American Standard HVAC Odyssey TWA2404 D Manual

The American Standard Odyssey TWA2404 D is a high-efficiency, variable-speed air handler designed for use with compatible heat pump systems. It features a durable galvanized steel cabinet, a multi-speed ECM blower motor, and integrated control board for precise temperature and humidity management. Below are key sections covering safety, features, installation, setup, operation, maintenance, and troubleshooting.

Features at a Glance

Key components: Galvanized steel cabinet, ECM blower motor, integrated control board, refrigerant coil access panel, condensate drain connection, and low-voltage terminal strip.

Feature	Description
Cabinet Construction	Heavy-duty galvanized steel with baked enamel finish
Blower Motor	Variable-speed Electronically Commutated Motor (ECM)
Control Board	Integrated for system communication and fault diagnostics
Airflow Capacity	Up to 4 tons (48,000 BTU/h) cooling capacity
Filter Rack	Standard 1-inch or optional 2-inch media filter slot
Refrigerant Connections	Quick-connect fittings for field-installed coil
Electrical Requirements	240V AC, 60Hz, dedicated circuit
Communication Interface	Compatible with American Standard communicating thermostats
Sound Insulation	Internal insulation for reduced operational noise
Drain Connection	3/4-inch PVC condensate drain port

Installation Requirements

Unpack and inspect unit for shipping damage. Ensure installation site meets requirements.

1. Location: Install in a clean, dry, indoor space such as a utility room, basement, or conditioned attic with adequate service clearance.
2. Mounting: Unit must be level. Use vibration isolation pads if mounting on suspended floor.
3. Ductwork: Connect supply and return ducts securely. Seal all joints with mastic or UL 181-approved tape.
4. Electrical: Connect to dedicated 240V, 60Hz circuit with appropriate overcurrent protection as per local codes.
5. Condensate Drain: Install 3/4-inch PVC line with proper trap and slope to drain. Consider auxiliary drain pan in attic installations.
6. Refrigerant Lines: Connect to matching outdoor heat pump unit. Brazing must be done with nitrogen purge to prevent oxidation.

WARNING! Installation must be performed by a qualified HVAC technician in accordance with all national and local codes. Disconnect all power before servicing.

First-Time Setup & Commissioning

After mechanical installation, power on the system and perform initial configuration.

1. Power Up: Restore power to the unit. The control board LED should illuminate.
2. Thermostat Configuration: Install compatible communicating thermostat. Follow thermostat manual for initial setup and system identification.
3. Blower Settings: Configure default CFM for heating and cooling modes via DIP switches on the control board (refer to wiring diagram).
4. System Check: Initiate a test cycle from the thermostat. Verify correct airflow from all supply vents, listen for unusual noises, and check condensate drain operation.
5. Final Inspection: Ensure all access panels are secure and the installation area is clean.

CAUTION! Do not jumper R to G to run the blower continuously during commissioning, as it may bypass critical safeties. Use thermostat fan settings.

Technical Specifications

• Model: TWA2404 D
• Product Series: Odyssey Variable-Speed Air Handler
• Nominal Cooling Capacity: 4 Tons (48,000 BTU/h)
• Nominal Heating Capacity: Matched to connected heat pump
• Voltage: 208/240V AC, 1-Phase, 60 Hz
• Motor Type: Variable-Speed ECM
• Airflow Range: 350 - 1600 CFM (configurable)
• Maximum External Static Pressure: 0.8 inches w.c.
• Filter Type: 1" throw-away or 2" media (field supplied)
• Refrigerant Type: R-410A
• Operating Ambient Temperature: 45°F to 120°F
• Cabinet Dimensions (HxWxD): Approx. 49" x 21" x 21"
• Shipping Weight: Approx. 150 lbs

Controls & Configuration

Primary control is via the integrated board and communicating thermostat. No user-serviceable controls are on the cabinet.

Control Board LED Indicators: Flashing patterns indicate system status (normal operation, fault mode, waiting for call). Refer to fault code chart inside the access panel.

DIP Switch Bank (S1):

• Switches 1-4: Set cooling airflow (CFM/ton).
• Switches 5-8: Set heating airflow (CFM/ton).
• Default factory setting is typically "Standard" airflow.

Thermostat Settings (via Interface):

• System Mode: Heat, Cool, Auto, Off.
• Fan Mode: Auto, On (Continuous).
• Advanced Settings: Dehumidification mode, fan delay on cooling, variable-speed profiles.

System Connections

Low-Voltage Connections (Terminal Strip): R, C, G, Y1, Y2, O/B, W1, W2, S1, S2, etc., for thermostat and outdoor unit communication.

Line Voltage Connections (Junction Box): L1, L2, Ground for 240V power.

1. Turn OFF main power at the breaker panel.
2. Remove access panel to the control board and junction box.
3. Route low-voltage thermostat cable and connect wires to the corresponding terminals on the strip as per the wiring diagram.
4. Connect line voltage wires in the separate junction box.
5. Ensure all connections are tight and wires are secured with cable clamps.

Tip: Use a voltmeter to confirm power is OFF before touching any terminals. Verify all connections against the diagram provided on the unit.

Operating Modes

The unit operates based on signals from the thermostat.

1. Cooling Mode: Thermostat calls for cooling (Y signal). Blower ramps up to preset cooling CFM. Reversing valve on heat pump is energized (O signal).
2. Heating Mode: Thermostat calls for heating (Y & W signals). Blower ramps up to preset heating CFM. Reversing valve is de-energized.
3. Fan-Only Mode: Thermostat calls for indoor fan (G signal). Blower runs at a continuous low speed or as configured.
4. Dehumidification Mode: On a call for cooling with high humidity, the blower may run at a lower speed to enhance moisture removal.
5. System Shutdown: Thermostat set to OFF. All control power remains active to the air handler.

WARNING! Do not attempt to switch system modes rapidly. Allow several minutes between mode changes for system pressure equalization.

Maintenance Procedures

Monthly: Inspect and replace air filter as needed. A dirty filter restricts airflow and reduces efficiency.

Seasonally (Before Cooling/Heating Season):

1. Turn OFF power to the unit.
2. Remove filter and inspect the evaporator coil for dirt or debris. Clean gently with a soft brush if accessible.
3. Inspect the condensate drain line and trap. Clear any blockages and pour a cup of water to ensure proper drainage.
4. Check all electrical connections for tightness.
5. Listen for unusual noises when restarting.

Annually (Professional Service Recommended): Have a qualified technician inspect the blower wheel, motor, electrical components, and system performance.

CAUTION! Always disconnect power before performing any maintenance. Do not use water or liquid cleaners on electrical components.

Regulatory & Compliance

This product complies with applicable U.S. safety and performance standards. It is designed for use in the United States and Canada. The installation must comply with:

• National Electrical Code (NFPA 70)
• Local building and mechanical codes
• UL Standard 1995
• ASHRAE Standard 90.1 for energy efficiency

Copyright © American Standard Heating & Air Conditioning. All trademarks are property of American Standard. For technical support and warranty service, contact your installing dealer or visit www.americanstandard.com.

Troubleshooting Guide

Symptom	Possible Cause	Corrective Action
Unit will not power on	Circuit breaker tripped, disconnect switch off, loose wiring	Check and reset breaker. Ensure disconnect is ON. Inspect line voltage connections.
No airflow from vents	Dirty filter, faulty thermostat, blower motor issue	Replace filter. Verify thermostat settings and G wire connection. Listen for blower motor hum; if present, check for obstructed wheel.
Insufficient cooling/heating	Dirty filter/coil, low refrigerant, incorrect airflow setting	Clean filter and coil. Have technician check refrigerant charge. Verify DIP switch airflow settings.
Water leakage from unit	Clogged condensate drain, disconnected drain line	Clear drain line and trap. Ensure line is properly connected and has correct slope.
Unusual noises (rattling, squealing)	Loose access panel, debris in blower, failing motor bearings	Secure all panels. Inspect and clean blower wheel. If noise persists, motor may need professional service.
Control board LED flashing error code	System fault detected (pressure, sensor, communication)	Count flashes, refer to fault code chart inside unit. Common codes indicate loss of communication with thermostat or outdoor unit.

Reset: For lockout conditions, turn system OFF at thermostat for 5 minutes, then back ON. If problem persists, call for service.

Service: Contact your authorized American Standard dealer. For product information: www.americanstandard.com.