Trane ASYSTAT666C Thermostat Operation Manual

The Trane ASYSTAT666C is a programmable zone sensor thermostat designed for use with Trane constant volume (CV) and heat pump (HP) units, including 3-25 ton packaged heat/cool systems and 3-20 ton packaged heat pump units. It features a 7-day programmable schedule with four periods per day, temporary overrides, morning warm-up functionality, and communication with the Unit Control Module (UCM) via the Network Sensor Bus (NSB). Ideal for zoned HVAC control in commercial/residential applications, it provides efficient temperature management and status indicators. Below are the key specifications and operation instructions.

1. Key Specifications 2. Operation Instructions 2.1. Initial Setup 2.2. Home Screen Navigation 2.3. Scheduling and Presets 2.4. Settings Screen 2.5. Advanced Features 2.6. Troubleshooting 3. Installation Instructions 3.1. Pre-Installation 3.2. Wiring Diagrams 3.3. Configuration Options 4. Calculation Tool

Key Specifications

Type: Programmable zone sensor thermostat for remote panel with NSB
Compatibility:
- 3-25 ton packaged heat/cool units (ASYSTAT666C), 3-20 ton packaged heat pump units
- 27.5-50 ton packaged rooftop units
- Communicates with UCM via terminals for HEAT, COOL, SYSTEM ON, SERVICE
Power:
- 24 VAC at terminals 11/14; 22-32 VDC for communications (terminals 11/12)
Temperature Range: Zone temperature display; morning warm-up activates if 2°F below setpoint
Dimensions: Compact wall-mount design; mounts on interior wall or 2x4 handy box
Features:
- 7-day programming with 4 periods/day (Occupied/Unoccupied)
- Temporary overrides, status indicators (flashing colon for system ON, TEST/SERVICE icons)
- Morning warm-up, supply air temperature sensor option
- Auxiliary relay support; max wire lengths (e.g., 18 AWG up to 1000 ft)
Compliance: Designed for professional HVAC installation

Operation Instructions

Initial Setup

1. Power On: After installation, displays Normal Run State Screen showing zone temperature and setpoints.
2. Enter Option Menu: Press PROGRAM and MODE keys simultaneously for 4 seconds to configure initial settings.
3. Verify: Check clock, enable morning warm-up (default: enabled).

Home Screen Navigation

1. Normal Run State: Displays zone temperature, heat/cool setpoints, time, day, and status icons.
2. Controls: Use UP/DOWN arrows to navigate, TIME +/- for adjustments, DAY for toggling.
3. Indicators: Flashing colon for system ON; override screen for temporary changes.

Scheduling and Presets

1. Access Programming Menu: Press PROGRAM; set 7-day schedule with 4 periods (start time, occupied/unoccupied, setpoints, supply air).
2. Preset Periods: Occupied/Unoccupied modes with heat/cool setpoints; supports warmup during transitions.
3. Exit: Hold PROGRAM for 2 seconds.

Settings Screen

1. Option Menu: Press PROGRAM + MODE for 4 sec; use arrows to select options (e.g., morning warm-up: 0=disabled/1=enabled).
2. Temporary Override: Press HOLD TEMP; set new temperature, duration (hours/days via TIME +/- and DAY toggle).
3. Clock Format: 12/24 hour; exit by pressing PROGRAM for 2 sec.

Advanced Features

1. Morning Warm-Up: Automatically heats if zone is 2°F below setpoint during unoccupied-to-occupied transition.
2. Supply Air Sensor: Enable/disable via options for monitoring.
3. Test Mode: Flashing TEST icon; SERVICE icon for alerts via terminal 10.
4. Auxiliary Relay: Optional for additional control.

Troubleshooting

Display Not On: Check 24 VAC at terminals 11/14; verify terminal block position.
No UCM Communication: Verify 22-32 VDC at terminals 11/12; check wiring.
Unit Not Responding: Confirm connections to UCM terminals 7-10; test mode.
Schedule Issues: Re-enter programming menu; check clock settings.

Installation Instructions

Warning: Installation by experienced HVAC technicians only. Disconnect power before wiring. Follow safety cautions to avoid equipment damage.

Pre-Installation

Mount on interior wall near return air grille, ~5 ft above floor for free air circulation.
Prepare 4 wires (HEAT, COOL, SYSTEM ON, SERVICE) from UCM; optional 3 wires for auxiliary relay.
Wire sizes: See Table 1 (e.g., 18 AWG max 1000 ft).

Wiring Diagrams

Connect to UCM and power source:

Terminal	Connection
7	HEAT (to UCM)
8	COOL (to UCM)
9	SYSTEM ON (to UCM)
10	SERVICE (to UCM)
11/14	24 VAC Power
11/12	Communications (22-32 VDC)

Note: Use convention for UCM connections; optional auxiliary relay wiring.

Configuration Options

Mount sub base with screws (on wall or 2x4 box); hook ZSM top tabs and lock.
Power up for initial screen.
Enter Option Menu: Set morning warm-up, supply air sensor, clock format per Table 3.
Program schedule via Programming Menu.

Calculation Tool

Estimate monthly energy savings from temperature setback during unoccupied periods (assumes 0.3 kWh per °F per hour; 2°F morning warm-up threshold factored). Savings = ΔT * unoccupied hours * factor * cost.