Document LTM0934 rev 1.03b

 

Connecting Two-wire Controllers (with internal thermostat)

Please note

2-Wire controllers are not designed to control chiller operation.

For full functionality, the Heat and Cool, and Cool Only heat pumps must use an external controller that has a SMART bus connection. Check with external controller manufacturer for more information.

 

DANGER

Failure to heed the following will result in injury or death.

 

  • Risk of Electric Shock. Deactivate power while routing wiring to control board.
  • Follow all National Electric Codes (NEC) and / or State and Local guidelines.

WARNING

Failure to heed the following may result in injury or death.

 

  • This section is only for qualified installers who are familiar with swimming pool and spa safety standards.
  • The installer must be familiar with service industry techniques.

Figure 4

 

  1. Deactivate power to heat pump.
  2. Remove heat pump electrical access panel.
  3. Route 22-gauge (minimum), 2-conductor, low-voltage wires from the controller to the low voltage side of the heat pump's electrical enclosure. Follow all National Electric Codes (NEC) unless State or Local guidelines supersede.
  4. Connect the controller wires to the microprocessor port labeled "Ext Controller" with the terminals labeled "Y" and "Z" as follows. See Figure 4.
    • Connect one wire to “Y”.
    • Connect other wire to “Z”.
    • The polarity of the wire is not important.
  5. Reattach heat pump access panel.
  6. Apply power to heat pump.
  7. Configure heat pump to accept a 2-wire external controller signal as shown.