Nordyne NS6QD SERIES - User Manual

This document is a user's manual and installation instructions for the NS6QD Series outdoor split system air conditioner, designed for manufactured housing. It provides comprehensive information for both users and installers to ensure safe, efficient, and long-lasting operation of the unit.

Function Description

The NS6QD Series air conditioner is designed to provide cooling and, with optional equipment, heating for manufactured homes. It operates as an outdoor split system, meaning it works in conjunction with an indoor unit (air handler or furnace) to circulate conditioned air throughout the living space. The system utilizes R-410A refrigerant and is designed for ground-level or rooftop installations. Its primary function is to maintain a desired indoor temperature, offering both cooling and, when paired with appropriate indoor heating equipment, heating capabilities. The unit is designed for automatic operation, where it cycles on and off as needed to maintain the set temperature.

Usage Features

The air conditioner's operation is controlled via a thermostat, which allows users to select system modes (COOL, HEAT, AUTO, OFF) and fan modes (AUTO, ON), as well as set the desired temperature.

Cooling Operation: To cool, the thermostat's system mode should be set to COOL or AUTO, and the fan mode to AUTO. The temperature selector is then set to the desired cooling level. The outdoor fan, compressor, and indoor blower motor will cycle automatically to maintain this temperature. A protective timer circuit prevents immediate restarts of the compressor and outdoor fan for approximately 5 minutes after a system reset or power interruption, safeguarding the equipment.
Heating Operation (Optional): If the system includes optional heating equipment (furnace or electric heat), the thermostat's system mode is set to HEAT or AUTO, and the fan mode to AUTO. The temperature selector is then set to the desired heating level. The heating equipment will cycle on and off to maintain the indoor temperature.
Automatic Cooling & Heating: When the thermostat system mode is set to AUTO, the unit will automatically switch between cooling and heating operations to maintain the desired temperature, eliminating the need for manual mode changes.
Continuous Indoor Blower Operation: The fan mode can be set to ON to run the indoor blower continuously. This feature is useful for circulating indoor air to equalize temperature imbalances caused by factors like sun load, cooking, or a fireplace, regardless of whether the system is actively cooling or heating.
Turning the Air Conditioner OFF: To turn off the system, the thermostat's system mode should be set to OFF, and the fan mode to AUTO. This ensures the system will not operate, irrespective of the temperature setting.

Maintenance Features

Proper and frequent maintenance is crucial for optimal performance and longevity of the NS6QD Series air conditioner. The manual outlines several key maintenance tasks, emphasizing that these should ideally be performed by qualified, trained personnel due to the presence of pressurized refrigerants and electrical components.

Outdoor Unit Cleanliness: The outdoor unit should be kept clean by periodically hosing it off and ensuring its fins are free of leaves and grass clippings. Obstructions like tall plants or shrubs should not block airflow, and flammable materials like gasoline should not be stored near the unit.
Air Filter Inspection and Replacement: Air filters in the return air duct must be inspected frequently and replaced as necessary, ideally at the beginning of each heating and cooling season. The unit should never be operated without a filter.
Condensate Drain and Outdoor Coil Inspection: At the start of each cooling season, the condensate drain and outdoor coil should be inspected, and any debris removed. The outdoor coil and louvers can be cleaned with a mild detergent and water, followed by a thorough rinse.
Electrical Connection Inspection: Electrical connections should be inspected for tightness at the beginning of each heating and cooling season to ensure safe operation.
Troubleshooting: The manual provides basic troubleshooting steps for common issues, including checking thermostat settings, circuit breakers, air filters, and the cleanliness of the outdoor unit.
Refrigerant Charging: This is a critical maintenance procedure that must be performed by qualified personnel. The unit leaves the factory with a holding charge of R-410A refrigerant. Charging instructions, including the use of charging charts (Figures 8-13), are provided to ensure maximum unit performance and efficiency. The process involves measuring liquid refrigerant pressure and temperature at the service valve and adjusting the charge based on the appropriate chart. The manual explicitly warns against adding or removing refrigerant if the pressure reading falls between the specified curves.
High Pressure Switch (HPS): The unit includes a factory-installed high-pressure switch to protect the system from excessively high pressures. This switch automatically de-energizes the outdoor unit if liquid pressure exceeds 575 psig and re-energizes it once pressure drops to 460 psig, with a potential 5-minute short cycling delay.

The manual also stresses the importance of adhering to all local codes and regulations for installation and servicing, and warns against unqualified individuals attempting to install or service the equipment to prevent personal injury, property damage, or death. It also provides a list of replacement parts available through distributors, including electrical components (capacitors, compressors, contactors, relays, switches, transformers), motors (blower and fan), and other components (blower assembly, cabinet panels, expansion valves, fan grille, filter/driers).