publication settings are already configured

  • Wired
  • Edge
  • Platforms
Single-phase energy meter
Interface
Gateway
Edge
Output
Pro EM-50Shelly Pro EM-50
Protected EthernetSegmented LAN
ZGW-20 GatewayHosts Edge locally
EpiSensor EdgeEdge integration workspace
Customer platformMQTT · API · files
Ethernet
Protected Ethernet
Runs locally
Optional onward data
Consume the configured device topic prefix and component status JSON. Broker settings, authentication and notification options are installation-specific; do not assume a public broker or a fixed topic prefix. The customer-platform output is optional; Edge remains the local system of record.

The installed firmware exposes and enables the documented Modbus component

  • Modbus
  • Edge
  • Platforms
Single-phase energy meter
Interface
Gateway
Edge
Output
Pro EM-50Shelly Pro EM-50
Protected EthernetSegmented LAN
ZGW-20 GatewayHosts Edge locally
EpiSensor EdgeEdge Modbus client
Customer platformMQTT · API · files
Modbus TCP
Protected Ethernet
Runs locally
Optional onward data
Shelly documents TCP port 502 and per-component register blocks. Check Modbus.GetStatus and the exact active components before mapping. This page does not reuse the 120 A Pro 3EM template or provide an unverified import. The customer-platform output is optional; Edge remains the local system of record.

Models

Download
ModelsInterfaceRoute into Edge
SPEM-002CEBEU50Ethernet or site Wi-Fi; local RPC and MQTTSPEM-002CEBEU50 only. Use em1:0/em1:1 and em1data:0/em1data:1, not the three-phase EM component.
Pro 3EM 120 A, Pro EM-50 and EM Gen3Different CT limits, networking and component instancesThe 120 A Pro 3EM map is a separate guide. A similar product name does not make CTs or register blocks interchangeable.

Specifications

Choose Pro EM-50 for two monitored single-phase circuits and wired networking. The dry-contact relay is separate from measurement and is not a 50 A load switch.1

Exact model
SPEM-002CEBEU501
Measurement topology
Two single-phase measurement channels1
Current transformers
50 A maximum per measurement channel1
Local history
Up to 60 days, one-minute resolution1
Network
Ethernet and Wi-Fi1
Relay
Separate dry-contact output for external contactor control1
Installation
Indoor DIN rail; -20 to 40°C1

Interface

Documented measurements and integration boundaries for Pro EM-50.

  • Per-channel current (A), voltage (V), signed active power (W), apparent power (VA), power factor and frequency (Hz).
  • EM1Data consumed and returned active-energy counters in Wh; keep directions separate before calculating net energy.
  • Timestamped recorded data: use returned keys, periods and continuity information rather than treating a missing interval as zero.

Assessment

SPEM-002CEBEU50 only. Use em1:0/em1:1 and em1data:0/em1data:1, not the three-phase EM component. Documentation review only; no physical commissioning claim.

InteroperabilitySupported with conditions
Documented local JSON methods and MQTT status transport support a custom mapping. Validate exact model, components and installed firmware.256
AccuracySupported with conditions
Direction-aware active energy and instantaneous power support operational monitoring. CT fit, reference phase and low-load accuracy remain model-specific; no billing certification is inferred.13
SecuritySupported with conditions
The RPC protocol supports authentication; network isolation and broker TLS configuration remain the integrator’s responsibility.56
ReliabilitySupported with conditions
Local stored history supports recovery after network interruption. Handle storage horizon, gaps and counter resets explicitly.14
RuggednessSupported with conditions
Published indoor installation and ambient limits require an appropriate electrical enclosure.1
ScalabilityNot yet assessed
No verified fleet polling capacity or concurrent-client limit is established by this guide.
LifecycleSupported with conditions
Public component documentation and changelog support repeatable firmware qualification; recheck mappings after updates.27

Setup

Read one channel and its energy counters

Read-only requests against an already commissioned local meter. The numbers below are synthetic arithmetic examples, not captured device measurements.

Identity first
GET /rpc/Shelly.GetDeviceInfo: record model, firmware and profile; reject another model.
Instantaneous read
GET /rpc/EM1.GetStatus?id=0; compare voltage and act_power with the local web interface.
Energy read
GET /rpc/EM1Data.GetStatus?id=0; inspect total_act_energy and total_act_ret_energy for channel 0.
Synthetic counter difference
Consumed 125000 to 125750 Wh = 0.750 kWh; returned 8000 to 8125 Wh = 0.125 kWh; net consumed = 0.625 kWh.
History read
GET /rpc/EM1Data.GetRecords?id=0, then EM1Data.GetData with a bounded ts/end_ts window. Decode the returned keys and period; preserve gaps.

Acceptance: Accept only fresh, error-free responses for the expected component and matching local readings. A decreasing/reset counter starts a new interval; never interpret it as negative consumption.

  1. SPEM-002CEBEU50 only.

    Use em1:0/em1:1 and em1data:0/em1data:1, not the three-phase EM component.

  2. Record Shelly.GetDeviceInfo model and firmware.

    API documentation version 1.0 is the documentation edition, not a minimum firmware promise. Verify available methods and components on the installed release.

  3. Read both channel IDs independently and preserve their labels; do not interpret two channels as a three-phase meter.

  4. Have the installation checked against the exact manufacturer wiring and CT instructions.

    Match CT direction to the voltage reference and validate consumed/returned direction against a known load.

  5. Read /rpc/EM1.GetStatus?id=0 and /rpc/EM1Data.GetStatus?id=0.

    Do not convert missing, null or error-bearing values to zero. Repeat for the remaining configured channels.

  6. Use a protected LAN and the configured authentication.

    HTTP requests are not inherently encrypted; use MQTT TLS where configured and keep credentials out of URLs, logs and exported diagrams.

  7. Retrieve stored intervals with the component history API.

    Respect timestamps, returned field keys, response chunking and interruptions after power loss. Cloud access is optional for local metering.

  8. This monitoring workflow never switches the relay, resets counters, changes calibration, changes profile or writes Modbus registers.

    Those operations can alter the installation or erase history.

Common questions

Does local monitoring require Shelly Cloud?
No. The exact product supports standalone local operation. Remote access outside the LAN needs a separately secured network or cloud arrangement; it is not required for local RPC or broker-based collection.1
Can I use the Pro 3EM 120 A downloadable template?
No. This guide covers different hardware or CT scope and supplies no template. Map the exact component instances; the 3CT63 triphase and monophase profiles also expose different APIs.2
How do I calculate imported and exported energy?
Use differences between successive consumed and returned Wh counters separately, then divide by 1000 for kWh. Keep phase/channel identity, timestamps and reset boundaries. Subtract returned energy only when a net figure is wanted.4

Sources

  1. Shelly Pro EM-50 model, specifications and wiring (opens in a new tab) Shelly
  2. Shelly Pro EM-50 device components and profiles (opens in a new tab) Shelly
  3. EM1 single-channel measurements (opens in a new tab) Shelly
  4. EM1Data counters and recorded data (opens in a new tab) Shelly
  5. Shelly RPC protocol and authentication (opens in a new tab) Shelly
  6. MQTT configuration and notifications (opens in a new tab) Shelly
  7. Shelly firmware changelog (opens in a new tab) Shelly
  8. Modbus TCP component and register addressing (opens in a new tab) Shelly

Further reading

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