Introduction
This manual details the installation and configuration of the Mitsubishi Electric Thermostat Interface 2, model PAC-US445CN-1. This device facilitates the integration of third-party 24 VAC thermostats with Mitsubishi Electric HVAC systems, including the PAA unit. It ensures proper system operation by translating thermostat signals for heating, cooling, and fan control.
Key Features and Configuration
The Thermostat Interface 2 offers flexible system configuration through DIP switches (SW1 and SW2) located on the circuit board. These switches allow for adjustments to delay timers, fan speeds during thermal off periods, and operational modes for various heating and cooling stages. Specific settings are provided for different system configurations, such as single-stage or two-stage cooling and heating, and compatibility with alternate primary heating sources.
Installation and Wiring
Proper installation is crucial for safe and effective operation. The manual outlines essential safety precautions, including warnings against improper wiring, modifications, and installation in hazardous environments. It details the connection process, including wiring to the indoor unit control board (CN105) and the use of 18 AWG thermostat wire. For PAA unit installations, specific instructions are provided for mounting the interface within the control box and connecting the PAA unit accessory cable.
Usage and System Compatibility
The Thermostat Interface 2 relies on both the connected thermostat and the indoor unit's thermistors for temperature sensing. It is important to note that during normal operation with the Thermostat Interface 2, Mitsubishi Electric remote controllers are not supported as they may interfere with the system's correct functioning. The manual also specifies DIP switch settings for PAA unit compatibility, particularly regarding Mode 23 for fan speed control during cooling or heating with a heat pump.
Important Notes
- Always ensure power to the indoor unit is off before installation.
- Refer to the appropriate indoor unit installation manual for specific Mode definitions.
- The device is designed for residential environments.
- Consult Mitsubishi Electric US, Inc. for any repair or service needs.
