American Standard HVAC YSC120A Manual

The American Standard YSC120A is a high-efficiency, single-stage, scroll compressor condensing unit designed for residential and light commercial applications. It features R-410A refrigerant, weather-resistant construction, sound reduction technology, compatibility with American Standard matched indoor units, diagnostic LED indicators, and corrosion-resistant coil coating. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

Features at a Glance

Key components: Scroll compressor, Weather-resistant cabinet, Liquid and suction line service valves, Diagnostic LED, High and low pressure switches, Corrosion-resistant coil.

Installation

Unpack and inspect contents. Place on stable, level pad.

1. Location: Install on solid, level concrete pad or approved mounting system. Ensure minimum clearances (24" on all sides, 48" above).
2. Electrical: Connect proper gauge wiring from disconnect to unit terminals (L1, L2). Follow local electrical codes.
3. Refrigerant Lines: Connect pre-charged, dehydrated lines to liquid and suction valves. Braze connections using nitrogen purge.
4. Condensate Drain: Ensure proper drainage from indoor unit.
5. Start-up: Evacuate system, open service valves, check charge, and verify operation.

WARNING! Installation must be performed by a qualified HVAC technician. Disconnect all power before servicing. Use proper personal protective equipment.

First-Time Setup

After installation, perform initial setup and verification.

1. Power Verification: Ensure correct voltage at unit (208/230V single-phase).
2. Thermostat: Install compatible thermostat (American Standard recommended). Set to OFF mode.
3. System Check: Close service valves, evacuate to 500 microns, open valves fully.
4. Charge Verification: Check subcooling (for TXV systems) or superheat (for fixed orifice). Adjust charge if necessary.
5. Test Operation: Set thermostat to COOL mode, lower setpoint below room temperature. Verify compressor and fan operation.
6. Airflow: Check indoor airflow (typically 400 CFM per ton). Adjust blower speed if needed.

CAUTION! Do not operate without proper refrigerant charge. Overcharge or undercharge can damage compressor.

Specifications

• Model: YSC120A
• Cooling Capacity: 2-5 tons (varies by model)
• Refrigerant: R-410A
• Electrical: 208/230V, 1 phase, 60 Hz
• Compressor: Scroll, single-stage
• Sound Level: As low as 72 dB(A)
• Operating Range: 55°F to 115°F outdoor temperature
• Maximum Working Pressure: High side 600 psig, Low side 200 psig
• Dimensions: Approx. 35" W x 35" D x 31" H (varies by size)
• Shipping Weight: 180-250 lbs (varies by size)

Controls and Settings

Primary control via thermostat. Unit includes internal safeties and diagnostic LED.

Thermostat Settings: COOL, HEAT (with heat pump models), FAN (ON/AUTO), temperature setpoints.

Unit Controls: Contactor, run capacitor, overload protection. Diagnostic LED flashes codes for troubleshooting.

LED Flash Codes: 1 flash = Low pressure, 2 flashes = High pressure, 3 flashes = Low voltage, 4 flashes = High voltage, 5 flashes = Compressor overload, Continuous on = Normal operation.

Adjustments: Charge adjustment via service valves, fan speed adjustment on some indoor units.

Connecting Components

Connect to indoor coil/air handler, thermostat, and power supply.

1. Indoor Unit: Connect refrigerant lines, condensate drain, and low voltage control wires.
2. Thermostat: Connect R (24V), C (common), Y (compressor), G (fan) wires. Add O/B for heat pump models.
3. Power: Connect line voltage (L1, L2, ground) through disconnect to unit terminals.
4. Line Set: Use properly sized copper tubing (consult sizing chart). Insulate suction line.

Tip: Label all wires before disconnecting. Take photos of original wiring for reference.

Operation

Normal operation via thermostat.

1. Cooling Mode: Set thermostat to COOL, set desired temperature. Compressor and fan will cycle on/off to maintain temperature.
2. Fan Mode: Set to ON for continuous fan, AUTO for fan with compressor.
3. Shutdown: Set thermostat to OFF to stop operation.
4. Seasonal: For winter, cover unit (optional) to protect from debris. Do not operate in cooling mode below 55°F outdoor temperature.

WARNING! Do not attempt to operate if unusual noises, smoke, or burning smells are detected. Turn off power immediately and contact technician.

Maintenance

Regular maintenance ensures efficiency and longevity.

1. Monthly: Check air filter (indoor unit), replace if dirty.
2. Seasonal: Clean outdoor coil with gentle water spray (power off). Remove debris from around unit.
3. Annual: Professional inspection: check refrigerant charge, electrical connections, capacitor, contactor, and safety controls.
4. Condensate Drain: Flush annually with bleach/water solution to prevent algae.

CAUTION! Turn off all power before performing any maintenance. Do not use pressure washer on coil.

Care & Cleaning

Keep unit clean for optimal performance.

Outdoor Unit: Clean coil fins with soft brush or low-pressure water. Straighten bent fins with fin comb. Keep area clear of vegetation (minimum 24" clearance).

Indoor Unit: Replace filter regularly. Clean evaporator coil if accessible (professional service).

CAUTION! Do not use harsh chemicals or abrasive cleaners. Do not bend fins excessively.

Regulatory Information

UL listed. Complies with U.S. safety standards. Contains refrigerant R-410A. EPA Section 608 certified technicians required for service. Manufactured to meet DOE efficiency standards. For support, contact American Standard Customer Care at 1-800-628-4516 or visit www.americanstandardair.com.

Troubleshooting

Reset: Turn thermostat to OFF, turn off power at disconnect for 5 minutes, restore power, set thermostat to COOL.

Service: 1-800-628-4516; www.americanstandardair.com