Device identification
- Device name: Shelly Pro 3EM Switch Add-on
Short description
Shelly Pro 3EM Switch Add-on (the Device) is a galvanically isolated switch that extends the features of the Shelly Pro 3EM series of devices, allowing the control of contactors or other electrical appliances.
Main applications
- Residential
- MDU (Multi Dwelling Units - apartments, condominiums, hotels, etc.)
- Light commercial (small office buildings, small retail/restaurant/gas station, etc.)
- Agricultural (farms, barns, silos, etc.)
- Government/municipal
- University/college
Simplified internal schematics
Device electrical interfaces
Inputs
- 1 load circuit input I
Outputs
- 1 load circuit output O
Add-on interface
- Shelly proprietary serial interface
⚠ CAUTION! High voltage on the add-on interface when the Device is powered!
Safety features
- Internal temperature sensing and reporting
Supported load types
- Resistive (incandescent bulbs, small heating devices)
- Capacitive (LED light drivers, capacitor banks, electronic equipment)
- Inductive (contactors, transformers, fans, refrigerators)
User interface
Outputs
- LED indication
- Power: Red light if the power supply is connected.
- Out: Red light if the output relay contact is closed.
Specifications
| Type | Value |
|---|---|
| Physical | |
| Size (HxWxD): | 94x19x69 ±0.5 mm / 3.70x0.75x2.71 ±0.02 in |
| Weight: | 20 ±1 g / 0.70 ±0.05 oz |
| Mounting: | DIN rail, attached to a Shelly Pro 3EM |
| Screw terminals max torque: | 0.4 Nm / 4.43 lbin |
| Conductor cross section: | 0.5 to 2.5 mm² / 20 to 14 AWG (solid, stranded and bootlace lugs) |
| Conductor stripped length: | 6 to 7 mm / 0.24 to 0.28 in |
| Shell material: | Plastic |
| Color: | White |
| Environmental | |
| Ambient temperature: | -20 °C to 40 °C / -5 °F to 105 °F |
| Humidity: | 30 % to 70 % RH |
| Max. altitude: | 2000 m / 6562 ft |
| Electrical | |
| Power supply voltage AC: | N/A |
| Power supply voltage DC: | 3.3 V and 12 V (from Shelly Pro 3EM device) |
| Power consumption: | < 1 W |
| Sensors, meters | |
| Internal-temperature sensor: | Yes |
| Output circuits ratings | |
| Max switching voltage AC: | 240 V |
| Max switching voltage DC: | 30 V |
| Max switching current AC: | 2 A |
| Max switching current DC: | 2 A |
Basic wiring diagrams
| Resistive load | Inductive load and RC snubber |
|---|---|
 |  |
Legend
| Terminals | Description | Wires | Description |
|---|---|---|---|
| O | Load circuit output terminal | L | Live (110–240 V) wire |
| I | Load circuit input terminal | N | Neutral wire |
Components and APIs
Compliance
- Shelly Pro 3EM Switch Add-on multilingual EU declaration of conformity
- Shelly Pro 3EM Switch Add-on AU/NZ Certificate for Suitability
- Shelly Pro 3EM Switch Add-on UK PSTI ACT Statement of compliance