Air-Cooled Models

3.4.2Dehydration/Leak Test and Charging Procedures for R22 (standard) or R407C (Optional) Fan Speed Control Type Condenser

! CAUTION

All local codes for handling refrigerant must be followed.

NOTE

As R22 and R407C are similar in properties, proper safety equipment and proper refrigeration tools are required on both types. Check unit nameplate for correct refrigerant type before topping off or recharging a system.

NOTE

Refrigerant R407C uses a POE (polyol ester) lubricant. The R407C refrigerant must be introduced and charged from the cylinder only as a liquid.

NOTE

When installing field piping, care must be taken to protect all refrigerant lines from the atmosphere, especially when using refrigerants with POE oils. Do not allow the piping to stand open to air for more than 15 minutes. Units designed for R407C have a compressor which contains POE oil that is very hygroscopic; that is, it quickly absorbs water from the air. The longer the compressor piping is left open to air, the harder it will be to fully evacuate. If left open too long, the POE oil may need to be replaced before achieving the required vacuum level.

Dehydration/Leak Test

1.Make sure unit is OFF. Open all disconnects and remove 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. Open all compressor service valves.

4.To energize the liquid line solenoid valves through the control system power, 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 dehydration process.

5.Pressurize the 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.

6.After completion of leak testing, release the test pressure (per local code) and pull a deep vacuum on the system with a suitable pump.

7.After four hours, check the pressure readings, and if they have not changed, break vacuum with refrigerant. Pull another vacuum to 250 microns or less. Recheck the pressure after two hours. After completing this step, pressurize the circuits with refrigerant (R407C liquid or R22 vapor per unit nameplate) until suction and discharge pressures have equalized.

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Liebert ITR installation manual Dehydration/Leak Test
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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.
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