Shelly Pro Cbs

About Shelly Pro CB products

A circuit breaker is an electrical safety device that automatically interrupts current when a circuit is overloaded or develops a short circuit. A smart circuit breaker adds monitoring and remote control features, letting users track breaker status and input voltage, and manually trip the breaker when needed to protect connected equipment.

Shelly smart miniature circuit breakers (MCBs) are especially useful in maintenance and control applications where early notification of a faulty circuit is essential. Power to equipment can be interrupted remotely, either in an emergency or as part of planned maintenance.

With flexible firmware and LAN connectivity, Shelly MCBs give professional integrators more options for tailored end-customer solutions. They can operate standalone on a local LAN and/or Wi-Fi network, and also integrate with cloud-based home automation services via MQTT, HTTP, and WebSocket. All inbound connections support TLS for secure communication.

Each Device has an embedded web interface for real-time monitoring and control, as well as configuration of settings.

Main features

• Protect electrical installation from overload. The Device breaks the circuit in the event of short circuit or overcurrent.

• Remote control with safety switch. Turn the Device on or off remotely. The function can be disabled through a mechanical safety switch on the front panel of the Device.

• Remote turning on is only possible if the Device was previously turned off remotely. This feature is disabled if the circuit breaker has tripped or if the device has been manually turned off.

• Monitor line voltage: The Device prevents overvoltage or undervoltage conditions for downstream equipment.

• Audit log: All on or off events and their sources (manual, remote, or tripping) are persisted in device memory with a timestamp and can be reviewed.

• DIN rail mountable.

• Ethernet: Provides professional integrators with increased reliability and security.

• Bluetooth: The Device complies with the Bluetooth standard and can be controlled over Bluetooth.

• BLE Gateway: Facilitates communication between BLE and Wi-Fi-enabled devices.

• Wi-Fi: The Device can connect to a wireless network.

• Wi-Fi Range extender: Repeats the Wi-Fi signal to extend its range.

• Scripting: Allows creating automation scenarios through scripts.

• Basic Schedules: Supports weekly schedules and routines.

• Аdvanced Schedules: Supports detailed schedules and routines throughout the year with a broad range of time adjustments from seconds to months.

• Webhooks: Supports automation through lightweight, event-driven communication with other devices in the same network or local actions.

• Compatibility: Highly compatible with 3rd party home automation systems.

• No need for hub: Ready for use locally or remotely via Shelly Smart Control or 3rd Party systems.

• KVS (Key-value storage): The KVS service provides a basic persistent storage of key-value pairs.

• Virtual components: A special set of components that do not exist in the device initially and are created dynamically by the user.

Use cases

• Electrical safety of homes and business: Protect appliances and property by reducing risk of malfunctions and fires due to system overloads or over/under voltage.

• Proactive response: Get notified immediately if a circuit fails. Shelly integration options and cloud notifications allow for solutions for fast and reliable notifications.

• Safety improvements: Remotely disconnect power to affected areas in cases of floods, fires, earthquakes, etc.

Integrations

Simplified internal schematics

Device electrical interfaces

Connectivity

• Ethernet

• Wi-Fi

• Bluetooth

Safety function

• Overcurrent protection

  • Magnetic and temperature triggered

  • Type C disconnection curve

• Overvoltage and undervoltage protection (disabled by a safety switch)

  • MCU controlled

  • User customizable

Supported load types

Any up to the rated current of the circuit breaker.

User interface

Inputs

• Lever to manually connect or disconnect the circuit breaker.

• Reset button

  • Press and hold for 5 seconds to enable Device access point and Bluetooth connection.

  • Press and hold for 10 seconds to factory reset the Device.

• Safety switch to disable the MCU control over the circuit breaker.

Outputs

• Front LED (varies)

  • Blue light indicator will be on if in AP mode.

  • Red light indicator will be on if in STA mode and not connected to a Wi-Fi network.

  • Yellow light indicator will be on if in STA mode and connected to a Wi-Fi network. Not connected to Shelly Cloud or Shelly Cloud disabled.

  • Green light indicator will be on if in STA mode and connected to a Wi-Fi network and to the Shelly Cloud.

  • The light indicator will be flashing Red/Blue if OTA update is in progress.

• LAN LED (green): Green light indicator will be on if LAN is connected.

• Mechanical state indicator

  • Red color indicates connected state (lever is up)

  • Green color indicates disconnected state (lever is down)

Specifications

Basic wiring diagrams

Components and APIs

• This device

• All Shelly devices and services

Compliance

• Shelly Pro CB multilingual EU declaration of conformity 297 2026-06-16.pdf

• Shelly Pro CB UK PSTI ACT statement of compliance 297 2026-06-16.pdf

• Shelly Pro CB UKCA declaration of conformity 297 2026-06-16.pdf

Printed user guide

• Shelly Pro CBs multilingual printed user and safety guide.pdf