Trane 3H/2C Thermostat Operation Manual

The Trane 3H/2C Thermostat is a programmable wall-mounted control designed for multi-stage heat pump systems with up to 3 stages of heat (including auxiliary/emergency) and 2 stages of cooling. It features an LCD display, scheduling capabilities, remote sensor support, and configuration options for efficient HVAC control. Available in programmable (BAYSTAT150A) and non-programmable (BAYSTAT155A) versions. 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 and Configuration 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/Non-programmable 3-Heat/2-Cool thermostat
Compatibility:
- 3H/2C heat pump with auxiliary/emergency heat
- Conventional or heat pump systems up to 3 stages heat, 2 stages cool
- Remote sensors (S1/S2), economizer/TOD (A terminal), emergency indicator (L)
Power:
- 24 VAC (18-32 VAC rms), 50/60 Hz, <1 VA
- Battery backup for time/date (5 days); non-volatile memory for config/schedule
Temperature Range: Heating: 40°F-90°F; Cooling: 50°F-99°F; Accuracy: ±1.4°F
Dimensions: Programmable: 4.7" H x 3.25" W x 1.08" D; Non-programmable: 4.7" H x 3.07" W x 1.1" D
Features:
- LCD display with mode/fan/time indicators
- Scheduling (programmable: 2/4 periods, 5+1+1/7-day)
- Auto changeover with 2-9°F deadband
- Compressor/aux lockout, extended fan time
- Lockout security, cycling rates (1-10 CPH heat, 1-5 cool)
Compliance: UL listed, plenum suitable, FCC Part 15

Operation Instructions

Initial Setup

1. Power On: Displays firmware version, then home screen or error code.
2. Configure: Hold config button 3 sec to enter mode; set system type (11 for programmable 3H/2C).
3. Time Set (Programmable): Hold ↑+↓+Mode+Fan+Prog 3 sec; adjust hour/minute.

Home Screen Navigation

1. Display: Current temperature, mode (Heat/Cool/Auto/Off/Emergency), fan (Auto/On), time/period (programmable).
2. Toggle Views: Hold ↑+↓ 3 sec to cycle: temp, setpoint, outdoor (if sensor).
3. Adjust: Press ↑/↓ for setpoints; Mode/Fan buttons to change.

Scheduling and Presets

(Programmable Only) 1. Enable: Press Prog; select days/periods.
2. Periods: 2 or 4 per day (e.g., morning 70°F heat/78°F cool; defaults vary by option).
3. TOV Override: Adjust ↑/↓, then set duration (up to 4 hrs), fan, occupancy.
4. Non-Programmable: Manual setpoints only; no scheduling.

Settings and Configuration

1. Access: Hold config 3 sec; scroll options with arrows.
2. Key Settings: Temp resolution, clock format, deadband (2-9°F), CPH rates, lockouts.
3. Lock: In mode, hold ↑+↓ 4 sec (icon shows).
4. Exit: Press config or wait 10 min.

Advanced Features

1. Remote Sensor: Config to display/use outdoor temp for lockouts (e.g., compressor below 45°F).
2. Aux Heat: Comfort/economy mode (non-programmable).
3. Economizer: A terminal for TOD/cool calls.
4. Extended Fan: 90 sec post-heat, 40 sec post-cool.
5. Emergency Heat: Manual activation; L terminal indicator.

Troubleshooting

Error E0: Thermistor fault (<14°F or >122°F); check sensor, cycle power.
Error E4: Voltage out of range; verify 18-32 VAC.
No Operation: Check wiring, config options, CPH settings.
Schedule Issues: Verify time/date; reset defaults if needed.

Installation Instructions

Warning: Qualified personnel only. Disconnect power before wiring. Max wire resistance 2.5 ohms.

Pre-Installation

Mount 48-54 in. above floor, away from drafts/sun/heat.
Wire: 18-22 AWG; max length 385 ft to HVAC.
Tools: Level, drill, screwdriver.

Wiring Diagrams

For 3H/2C Heat Pump with Aux (jumper Rc/R if single transformer):

Terminal	Connection
Rc/R	24V Power
Y/Y2	Compressor Stages 1/2
O/B	Changeover Valve (O in Cool)
W/Aux	Aux Heat
W2/E	Emergency/Aux Heat
G	Fan
C	Common
L	Emergency Indicator
A	Economizer/TOD
S1/S2	Remote Sensor

Note: Programmable has two terminal blocks; see manual figures for dual transformer.

Configuration Options

Enter config mode post-install.
Set system: 11 (programmable 3H/2C HP w/aux).
Adjust CPH: e.g., Stage 1 Heat 5, Compressor 3.
Deadband: 3°F default; lockouts as needed.
Save and exit.

Calculation Tool

Estimate stage 1 runtime percentage based on temperature difference (ΔT) and cycles per hour (CPH). Assumes duty cycle = ΔT / 20 (capped at 100%); runtime % = duty cycle * 100.