nVent HOFFMAN T-Series Air Conditioner

General Safety Instructions

Observe the following general safety instructions for installation and operation of this product:

• This appliance is for installation only in locations not accessible to the general public.
• This appliance is not intended for use by persons, including children, with reduced physical, sensory, or mental capabilities, or lack of experience and knowledge, unless they have been given supervision or instruction concerning the use of the appliance by a person responsible for their safety.
• Children should be supervised to ensure that they do not play with the appliance.
• This appliance should be installed in accordance with national wiring regulations.
• Follow all precautions detailed in the following sections during transportation, receiving, testing, operation and maintenance.
• This appliance is intended for altitudes up to 10,000 ft (3,048 m) from sea level. For every additional 1000 ft of elevation, the capacity of this unit is derated by 1%.

Receiving the Air Conditioner

Inspect the air conditioner. Check for concealed damage that may have occurred during shipment. Look for dents, scratches, loose assemblies, evidence of oil, etc. Damage evident upon receipt should be noted on the freight bill. Damage should be brought to the attention of the delivering carrier -- NOT to nVent Equipment Protection -- within 15 days of delivery. Save the carton and packing material and request an inspection. Then file a claim with the delivering carrier.

nVent Equipment Protection cannot accept responsibility for freight damages; however, we will assist you in any way possible.

Handling and Testing the Air Conditioner

If the air conditioner has been in a horizontal position, be certain it is placed in an upright, vertical or mounting position for a minimum of five (5) minutes before operating.

CAUTION: Do not attempt to operate the air conditioner while it is horizontal or on its side, back or front. The refrigeration compressor is filled with lubricating oil. This will cause permanent damage to the air conditioner and also voids the warranty.

TEST FOR FUNCTIONALITY BEFORE MOUNTING THE AIR CONDITIONER TO THE ENCLOSURE.

Refer to the nameplate for proper electrical current requirements. If cord-connected, connect the power cord to a properly grounded power supply. If permanently connected, wire the unit to a properly grounded power supply using copper conductors only. Power supply wiring should be restrained to ensure no contact with the internal fan. Minimum circuit ampacity should be at least 125% of the amperage shown in the design data section for the appropriate model. No other equipment should be connected to this circuit to prevent overloading. The air conditioner is rated for operation at 50 and 60 Hz. No action is necessary to adjust the appliance operation at the rated frequencies.

Immediately after applying power, the evaporator blower (enclosure air) should start running. Operate the air conditioner for five (5) to ten (10) minutes. No excessive noise or vibration should be evident during this run period. The condenser blower (ambient air), the evaporator blower (enclosure air), and the compressor should be running.

Condenser air temperatures should be warmer than normal room temperatures within a few minutes.

The compressor is provided with automatic reset thermal overload protection. This thermo-switch is located and mounted inside the plastic enclosure clipped to the compressor. The switch operates when the compressor overheats due to clogged or dirty inlet air filter or if ambient air temperatures exceed nameplate rating or if enclosure dissipated heat loads exceed the rated capacity of the air conditioner. The thermal overload switch will actuate and stop compressor operation. The blowers will continue to operate and the compressor will restart after it has cooled to within the thermal overload cut-in temperature setting.

Installation Instructions

1. Inspect the air conditioner and verify correct functionality before mounting the air conditioner. See HANDLING AND TESTING THE AIR CONDITIONER on page 3.
2. Using the cutout dimensions shown in this manual, prepare the air "IN" and air "OUT" openings, and mounting bolt hole pattern for the enclosure. Select an installation location that will allow for adequate ventilation and clearance for service. Clearance between the air conditioner with or without a supplementary heater and adjacent structures (another enclosure, air conditioner, wall, or combustible surface) must be at least:
   • 24" from front
   • 2" from right side
   • 2" from left side
   • 6" from top
   • 8" from bottom
   Local fire codes may have different requirements; please observe applicable regulations for the location of the air conditioner. The distance between the air conditioner and the electronic components and other equipment installed inside the enclosure must be at least 3" to ensure adequate air circulation. At minimum clearance levels, an air baffle between the inlet and outlet may be necessary to prevent recirculation.
3. Using the gasket kit provided, install gaskets to air conditioner.
4. Mount air conditioner on enclosure using mounting bolts and screws provided. "EZ" mount tabs can be used to hold unit on enclosure while mounting in place. Allow unit to remain upright for a minimum of five (5) minutes before starting. Caution! Air conditioner must be in upright position during operation.
5. To avoid cross-threading mounting inserts, start bolts by hand before tightening with a wrench or ratchet driver.
6. When routing the drain tube, caution should be taken to keep it from kinking or being elevated above the exit point of the air conditioner. The drain tube must be on a continuous downward slope. A slight elevation of the tube could result in secondary trap. FAILURE TO FOLLOW THESE INSTRUCTIONS COULD RESULT IN OVERFLOWING OF THE CONDENSATE DRAIN PAN.
7. Refer to top of nameplate for electrical requirements. Connect the power cord or wire the unit to a properly grounded power supply by following applicable national wiring regulations. Use of an extension cord is not recommended. If the air conditioner is wired to the power supply, the electrical circuit should be fused with a time delay fuse or HACR circuit breaker per the MOPD rating in the Design Data table- see page 12.

Dimension Drawing

The dimension drawing provides a visual representation of the T15 Air Conditioner's physical layout and key measurements. It indicates:

• Overall dimensions: Height (approx. 15.75 inches), Width (approx. 7.50 inches), Depth (approx. 13.00 inches).
• Air inlet and outlet locations (labeled "AMB AIR IN", "AMB AIR OUT", "ENC AIR IN", "ENC AIR OUT").
• Mounting hole locations (1/4-20 MTG HOLES, 8 total).
• Drain stub location (3/8" DRAIN STUB).
• Front view showing the filter slot and mounting hardware access.
• Top view showing field changeable power cord location.
• Specific measurements for various features like fan diameter, mounting hole spacing, and component clearances.

Mounting Cutout Dimensions

This section details the required cutout dimensions for mounting the air conditioner into an enclosure. Two mounting configurations are shown:

• Externally Mounted: Provides dimensions for the opening in the enclosure wall, including height, width, and bolt hole positions. Phantom lines indicate the air conditioner's position relative to the cutout.
• Internally Mounted: Provides dimensions for the cutout when the unit is mounted from the inside of the enclosure.

Clearance notes indicate that the mounting gasket adheres to the air conditioner.

Wire Diagrams and Schematics

This section provides electrical diagrams for the T15 Air Conditioner, illustrating wiring and circuit configurations.

T15 without Heater Wire Diagram

This diagram shows the wiring connections for the T15 model without a heater. It includes connections for the compressor, condenser fan, evaporator fan, thermostat (T-STAT), run capacitor, compressor heater (if applicable, though this diagram is for 'without heater'), overload protection (O.L.), and the service cord. It also shows an optional malfunction switch.

T15 without Heater Schematic

This electrical schematic illustrates the circuit for the T15 unit without a heater. It shows the power supply (L1, L2), suppressor, evaporator fan, thermostat, condenser fan, freeze stat, run capacitor, and compressor with overload protection, connected in series and parallel as per their function.

T15 with Heater Wire Diagram

This diagram details the wiring for the T15 model equipped with a heater. It includes the components from the 'without heater' version plus the heater element and a heating thermostat (HEATING T'STAT) in addition to the cooling thermostat (COOLING T'STAT).

T15 with Heater Schematic

This electrical schematic shows the circuit for the T15 unit with a heater. It depicts the power supply (L1, L2), suppressor, evaporator fan, compressor heater, cooling thermostat, heating thermostat, condenser fan, freeze stat, run capacitor, and compressor with overload protection.

Component List and Parts List

These tables list the available components and their corresponding part numbers for different voltage configurations (115V and 230V).

Component List

Parts List

**Mounting gasket not shown

Technical Information

Design Data

The following table provides key design specifications for the T15 Air Conditioner models:

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

Temperature Control

The electromechanical thermostat is factory preset to 75°F/23°C. To adjust the temperature setting, remove the nylon plug from the front face of the unit and use a standard screwdriver. Turn clockwise for cooler temperatures and counterclockwise for warmer temperatures. The setpoint differential is 6°F.

Units With Heat

For units equipped with a heater, with a dial setting of 75°F:

• Heat turns on at 70°F and turns off at 75°F.
• Cooling turns on at 85°F and turns off at 80°F.

There is a 10°F difference between the heater off setpoint and cooling on setpoint to prevent simultaneous operation. The thermostat dial range is 50-95°F.

Principles of Operation

If electrical power is interrupted and reapplied within 3 to 5 seconds, the compressor may not restart immediately due to high back pressure. It requires approximately one (1) minute for suction and discharge pressures to equalize before the compressor can restart.

Operating the air conditioner below the minimum or above the maximum ambient temperatures indicated on the nameplate voids all warranties.

It is recommended to read the warranty section for parameters of restricted operation.

If moisture continuously flows from the drain tube, it indicates ambient air is entering the enclosure. Frequent opening of the enclosure door admits humid air, which the air conditioner must dehumidify.

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

Maintenance

Performing preventative maintenance (PM) at least twice a year, or more frequently in challenging environments (dusty, humid, high heat, oily, corrosive), helps maintain optimal efficiency and prevent product failures that may impact warranty coverage.

Compressor

The compressor requires no maintenance. It is hermetically sealed, factory-lubricated, and designed for long service life. Recharging ports are available for refrigerant service, which should only be performed by qualified refrigeration technicians. Never loosen or tamper with access fitting covers, as this will void the warranty.

Inlet Air Filter

Proper maintenance of the inlet air filter, located behind the front cover, is crucial for normal operation. Neglecting filter maintenance can decrease the maximum operating ambient temperatures. A dirty or clogged filter can cause the compressor to overheat and shut down via its thermal overload switch. The compressor will restart once cooled, but this cycle will repeat until the filter is cleaned. It is recommended to intentionally interrupt power when this occurs. A clogged filter reduces cooling airflow across the compressor and condenser coil.

Do not operate the unit for extended periods with the filter removed. Dust and lint can clog the condenser coil fins, mimicking a plugged filter. Protect the condenser coil with a filter.

Continued operation under these conditions can damage the compressor. The air conditioner features an easily removable inlet filter for convenient cleaning.

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

Research Products (RP) aluminum washable air filters are designed for high efficiency and dust holding capacity with minimal airflow resistance. They are lightweight and easy to service.

1. Cleaning Instructions:
2. Flush the filter with warm water from the exhaust side to the intake side. Do not use caustics.
3. After flushing, allow the filter to drain completely by placing it with a corner down.
4. Recoat the filters with RP Super Filter Coat adhesive, spraying from both sides for maximum concentration.

The inlet air filter is located behind the front cover. To access it, pull the ring protruding from the slot in the bottom of the front cover. The filter can then be cleaned or replaced.

Condenser and Evaporator Air Movers

Fan motors require no maintenance as bearings, shafts, etc., are lubricated during manufacturing for the life of the fan.

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

Refrigerant Loss

Each air conditioner is tested for leaks before factory shipment. Shipping damage or microscopic leaks may require repair or recharging by qualified professionals. Refer to the unit's nameplate for refrigerant type and charge size. Before recharging, ensure there are no leaks and the system is properly evacuated into a deep vacuum.

Preventative Maintenance/Inspection

This table outlines recommended maintenance and inspection tasks to be performed at least twice a year, or more frequently based on operational environment. It includes columns for recording the last completed date.

Trouble Shooting

This section provides flowcharts to diagnose and resolve common issues with the T-Series Air Conditioner.

Unit won't Cool (T-Series Compact with Manual Tstat)

Follow these steps:

1. Check for correct supply voltage. If incorrect, contact a certified electrician.
2. If voltage is correct, check if the evaporator fan is running.
• If not running, possible causes include a bad fan motor, bad wiring, bad capacitor, or a 230V transformer issue (if applicable).
3. If the evaporator fan is running, check if the enclosure temperature is 10°F above the setpoint.
• If it is, check if the compressor is running.
• If the compressor is not running, check if the condenser fan is running.
• If the condenser fan is not running, verify filter and condenser coils are clean. If they are clean, check for voltage at the condenser fan. If voltage is present, replace the condenser fan. If no voltage, troubleshoot the fan circuit.
• If the compressor is not running but the condenser fan is, consult the "Compressor won't start" flowchart.
4. If the enclosure temperature is not 10°F above setpoint, adjust the thermostat setting clockwise to call for cooling. If the temperature is below 80°F, the stop screw can be removed to adjust the thermostat lower for testing purposes. Check if the thermostat closes. If not, replace the thermostat.

Compressor won't start (Unit with Manual Tstat)

1. Check if the internal temperature is 10°F above the setpoint.
2. If yes, verify voltage at the compressor.
• If voltage is present, check for an open overload. If overload is open, replace it.
• If no voltage is present, check the thermostat closing and adjust as needed (see previous section).
3. If voltage is present at the compressor and overload is not open, check the capacitor(s) for proper capacitance and if the freeze stat is closed. If issues are found, replace the capacitor(s).
4. If the capacitor is good and the freeze stat is closed, but the compressor still won't start, possible causes include loose wiring or connections, a bad door switch, bad transformer, or a bad door switch relay.
5. If the compressor is shorted to ground, replace the compressor.

Evaporator Coils Freezing (Unit with Manual Tstat)

1. Check if the evaporator and condenser fan(s) are running.
• If not running, check for voltage to the inoperable fan. If voltage is present, check if the capacitor measures correct capacitance. If the capacitor is faulty, replace it. If the capacitor is good, possible causes include faulty electrical connections for one or both fans, a bad HPC (if equipped), or insufficient pressure.
2. If fans are running, check if the unit has airflow.
• If no airflow, clean/replace the filter and clean the condenser coil.
3. If airflow is present, check if the enclosure is properly sealed (no outside air leaking in).
• If not sealed, replace seals and gaskets on the enclosure and monitor for normal operation.
• If sealed, verify the compressor can satisfy the cooling setpoint.
• If it cannot, verify the cooling setpoint is at the recommended level. If it is, contact technical support.
• If the unit is icing up, possible causes include low refrigerant or a leak.

Unit Tripping Breaker (Controller or Manual Tstat)

1. Check if the breaker trips instantaneously.
• If yes, check power connections and components for a possible short circuit and verify the correct power supply.
• If no, check if the breaker trips when the compressor comes on.
• If yes, check if the compressor is shorted to ground. If it is, replace the compressor.
• If the compressor is not shorted to ground, check if the fuse and breaker are the correct type and sized accordingly. If not, replace them with the correct type and size.
• If the fuse and breaker are correct, check electrical connections and component amp draw.

Water in the enclosure

Follow these steps to diagnose water issues:

1. Is the condensate drain plugged/restricted?
• If yes, unplug/remove the restriction.
• If no, proceed to the next step.
2. Is the cabinet properly sealed (door gaskets, conduit openings, mounting gaskets, etc.)?
• If not properly sealed, properly seal the cabinet.
• If sealed, check if the unit is icing up.
• If icing up, refer to the "Evaporator coils freezing up" flowchart.
• If not icing up, contact Tech Support at 763-422-2211 ext 1-2-3.

F-Gas Information

This section provides information related to refrigerants and their environmental impact, including data in English, German, and Polish.

Additional Technical Support

For further assistance:

• Call: 763-422-2211
• Email: cooling.service@nVent.com
• Download Field Service Request (FSR) from: http://HOFFMAN.nVent.com/en-us/cooling-field-service-request

Company Information

nVent

2100 Hoffman Way

Anoka, MN 55303 USA

Tel: +1.763.422.2211

Fax: +1.763.576.3200

Our powerful portfolio of brands: CADDY, ERICO, HOFFMAN, ILSCO, RAYCHEM, SCHROFF

©2024 nVent. All nVent marks and logos are owned or licensed by nVent Services GmbH or its affiliates. All other trademarks are the property of their respective owners. nVent reserves the right to change specifications without notice.

Document Part Number: HOFFMAN-IM-N02436-T15InstallationManual-USEN-2409

Product Part Number: 10-1008-194

Serial Number Reference: 89059119

nVent.com/HOFFMAN