How do I wire up Mysa?

Warning: 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.

 

First, determine if you're installing Mysa to control a 120V or 240V heater(s). If you need help determining this, check out this article. Also, this article on identifying wires in your gang box may help.

Always ensure that the power is turned off.

240V Installations

Your gang box typically has the following wires:

  • 1 black live wire (L1)
  • 2+ red live wires (L2)
  • 1+ black heater load wire

Install Mysa:

  1. Connect Mysa's black wire to the black live wire (L1) coming from the electrical panel (usually top of the gang box)
  2. Connect Mysa's white wire to the red live wires (L2)
  3. Connect Mysa's red wire to one or more heater load wires (Heater Load) connecting to the heater (usually bottom of the gang box)
  4. Connect Mysa's green wire to the ground wire (bare copper or green) or grounding screw in the gang box

240V_Wiring_Diagram.png

120V Installations

Your gang box typically has the following wires:

  • 1 black live wire (L)
  • 2+ white neutral wires (N)
  • 1+ black heater load wire

Install Mysa:

  1. Connect Mysa's black wire to the black live wire(s) (L1) coming from the electrical panel (usually top of the gang box)
  2. Connect Mysa's white wire to the white neutral wires (N)
  3. Connect Mysa's red wire to one or more heater load wires (Heater Load) connecting to the heater (usually bottom of the gang box)
  4. Connect Mysa's green wire to the ground wire (bare copper or green) or grounding screw in the gang box

120V_Wiring_Diagram.png

If you have more than 4 wires in your gang box (common case):

  • Check out this article for identifying all the wires in your gang box
  • If you have multiple supply wires (L1), connect them all to Mysa's black wire
  • Always connect all the red (L2) or white (N) wires in the gang box to Mysa's white wire
  • Connect all black heater load wires to Mysa's red wire

 

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