Gen3: Electrical ratings and breaker size

Last updated: October 23, 2026

This article gives the electrical limits for Mysa for Electric Baseboard Heaters Gen3. The total load of your heaters must stay in these limits.

High voltage warning

Installing this product involves handling high voltage wiring. To avoid personal injury, or death, turn off your circuit breakers and follow the proper safety precautions before proceeding.

Turn off the power before completing any electrical installation. If you are unsure that the power to your heaters is off, stop work and call an electrician.

Limits by model

Model Maximum current 120 V 208 V 240 V Breaker
Gen3 16.7 A 2,000 W 3,400 W 4,000 W Up to 30 A
V1, V2 and Lite 16 A 1,900 W 3,300 W 3,800 W 20 A (recommended)

All models operate on 120/208/240 VAC.

Gen3 specifications

  • Breaker: up to 30 A.
  • Dimensions: 145 × 99 × 48 mm (5.7 × 3.9 × 1.9 in).
  • Front plate: it glides into place.

Do not change the existing wiring. If you are not sure about your wiring, call an electrician.

Do not use the Gen3 limits for older models

Gen3 has higher limits than V1, V2 and Lite. You can install Gen3 on a breaker up to 30 A.

Do not install V1, V2 or Lite on a 30 A circuit. If your circuit is 30 A, use Gen3 or a different thermostat that has a rating for that circuit.

A 30 A breaker is not a wattage rating. The total load of your heaters must stay in the wattage limit for your model.

Multiple heaters on one circuit

One Mysa thermostat can control multiple heaters if all these conditions are true:

  • The total wattage of all the heaters is less than the limit for your voltage. Refer to the table above.
  • The total current is less than the maximum current for your model: 16.7 A for Gen3, or 16 A for V1, V2 and Lite.
  • All the heaters are on the same circuit.

Add the wattage of all the heaters on the circuit. Make sure that the total is in the limits.

Before you install

  1. Turn off the breaker. Make sure that the power to your heaters is off.
  2. Look at the rating plate on each heater to find its wattage. Find the size of the breaker.
  3. Make sure that the total wattage is less than the limit for your voltage.
  4. If you are not sure about the breaker or the load, call an electrician.

Get support

Send an email to install@getmysa.com.