nVent T-Series Air Conditioner

Warranty and Return Policy

For warranty and return information, visit: https://hoffman.nvent.com/en/hoffman/warranty-information

Important Notice

These instructions were authored in English. Instructions published in languages other than English have been translated from the authored language.

These air conditioners are intended for use by properly trained customers in industrial, communications, and agricultural environments.

Operating sound level is below 70 dBA.

⚠ WARNING Disconnect the power source from the air conditioner before servicing.

Receiving the Air Conditioner

Inspect the air conditioner for concealed damage such as dents, scratches, or loose assemblies. Note any damage on the freight bill. Report damage to the delivering carrier within 15 days of delivery. Save the carton and packing material for inspection. nVent Equipment Protection cannot accept responsibility for freight damages but will assist in the process.

Handling and Testing the Air Conditioner

If the air conditioner has been in a horizontal position, ensure it is placed upright for a minimum of five (5) minutes before operating.

CAUTION Do not operate the air conditioner horizontally or on its side, back, or front, as this can cause permanent damage to the refrigeration compressor and void the warranty.

Before mounting, test the air conditioner's functionality. Connect the power cord to a properly grounded power supply. Ensure the circuit ampacity is at least 125% of the amperage shown on the nameplate. Operate the unit for five to ten minutes, checking for excessive noise or vibration. The condenser blower, evaporator blower, and compressor should be running. Condenser air temperatures should rise within minutes.

The compressor has automatic reset thermal overload protection. This switch will stop the compressor if it overheats due to a dirty filter, high ambient temperatures, or excessive enclosure heat loads. The blowers will continue to operate, and the compressor will restart once it cools down.

Installation Instructions

1. Inspect the air conditioner and verify functionality.
2. Determine surface or recess mounting and prepare the enclosure opening using the cutout dimensions provided.
3. Install gaskets to the air conditioner.
4. Mount the air conditioner using 1/4-20x.625 mounting bolts. Ensure the unit remains upright for at least five (5) minutes before starting.
5. Start bolts by hand to avoid cross-threading.
6. Route the drain tube with a continuous downward slope to prevent condensate pan overflow.
7. Connect the power cord to a properly grounded power supply. Use a slow blow or HACR circuit breaker. Extension cords are not recommended.

Design Data

-XXX will be replaced with a three-digit number designating all desired options. Consult the factory for specific model numbers.

Dimensional Drawing

The dimensional drawing shows the overall dimensions of the unit, including mounting hole locations, air intake and outlet positions, drain stub, and power cord entrance. It provides measurements for both externally and internally mounted configurations.

Mounting Cutout Dimensions

Detailed cutout dimensions are provided for both externally and internally mounted configurations, indicating precise measurements for enclosure openings.

Components List

Wire Diagrams

Wiring diagrams are provided for units Without Heat and With Heat, illustrating the electrical connections for various components including the compressor, fans, thermostat, and optional switches.

Schematic

The electrical schematic provides a simplified representation of the air conditioner's electrical system, showing the flow of power through components like the enclosure fan, compressor heater, heating thermostat, cooling thermostat, condenser impeller, and compressor.

Temperature Control

The electromechanical thermostat is factory preset to 75°F/23°C. To adjust, remove the nylon plug and use a screwdriver. Clockwise rotation lowers the temperature; counterclockwise rotation raises it. The setpoint differential is 6°F.

Units With Heat

Air conditioners with electric heat have two thermostats, one for cooling and one for heating. Thermostats are factory set for cooling at 80°F/27°C and heating at 55°F/13°C, with a 10°F differential. Setpoints below 100°F have a variance of ±3°F, and at 100°F, the variance is ±4°F.

Example

For cooling set at 80°F, the unit turns on at 90°F (±3°F) and off at 80°F (±3°F). For heating set at 55°F, the unit turns on at 55°F (±3°F) and off at 65°F (±3°F).

To Change the Temperature Setting

Remove the nylon plug covering the adjustment screw. Use a screwdriver to turn the screw clockwise for cooler settings and counterclockwise for warmer settings. Reinstall the nylon plugs.

Dial Ranges

Cooling thermostat dial range: 70°F to 100°F. Heating thermostat dial range: 55°F to 65°F.

Thermostat stop screws limit these ranges. Removing them for purposes other than testing may affect performance (e.g., coil icing, frequent cycling).

Testing Thermostat Calibration

Cooling Thermostat: Set the cooling thermostat to its lowest position. Measure intake air temperature. Turn the thermostat dial counterclockwise at 1°F per second until the compressor stops. Note the reading. The difference between the measured temperature and the dial reading should be within ±3°F.

Heating Thermostat: Set the heating thermostat to its lowest position. Measure intake air temperature. Turn the heating thermostat dial counterclockwise at 1°F per second until the heater starts (indicated by a change in unit amps). Note the reading. The difference between the measured temperature and the dial reading should be within ±3°F.

Principles of Operation

If power is interrupted and reapplied within 3-5 seconds, the compressor may not restart immediately due to high back pressure. Allow one minute after shutdown for pressures to equalize.

Operating the unit outside the specified minimum or maximum ambient temperatures voids the warranty.

Moisture in the enclosure air is limited. Continuous moisture from the drain tube indicates ambient air entry. Frequent opening of the enclosure door admits humid air that the air conditioner must dehumidify.

Units with the optional malfunction switch have specific wiring connections: red & yellow wires are normally open, red & blue wires are normally closed. During an alarm, red & yellow close, and red & blue open. Maximum electrical ratings for the switch are 13A for 120 VAC and 10A for 240 VAC.

Maintenance

Compressor

The compressor requires no maintenance as it is hermetically sealed and factory lubricated. Recharging ports are available for refrigerant service, but access fitting covers should not be loosened or removed, as this voids the warranty.

Inlet Air Filter

Regular maintenance of the inlet air filter ensures normal operation. A dirty or clogged filter can cause the compressor to overheat and shut down via the thermal overload switch. The compressor will restart once cooled. This condition can be caused by a dirty filter or clogged condenser coil, reducing cooling airflow.

Do not operate the unit for extended periods without the filter. Dust and lint can clog the condenser coil fins. The unit is available with an easily removable filter for cleaning.

How to Remove, Clean or Install a New Inlet Air Filter

RP aluminum washable air filters provide efficient filtering. Recoat filters with RP Super Filter Coat adhesive after washing for optimal performance. Clean filters regularly.

Accessing the filter: Pull the ring protruding from the slot in the bottom of the front cover.

Cleaning Instructions:

1. Flush with warm water from the exhaust side to the intake side. Do not use caustics.
2. Allow the filter to drain completely.
3. Recoat with RP Super Filter Coat adhesive, spraying from both sides for maximum concentration.

Condenser and Evaporator Air Movers

Fan and impeller motors require no maintenance as bearings and shafts are lubricated for life during manufacturing.

CAUTION Operation in areas with airborne caustics or chemicals can damage filters, coils, blowers, and motors. Contact nVent Equipment Protection for special recommendations.

Refrigerant Loss

Air conditioners are tested for leaks before shipping. If leaks occur due to shipping damage or microscopic issues, professional repair or recharging may be necessary. Refer to the nameplate for refrigerant type and charge size. Ensure the system is leak-free and properly evacuated before recharging.

Trouble Shooting

Basic Air Conditioning Trouble Shooting Check List

1. Check Power Supply: Verify the manufacturer's nameplate for correct power supply.
2. Evaporator Fan: Turn on power. The evaporator fan should run. If not, check for open motor winding, stuck fan motor, or obstructed blades.
3. Condenser Fan & Compressor: Adjust thermostat to the lowest setting. The condenser fan and compressor should turn on. If not, the thermostat may be defective.
4. Both Fans & Compressor Running: If not, the unit will not cool properly.
5. Condenser Fan Airflow: Check for airflow from the condenser fan. If not, check for a defective thermostat, open motor winding, stuck impeller motor, or obstructed wheel.
6. Compressor Operation: Check for slight vibration and a warm outer case. If not, check for a defective thermostat, capacitor, overload, or relay.
7. Coil Cleanliness & Temperatures: Ensure coils are clean. Check evaporator 'air in' and 'air out' temperatures. If they are the same, suspect refrigerant loss or bad compressor valves.
8. Thermostat Test: Turn off power. Remove control box cover. Connect both thermostat wires to one terminal. Turn power on. If both fans and compressor operate, the thermostat needs replacement.

Symptoms and Possible Causes

For additional technical information, contact nVent Equipment Protection at 800-896-2665.

F-Gas Information