This article applies to:

Danger: The installation of high voltage equipment should be performed by a qualified electrician. Please ensure that you comply with local electrical codes and regulations. Improper installation can lead to device failure and even cause a fire. Damage to thermostat due to improper installation is not covered under warranty.

Connect your Mysa Smart Thermostat using supplied wire nuts. Click here to learn how to properly use a wire nut.

Please verify which version of Mysa you are installing. If your Mysa has four wires then it is Mysa-V1-0. If your Mysa has three wires, then it is Mysa-V1-1. Functionally, these thermostats are the same, just with slightly different wiring.

Mysa-V1-1

A) Connect Mysa’s red L2 wire to the second phase leg of the circuit - L2 (usually 2, red wires).
B) Connect Mysa’s black L1 wire to the supply wire - L1 (usually black) coming from the electrical panel.
C) Connect Mysa’s black load wire to the load wire (usually black) going to the heater.

In summary:

	Mysa L2			Second Phase Leg (L2)
	Mysa L1			Supply Wire (L1)
	Mysa Load			Load Wire

Two Heaters

In the case that you have two heaters connected to a single thermostat you can follow the wiring guide below:

Mysa-V1-1

A) Connect Mysa’s red L2 wire to the second phase leg of the circuit - L2 (usually 2, red wires).
B) Connect Mysa’s black L1 wire to the supply wire - L1 (usually black) coming from the electrical panel.
C) Connect Mysa’s black load wire to the two load wires (usually black) going to the heaters.

In summary:

	Mysa L2			Second Phase Leg (L2)
	Mysa L1			Supply Wire (L1)
	Mysa Load			Load Wire

For more detailed instructions or different wiring setups,
download the Mysa App, tap on “Install & Support”, then “Install”.

Important

The supply and load wires are not interchangeable. If you are unsure which of the two wires is the supply or load wire, simply try one configuration. If Mysa’s display doesn’t light up after finishing the installation, swap the supply and load wires.

Mysa-V1-0
A) Connect Mysa’s white wire to the second phase leg of the circuit - L2 (usually red).

In summary: 

	Mysa White			Second Phase Leg (L2)
	Mysa Black			Supply Wire (L1)
	Mysa Red			Load Wire
	Mysa Green			Group/Copper