Dehydration/Leak Test

Air-Cooled Models

1.Make sure unit is OFF. Open all disconnect switches and pull all fuses except control fuses. On units supplied with circuit breakers, open all breakers except for the transformer.

2.Add a jumper to the Fan Safety Switch between Common and Normal Open and disconnect the wire connected to the Normally Closed. Turn unit disconnect ON. (Fan operation not required.)

NOTE

The above allows the technician to use unit 24 VAC power and controls to open liquid line solenoid valve(s) and hot gas bypass solenoid valve(s) for the dehydration process. If no power is at the unit disconnect, the technician is to use a separate 24 VAC source rated at 75 VA and connect to the system liquid line solenoid valve(s) and hot gas bypass solenoid valve(s) directly.

3.Connect refrigeration gauges to the suction and discharge service valves of the compressor and open.

4.Attach a “jumper” hose from the Rotalock fitting on the outlet of the receiver and the Schrader fitting on the liquid header of the condenser. Front seat the Rotalock valve approximately two turns.

5.To energize the liquid line solenoid valve(s) through the control system, set the temperature setpoint (see operation manual) to 60°F (15°C) and set the % relative humidity setpoint higher than the conditioned room ambient to ensure that solenoid valves and hot gas bypass valves are open during the dehydration process.

6.Pressurize system circuit(s) to 150 PSIG (1034 kPa) by using dry nitrogen with a trace of refrigerant. Check system for leaks with suitable leak finder.

7.After completion of leak testing, release test pressure (per local code) and pull a vacuum on the system.

8.After 4 hours, check pressure readings and, if they have not changed, break vacuum with refrigerant. Pull a second and third vacuum of 250 microns or less. Recheck pressure after 2 hours.

3.5.4Charging

1.Make sure unit is OFF. Open all disconnect switches and, on units supplied with circuit breakers, open all breakers. Replace all fuses for the Fan and Compressors or close breakers.

2.Remove jumper on the Fan Safety Switch and reconnect the system wire connections. Ensure that all operational components are clear of debris. Turn unit ON. (Fan operation is required.) Check the evaporator fan for proper rotation and correct if necessary.

3.Connect the refrigerant gauge charging hose to the drum of refrigerant and to the suction and discharge service valves of the compressor(s).

4.Calculate the amount of charge for the system. Weigh in as much of the system charge as possible. Refer to the unit, condenser and refrigerant line charge tables.

5.Set the control temperature setpoint (see operation manual) to 60°F (15°C) and set the % relative humidity setpoint higher than the conditioned room ambient to ensure that solenoid valves and hot gas bypass valves are open during the charging procedure. You may have to bypass the

LP Switch (low pressure switch) to start the compressors and stop short cycling. Reset the Head Pressure switch(es) if open.

6.Add refrigerant (R407C liquid or R22 vapor per unit nameplate) to the suction side of the compressor until there is sufficient pressure to energize the low pressure switch.

NOTE

When adding refrigerant to an operating system, it may be necessary to add the refrigerant through the compressor suction service valve. Because the refrigerant leaving the refrigerant cylinder must be in a liquid state, care must be exercised to avoid damage to the compressor. It is suggested that a sight glass be connected between the charging hose and the compressor suction service valve. This will permit adjustment of the cylinder hand valve so that liquid can leave the cylinder while allowing vapor to enter the compressor.

Then you may remove the manual bypass you applied earlier.

7.Charge the unit until the proper charge is weighed in.

Table 10 Refrigerant control settings psi (kPa)

Low Pressure Cut Out	Low Pressure Cut In	High Pressure Cut Out

20 (137.9)	65 (448.2)	360 (2482)

ITR specifications

The Liebert ITR is an advanced precision cooling unit designed to maintain optimal temperature and humidity levels in mission-critical environments. Engineered for high-performance applications, it is particularly suitable for data centers, telecommunications facilities, and other spaces that require precise climate control to ensure uninterrupted operation of sensitive equipment.

One of the main features of the Liebert ITR is its modular design. This allows for scalability and flexibility, enabling users to customize the system based on their specific cooling needs. The unit can be configured in various sizes and cooling capacities, making it suitable for both small server rooms and large data centers. This adaptability is crucial for organizations that anticipate growth and require an efficient cooling solution that can evolve with their infrastructure.

The Liebert ITR incorporates state-of-the-art technologies to enhance performance and energy efficiency. Among these technologies is the use of a variable speed compressor that adjusts its speed based on the cooling load. This capability not only improves energy efficiency but also significantly reduces operational costs by minimizing electricity consumption when cooling demands fluctuate.

Additionally, the unit features advanced control systems that provide intelligent monitoring and management of temperature and humidity levels. These systems can integrate seamlessly with building management systems (BMS) and can be operated remotely, providing users with real-time insights into the performance of the cooling system. Such connectivity ensures quick identification and resolution of potential issues, thereby reducing downtime and maintaining optimal conditions for critical equipment.

The Liebert ITR utilizes eco-friendly refrigerants, contributing to reduced environmental impact while ensuring compliance with regulatory standards. The unit's design also emphasizes reliability, featuring robust construction and redundant components that enhance longevity and minimize the likelihood of failures.

Furthermore, the Liebert ITR is equipped with advanced filtration systems that maintain air quality by reducing particulate matter and contaminants, ensuring that the atmosphere within data centers is not only cool but also clean—critical for the longevity of sensitive electronic equipment.

Overall, the Liebert ITR is characterized by its innovative design, energy-efficient operation, and comprehensive control capabilities, making it an ideal choice for businesses looking to safeguard their critical infrastructure from overheating and humidity. As climate control becomes increasingly important in the digital age, the Liebert ITR stands out as a reliable solution for maintaining optimal environmental conditions.

Liebert ITR Dehydration/Leak Test, Low Pressure Cut Out High Pressure Cut Out 360

Models: ITR