Standard smart plugs and switches are rated for 120V/15A circuits. If you need to control a 220V or 240V appliance — such as an electric dryer, air conditioner, water heater, hot tub, or EV charger — you need a device specifically designed for high-voltage circuits.
Common 240V Appliances That Can Be Made Smart
- Electric dryers and ranges
- Window and portable air conditioners (230V models)
- Electric water heaters and tank heaters
- Hot tubs and pool heaters
- Level 2 EV chargers (NEMA 14-50 or hardwired)
- Workshop tools: table saws, air compressors, dust collectors
Best 240V Smart Controllers
1. Shelly Plus 1PM — Best Overall for DIY
Rated for up to 240V AC and 16A (3,500W). Installs inside a junction box and integrates natively with Home Assistant, Alexa, Google Home, and Apple HomeKit. Real-time power monitoring built in. Under $20.
2. Sonoff POW R316 — Best for Energy Monitoring
Handles up to 240V/16A with high-accuracy real-time energy monitoring. Supports Wi-Fi and integrates with eWeLink, Alexa, and Google Home. Can be flashed with Tasmota for full local control.
3. Emporia Vue 2 — Best for Monitoring
A whole-home energy monitor that clamps onto individual circuits in your breaker panel including 240V circuits. Integrates with Home Assistant. Ideal for monitoring EV charging, water heaters, and dryers.
4. Sonoff ZBMINI-L (Zigbee, 240V, No Neutral)
Supports up to 240V/10A without a neutral wire. Pairs directly with a Zigbee coordinator for fully local control. Popular for boilers and water pumps in European home automation setups.
Critical Safety Requirements
- Always turn off the breaker before any wiring work and verify power is off with a non-contact tester
- Match the relay current rating to your load — never exceed it
- Use correct wire gauge: 10AWG for 30A, 8AWG for 40 to 50A
- Check local codes — many jurisdictions require a licensed electrician for 240V modifications
- 240V is lethal — hire an electrician if you are not confident