nVent HOFFMAN NXT-NOX Cooling Units

1. General Information

WARNING: Read the following instructions carefully before installing and using the product.

1.1 Overview

The product is manufactured by TEXA INDUSTRIES S.r.l. in compliance with applicable EC directives, including the Machinery Directive 2006/42/EC and relevant harmonised and safety regulations.

1.2 Purpose of the Manual

This manual provides all information necessary for the safe installation, use, and maintenance of the product.

1.3 Symbols Contained in this Manual

• WARNING: Indicates potential for serious or fatal personal injury if instructions are not followed.
• CAUTION: Indicates potential for minor injury or product damage if instructions are not followed.
• Notice: Provides important information for using the machine.

1.4 Retention of Documents

This manual is an integral part of the product. Ensure it is available to all users and maintenance personnel. Store it in a clean, dry location.

1.5 Updates

TEXA INDUSTRIES S.r.l. reserves the right to update products and manuals without prior notice. Manuals reflect the product state at the time of sale.

1.6 Technical Features

Technical features and CE marking are detailed on the machine's data plate. The product includes a safety instruction manual, test report, and CE declaration of conformity.

1.7 Cooling Unit Application

The NXT/NOX series cooling units are designed to cool air inside electrical switchboards, protecting components from thermal shock. They offer IP55 protection against contaminants and aggressive substances.

1.7.1 Intended Use

Use the NXT/NOX cooling unit for cooling electrical switchboards within specified temperature and voltage limits, away from heat sources, in environments with adequate air exchange, and on switchboards with at least IP54 rating. Ensure cable entry points are sealed to prevent condensation. The compressor must always remain upright.

1.7.2 Misuse

WARNING: Incorrect use can cause irreparable damage and hazardous situations. Do not use the unit:

• Outside of specified conditions.
• In explosion-risk atmospheres or environments with high concentrations of dust, chemicals, or oil.
• Exposed to elements, strong radiated heat, or magnetic fields.
• With switchboard doors open or on enclosures below IP54 rating, as this can cause excessive condensation.
• With the temperature set below the dew point of ambient air.
• With a blocked condensate line or where condensate cannot drain freely.
• Without the front panel.
• With obstructed air intake/outlet flows. Ensure minimum distances (see figure F.02) and no internal obstructions.
• On moving, oscillating, or vibrating parts.

Notice: Product warranty is void if used under incorrect conditions or tampered with. TEXA INDUSTRIES S.r.l. is not liable for faults due to non-compliance. Regular scheduled maintenance (Section 9) is required for correct operation.

2. Technical Information

2.1 Operating Principles

The cooling unit operates on a refrigeration circuit with a compressor, evaporator, condenser, and expansion device. It uses R134a/R513A refrigerant. The unit has two separated sections for ambient and enclosure air. The cycle involves refrigerant compression, condensation, expansion, and evaporation to cool the enclosure air.

2.2 Safety Devices

WARNING: Do not disable safety devices, as this invalidates the warranty and creates a hazard. The unit includes a high-pressure safety switch and thermal cut-outs for fans and the compressor.

3. Supply

The packaging includes:

• 1 Cooling unit
• 1 Safety instruction manual
• 1 CE conformity certificate
• 1 Test certificate
• 1 A4 drilling template
• 1 Installation kit (flanged nuts, flat washers, grub screws, connectors for power and signals, self-adhesive sealing strip, hose barb for condensate discharge)
• Transport/handling eyebolts (for NXT12-NXT60 and NOX12-NOX60 models)

4. Transport and Handling

WARNING: Operations must be performed by qualified personnel with appropriate PPE. Do not exceed manual handling weight limits. Use lifting equipment as needed.

CAUTION: Dispose of packaging materials environmentally. Check for transport damage upon receipt. Ensure the product has no dents or leaks.

Keep the unit vertical during transport and storage, avoiding temperatures above 70°C or below -20°C. Use supplied eyebolts for lifting.

Notice: Contact TEXA INDUSTRIES S.r.l. in writing for any damage or discrepancies.

5. Installation

WARNING: Disconnect power before working inside the switchboard. Installation must be by authorised personnel with appropriate PPE.

CAUTION: Deburr holes to prevent cuts.

Install the unit with the air intake hole at the highest possible point. Ensure fixing elements do not interfere with internal equipment. If wall-mounting, ensure the door can support the weight. The unit must be installed vertically, with a maximum deviation of 2°.

5.1 Installation of External Installation Versions

Mount the unit externally. Use the provided drilling template to cut holes in the enclosure. Fit the sealing strip and follow the assembly diagram.

5.2 Installation of Semi-Recessed Installation Versions

The unit can be installed externally or semi-recessed. Drill holes using the template and fit the sealing strip. Follow the specific installation diagram.

6. Condensate Runoff Pipe

Condensate formation is normal. Models NXT04-NXT06-NXT08 and NOX06-08 drain condensate via a hose. A hose barb is supplied for connecting an 8mm ID hose. Ensure the condensate flows freely, avoiding horizontal runs over 0.5m, uphill sections, and traps. The pipe end must be free and not submerged. Models NXT10-NXT60 and NOX10-NOX60 have an integrated evaporation device, but also an emergency outlet. Using the unit with enclosure doors open can cause excessive condensation; a door position switch is recommended.

7. Electrical Connection

WARNING: Electrical connections must be made by specialised personnel according to electrical codes. Isolate power before connection. Ensure the machine is correctly earthed.

CAUTION: Verify supply voltage compatibility. Protect the power supply with appropriate fuses or circuit breakers.

7.1 Two-Phase Models

Models operate on 460 V 2~50-60 Hz or 400 V 2~50-60 Hz. Connect terminals L1(0) and L3(460) for 460V, or L1(0) and L2(400) for 400V. UL-listed models have fuses.

7.2 Three-Phase Models

Models with 400 V 3~ 50 Hz can also operate on 460 V 3~ 60 Hz by modifying cable connections. UL-listed models have fuses.

7.3 Alarm Pins

Alarm signals are managed via alarm pins. Alarm signals are available on terminals 1-2-3. A digital input for voltage-free contacts is on terminals 4-5. If the digital input is not used, bridge terminals 4 and 5.

7.4 Sequencing (optional)

Two cooling units can be connected in sequence via a 4-pole connector. The cable is not supplied. Refer to the control unit manual for parameter settings.

7.5 Modbus (optional)

Modbus connection is possible via a 4-pole connector. The cable is not supplied. Refer to the control unit manual for parameter settings.

8. First Start-up and Regulation

CAUTION: If the unit was left in an incorrect position, wait at least 8 hours before switching on. Otherwise, 30 minutes is sufficient for oil return.

Upon power application, the enclosure air intake fan operates intermittently. If the internal temperature exceeds the set point by 2K, the compressor and external fan activate. The cycle stops when the set point is reached. The factory set point is 35°C, adjustable between 20°C and 45°C. For energy saving and reduced condensate, a set point below 30°C is not recommended.

8.1 Electronic Thermostat

NXT04 models use a TX050 electronic thermostat. Refer to manual C17000199 for programming.

8.2 Electronic Board

Other NXT models have an electronic board and display for parameter modification. Refer to manual C17000905.

8.3 Remote Display

NOX models include an electronic board and a remote display with a 3-meter cable and DIN bar mounting kit. Refer to manual C17000905.

Notice: TEXA INDUSTRIES S.r.l. is not liable for alterations to default parameters made without authorization.

9. Maintenance

WARNING: Shut off power before any operation. Maintenance must be performed by authorised personnel with appropriate PPE. Allow components to cool to ambient temperature.

CAUTION: Do not use acidic or flammable detergents.

The cooling unit requires minimal maintenance, with no filter changes needed. Regular checks of internal components are recommended:

Notice: Increase frequency in dusty/dirty environments.

10. Removal and Dismantling

WARNING: Shut off power before operation. Removal and dismantling must be by authorised personnel with appropriate PPE.

The cooling unit contains refrigerant (R134a/R513A) and lubricating oil, which are polluting substances and must not be dumped. Recover refrigerant for reuse, regeneration, or destruction by certified personnel.

11. Troubleshooting

12. Pictograms

Diagrams illustrating installation, handling, and connection principles are provided in the original document (Figures F.01 through F.20).

• F.01: Orientation and handling symbols.
• F.02: Minimum clearance requirements for external air flow.
• F.03: Unit with handling eyebolts.
• F.04: External mounting diagram.
• F.05: Semi-recessed mounting diagram.
• F.06: Semi-recessed mounting diagram.
• F.07: Condensate pipe routing restrictions (avoid horizontal runs, uphill sections, traps).
• F.08: Condensate pipe end must not be placed in a collection container.
• F.09: Warning against using the unit with enclosure doors open.
• F.10: Hose barb for condensate discharge.
• F.11: Cleaning with compressed air (max 4 bar).
• F.12: Refrigeration circuit diagram (CP: Compressor, C: Condenser, EXP: Expansion Device, E: Evaporator, Vc: Condenser Fan, Ve: Evaporator Fan).
• F.13: Condensate evaporation device location.
• F.14: Electrical connection diagrams for different voltage/phase models.
• F.15: Alarm pin connections (digital output, digital input).
• F.16: Fuse locations on UL-listed models.
• F.17: Sequencing connection (4-pole connector).
• F.18: Modbus connection (4-pole connector).
• F.19: Three-phase voltage connection modification.
• F.20: Remote display connection.

13. Technical Data (F.21)

The document provides extensive technical data tables detailing specifications for various NXT and NOX models. Key parameters include:

• Model Number
• Useful Cooling Output (W)
• Supply Voltage (V ~ Hz)
• Dimensions (W x H x D)
• Max Current (A), Starting Current (A), Pre-fuse T (A)
• Electric Capacity (W), Duty Cycle (%)
• Max Pressure Range (bar)
• Enclosure Temperature Range (°C)
• Ambient Temperature Range (°C)
• Protection (IP Type)
• Noise Level (dB(A))
• Weight (kg)
• Temperature Control Type
• Conformity (e.g., CE, UKCA, UL)

These tables cover models from NXT04 up to NXT60 and corresponding NOX series, detailing variations in cooling capacity, electrical requirements, and physical dimensions.

14. Performances (F.22)

Performance graphs illustrate the cooling output (P) in Watts against ambient temperature (Ta) in °C, for various internal enclosure temperatures (Ti) in °C. Graphs are provided for model series NXT04, NXT06/NOX06, NXT08/NOX08, NXT10/NOX10, NXT12/NOX12, NXT16/NOX16, NXT20/NOX20, NXT30/NOX30, NXT40/NOX40, and NXT60/NOX60.

15. Dimensions (F.23)

Dimensional drawings show the external mounting and semi-recessed mounting configurations for various NXT and NOX models, including specific measurements for width, height, and depth, as well as clearance requirements.

16. Spare Parts (F.24)

Exploded view diagrams identify key components for various model series (NXT04, NXT06-08/NOX06-08, NXT10/NOX10, NXT12-16-20/NOX12-16-20, NXT30-40/NOX30-40, NXT60/NOX60). Components include:

• Front structure
• Condenser
• Evaporator
• Compressor
• Condenser fan
• Evaporator fan
• Electric Control
• Display
• Electronic Board
• Autotransformer
• Assembly accessory kit

When ordering parts, provide the Model, Serial number, Date of production, and requested part code.

17. Guarantee

TEXA INDUSTRIES S.r.l. guarantees products against quality defects for 12 months from shipment, provided they are used under specified conditions:

• Within temperature limits indicated on the rating plate.
• For cooling capacities not exceeding those indicated on the rating plate.
• In premises with temperatures within the specified range.
• On panels/enclosures with at least IP54 protection.
• In compliance with the operating and maintenance manual.

The guarantee does not cover damage from:

• Incorrect refrigerant type or quantity.
• Use in unsuitable premises (acidic or corrosive atmosphere).

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. Maintenance requested at the customer's premises will be billed. The warranty is invalidated by tampering.

To claim under the guarantee, provide the purchase document and serial number.

18. Assistance Service

For malfunctions, technical information, or installation advice, contact TEXA INDUSTRIES S.r.l. Assistance Service:

Strada Cà Bruciata, 5
46020 - Pegognaga (MN) – ITALIA
Tel: +39 0376 554511
e-mail: texa.service@nVent.com

Ensure you have the full machine code number and serial number before contacting them. All requests must be in writing (email or fax).

Warning: Equipment returns require manufacturer request and agreement.

19. Notes

Blank section for notes.