American Standard HVAC Mitsubishi Electric NAXSKS15A112A Series Manual

The American Standard HVAC Mitsubishi Electric NAXSKS15A112A Series is a high-efficiency, multi-zone ductless mini-split heat pump system designed for residential and light commercial applications. It features inverter-driven compressor technology for precise temperature control, compatibility with multiple indoor units, quiet operation, and advanced filtration. The system provides both heating and cooling with high SEER and HSPF ratings, includes wireless remote control, built-in diagnostics, and supports various installation configurations. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

Features at a Glance

Key components: Outdoor Condensing Unit (NAXSKS15A112A), Compatible Indoor Wall-mounted/Ceiling Cassette Units, Wireless Remote Controller, Refrigerant Piping, Communication and Power Cabling.

Installation Guidelines

Unpack and inspect all components. Select a suitable location for the outdoor unit with proper clearance.

1. Outdoor Unit Placement: Install on a stable, level pad or mounting bracket with minimum clearances as specified (typically 12" top, 6" sides, 24" front).
2. Refrigerant Piping: Connect pre-charged refrigerant lines between outdoor and indoor units. Ensure flares are properly made and connections are leak-tight.
3. Electrical Connections: Connect power supply (208/230V, 1-phase) to the outdoor unit disconnect. Connect communication wiring between outdoor and indoor units.
4. Drain Line Installation: Connect condensate drain line from indoor unit to an appropriate drain or condensate pump.
5. Vacuum & Dehydration: Evacuate the refrigerant lines to remove moisture and non-condensables before releasing refrigerant charge.

WARNING! Installation must be performed by a qualified HVAC technician in accordance with all local codes and regulations. Incorrect installation can cause injury, property damage, or system failure.

First-Time Setup & Commissioning

After installation, power on the system and perform initial setup.

1. Power On: Turn on circuit breaker to outdoor and indoor units.
2. Remote Control Setup: Insert batteries into wireless remote. Point remote at indoor unit signal receiver.
3. Test Operation: Set system to COOL mode, desired temperature below room temp, and high fan speed. Verify cold air discharge and condensate drainage.
4. Test Heating: Set system to HEAT mode, desired temperature above room temp. Verify warm air discharge after defrost cycle initialization (if needed).
5. Check Refrigerant Charge: Using manifold gauges, verify subcooling/superheat per manufacturer's specifications under stable conditions.
6. Configure Optional Settings: Set clock, timer functions, and user preferences via remote control.

CAUTION! Do not operate the system if refrigerant leaks are suspected. Contact a qualified technician immediately.

Technical Specifications

• Model Series: NAXSKS15A112A (Outdoor Unit)
• Power Supply: 208/230V, 1 Phase, 60 Hz.
• Cooling Capacity: 15,000 BTU/h (Approx.)
• Heating Capacity: 16,000 BTU/h (Approx.)
• SEER Rating: Up to [Insert SEER] (High Efficiency)
• HSPF Rating: Up to [Insert HSPF] (High Efficiency)
• Refrigerant Type: R-410A
• Refrigerant Charge (Pre-charged): [Insert Charge] oz (for specified piping length)
• Maximum Piping Length: [Insert Length] ft (Outdoor to Indoor)
• Maximum Height Difference: [Insert Height] ft (Outdoor above/below Indoor)
• Sound Level (Outdoor): [Insert dB] dB(A)
• Operating Temperature Range (Heating): Down to [Insert Temp] °F

Controls and Operation

Primary control is via the wireless remote. Indoor unit may have limited manual buttons (ON/OFF, Operation Mode).

Remote Control Functions: POWER, MODE (Auto, Cool, Dry, Fan, Heat), TEMPERATURE ▲/▼, FAN SPEED (Auto, Low, Med, High), AIR SWING (Direction), TIMER (On/Off), FILTER RESET, "I FEEL"/FOLLOW ME, LOCK.

Operation Modes: AUTO: System automatically selects cooling or heating based on room temperature. COOL: Standard air conditioning. DRY: Dehumidification with mild cooling. FAN: Circulates air without cooling/heating. HEAT: Space heating.

Advanced Settings (via remote): Quiet mode, Powerful mode, Turbo function, Louver memory, Self-cleaning operation (on compatible models).

Connecting Indoor Units

The NAXSKS15A112A outdoor unit is compatible with various American Standard/Mitsubishi Electric indoor unit models (e.g., wall-mounted, ceiling cassette).

1. Select Compatible Indoor Unit: Refer to compatibility chart in technical guide.
2. Connect Refrigerant Lines: Use correct size piping (liquid and gas) as specified for the total system capacity and length.
3. Connect Communication Wiring: Use shielded 2-conductor communication cable between all indoor units and the outdoor unit in a daisy-chain configuration.
4. Address Setting (if multi-zone): Set the unique address on each indoor unit's PCB using dip switches or via remote procedure to allow individual control.
5. Power Supply: Indoor units typically receive control power from the outdoor unit via the communication lines. Verify per wiring diagram.

Tip: Always refer to the specific installation manual for the indoor unit model being installed.

Maintenance Procedures

Regular maintenance ensures efficiency, performance, and longevity.

1. Air Filter Cleaning: Turn system OFF. Remove filter from indoor unit. Vacuum or wash with lukewarm water and mild detergent. Dry completely before reinstalling. Perform every 2-4 weeks during operation.
2. Outdoor Unit Coil Cleaning: Turn OFF power. Gently brush or use low-pressure water to clean debris from fins. Ensure fins are not bent.
3. Indoor Unit Cleaning: Wipe casing with a soft, dry cloth. Do not use abrasive cleaners.
4. Condensate Drain Check: Periodically pour a small amount of water into the drain pan to ensure proper drainage.
5. Annual Professional Service: Schedule annual inspection by a qualified technician to check refrigerant charge, electrical connections, and overall system performance.

WARNING! Always disconnect power before performing any maintenance. Do not attempt to repair refrigerant circuit components.

Advanced Features & Settings

Self-Diagnosis: Indoor and outdoor units have LED indicators that flash error codes. Refer to service manual for code definitions (e.g., communication error, sensor fault, protection mode).

Auto-Restart: After a power failure, the system can automatically resume operation in the previous mode (if enabled).

Defrost Cycle (Heating Mode): In low ambient conditions, the outdoor unit will periodically enter a defrost cycle to melt ice from the coil. Fan may stop and a whooshing sound may be heard. This is normal.

Filter Reset Indicator: The "FILTER" light on the remote or indoor unit illuminates after a set runtime. Clean the filter and press the FILTER RESET button.

Care & Cleaning

Unplug or disconnect power before cleaning. Use only a soft, dry cloth for the indoor and outdoor unit cabinets. For stubborn stains, dampen cloth with mild soap solution, then wipe with a dry cloth.

CAUTION! Do not use water hotter than 110°F, volatile solvents, or abrasive cleaners. Do not splash water directly onto any part of the unit, especially electrical components.

Regulatory & Compliance Information

This equipment is designed to comply with Part 15 of the FCC Rules for Class B digital devices. It meets applicable UL and CSA safety standards. The refrigerant used (R-410A) is regulated by EPA Section 608; servicing must be performed by certified technicians. This product contains fluorinated greenhouse gases covered by the Kyoto Protocol. For warranty and support, contact American Standard Heating & Air Conditioning or visit www.americanstandardair.com.

Troubleshooting & Diagnostics

Reset: Turn system OFF at breaker for 5 minutes, then restore power to reset control board.

Service: For all refrigerant-related issues, error codes not resolved by reset, or electrical problems, contact an authorized American Standard/Mitsubishi Electric dealer or service technician. Do not attempt DIY repairs on sealed system.