The TEXA NXT series cooling units are designed for cooling electrical switchboards to protect components sensitive to thermal shock and provide IP55 protection against contaminating and aggressive/corrosive substances. These units are suitable for door or wall mounting.

Function Description:

The NXT cooling unit operates on a refrigeration circuit, which is sealed and contains R134a refrigerant, a chlorine-free and ozone-friendly substance. The unit is divided into two hermetically separated sections, treating ambient air and enclosure air separately without contact. The compressor (CP) compresses the refrigerant to a high pressure and temperature. This refrigerant then passes through the condenser (C), where it is cooled by ambient air, transitioning from gas to liquid. Next, it flows through an expansion valve (EXP), vaporizing at a lower pressure and temperature. Finally, it enters the evaporator (E), absorbing heat from the enclosure air and changing from liquid to gas, thereby cooling the enclosure. The gaseous refrigerant is then drawn back into the compressor, repeating the cycle.

Important Technical Specifications:

The technical features and CE marking are provided on the unit's data plate. The product is supplied with a safety instruction manual, wiring diagram, specific test report, and CE declaration of conformity.

Refrigerant: R134a (chlorine-free, ozone-friendly).
Protection Level: IP55 (against contaminating and aggressive/corrosive substances).
Supply Voltages:
- Two-phase models: 460V 2~50-60Hz and 400V 2~50-60Hz.
- Three-phase models: 460V 3~60Hz and 400V 3~50Hz.
Thermostat Setpoint Range: 20°C to 45°C (factory-set to 35°C).
Condensate Evaporation: Models NXT10 to NXT60 feature a condensate evaporation device using the compressor's hot discharge tube. All models also include an emergency condensate outlet.
Safety Devices: The refrigeration circuit is equipped with an EN 12263 compliant high-pressure safety switch (P) set to the maximum working pressure. This switch cuts out the compressor if the threshold is exceeded and restores it automatically. Fans and the compressor also have thermal cut-out switches to prevent overheating.
Electrical Protection: The power supply must be protected upstream by appropriate time-delay fuses (type T) or circuit breakers with K-curve, as indicated in table F.13.

Usage Features:

Intended Use: Cooling electrical switchboards within specified temperature and supply voltage limits (as per rating plate F.04, pos. 5, and table F.13), away from heat sources or hot air, in environments with adequate air exchange. The switchboard must have an IP54 or higher rating, with cable entry points and other openings well sealed to prevent excessive condensation. The compressor must always remain upright.
Misuse (Prohibited): Do not use in explosion-risk atmospheres, with aggressive chemicals, excessive dust, solid contaminants, or oil suspended in the air. Avoid exposure to elements, strong radiated heat, or strong magnetic fields. Do not operate with open electrical switchboard doors or on enclosures below IP54, as this leads to excessive condensate. Do not set the temperature below the ambient air's dew point. Ensure the condensate line is clear and unobstructed. Do not operate without the front panel or with obstructed airflows (check minimum distances in figure F.02 for external airflow and ensure no internal obstructions). Do not install on moving, oscillating, or vibrating parts.
Installation: The unit must be installed vertically (maximum permitted deviation of 2°), with the enclosure air intake hole at the highest possible point. Ensure fixing elements do not interfere with internal equipment. For door mounting, verify the door can support the unit's weight.
- External Installation: Mount the unit on the outside of the electrical switchboard using the provided drilling template (figure F.04). Apply the sealing strip on the side connected to the enclosure.
- Semi-Recessed Installation: Depending on requirements, the unit can be installed externally (figure F.05) or semi-recessed (figure F.06) without additional accessories. Use the drilling template and sealing strip as for external installation.
Condensate Runoff: For NXT04-NXT06-NXT08 models, condensate is discharged via a hose at the bottom. A supplied hose barb (figure F.10) allows an 8mm ID hose to be attached for external drainage. Ensure the condensate flows freely, avoiding horizontal lengths over 0.5 meters, uphill sections, and accidental traps (figure F.07). The pipe end must always be free and never submerged (figure F.08). For NXT10-NXT60 models with condensate evaporation, an emergency outlet is still available.
Electrical Connection: All electrical work must be performed by qualified and authorized personnel, adhering to electrical codes. Isolate power during connection and ensure proper earthing. Verify supply voltage compatibility with the unit's rating plate.
Alarm Pins (figure F.15): Input/output signals are managed via alarm pins. Positions 1-2-3 provide alarm output signals (relay changes state on alarm). Terminals 4-5 provide a digital input for voltage-free contacts; if unused, these terminals must be bridged.
Sequencing (optional, figure F.17): Two units can be connected in sequence via a red 4-pole connector (cable not supplied). Refer to the control unit manual for parameter settings.
Modbus (optional, figure F.18): A Modbus connection can be made via a 4-pole connector (cable not supplied). Refer to the control unit manual for parameter settings.
First Start-Up: If the unit was stored incorrectly (figure F.01), wait at least 8 hours before powering on (30 minutes if stored correctly). The enclosure air intake fan will operate intermittently to equalize internal temperature. If the temperature exceeds the setpoint by 2K, the compressor and external air fan will activate for cooling. Cooling stops when the internal temperature reaches the setpoint.
Electronic Thermostat/Board: NXT04 models use a TX050 electronic thermostat (manual C17000199). Other NXT models use an electronic board with a display for parameter modification (manual C17000905).

Maintenance Features:

The cooling unit is designed for low maintenance, requiring no filter changes.

Regular Maintenance (see table in section 9):
- Every 3 months: Check and clean the external air heat exchanger if necessary. Check the effectiveness of the condensate discharge.
- Every 6 months: Check fans for overheating or excessive vibrations.
Increased Frequency: In very dusty or dirty environments, increase the frequency of these operations.
Cleaning: Clean internal components with compressed air at a maximum pressure of 4 bar (figure F.11). Do not use acidic or flammable detergents.
Safety Precautions: Always shut off power before any maintenance. Maintenance must be performed by authorized and qualified personnel using appropriate PPE. Allow internal components to reach ambient temperature before working.
Disassembly and Disposal: Disassembly and disposal must be performed by authorized and qualified personnel using appropriate PPE. The unit contains R134a refrigerant and lubricating oil, which are pollutants and must not be released into the environment. Certified personnel must recover the refrigerant according to Regulation (EU) 517/2014 for recycling, regeneration, or destruction.

Warranty:

TEXA INDUSTRIES S.r.l. guarantees the product against quality defects and all components for 12 months from the shipment date, provided it is used under specific conditions (temperatures within rating plate limits, appropriate cooling capacities, IP54+ enclosures, and adherence to the "operating and maintenance" manual). The warranty does not cover damage from using incorrect refrigerant types/quantities or operation in unsuitable (acidic/corrosive) atmospheres. Faulty components will be repaired or replaced free of charge at the manufacturer's discretion. Additional expenses for removal, handling, or installation are not covered. On-site maintenance, even during warranty, will be billed. The warranty is automatically invalidated by any tampering with the product. To claim warranty, the purchase document and the product's serial number (found on the rating plate) are essential.

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