Liebert ITR Lee-Temp/Flood Back Head Pressure Control Systems, Charging, Piping

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Air-Cooled Models

3.4.3Charging

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.

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 liquid line sight glass becomes clear. Then add one additional pound of refrigerant.

8.As head pressure builds, the condenser fan starts rotating. The fan becomes fully energized when sufficient head pressure is developed. (Fan starts to rotate at 190 psi and is full speed at 250 psi.)

Table 9

Refrigerant control settings psi (kPa)

 

 

 

Low Pressure

Low Pressure

High Pressure

Cut Out

Cut In

Cut Out

20 (137.9)

65 (448.2)

360 (2482)

 

 

 

 

3.5Lee-Temp/Flood Back Head Pressure Control Systems

The Lee-Temp system consists of a modulating type head pressure control valve and insulated receiver with heater pad to ensure operation at ambient temperatures as low as -30°F (-34.4°C).

3.5.1Piping

Lee-Temp systems have two factory-supplied, field-installed check valves: one on the discharge side of the scroll compressor and one on the inlet side of the receiver. Be sure to install the check valves with the refrigerant flow in the proper direction. When soldering or brazing the valves, it is very important that the internal parts be protected by wrapping the valve with a damp cloth to keep the valve tem- perature below 250°F (121°C).

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Contents Liebert Challenger ITR Page Table of Contents R407C Refrigerant Chilled Water ModelsSplit System Models Figures Tables System Descriptions Equipment Inspection Remote Sensor Installation LocationRoom Preparation Location ConsiderationsRemoval of Skid Unit shipping weightsHandling With Skid Domestic Export Model Lb kg 50Hz Models 60Hz ModelsCabinet dimensions Unit WeightSL-11897 Piping connection size Piping ConsiderationsDrain Line Piping Outlet Locations Piping connections for split system fan coil units Piping connections for water/glycol and Glycool units Piping connections for chilled water self-contained units Electrical Connections Electrical connectionsDucted Applications Plenum InstallationBalancing the Air Distribution Checklist for Completed Installation Low Voltage Condenser LocationLine Voltage Lee-Temp/Flood Back Head Pressure Control CondensersAir-cooled condenser statistics 23 & 33 kW 067A 065A Refrigerant PipingRecommended line sizes OD copper inches Equivalent Length Hot Gas Line Liquid LineEquivalent lengths feet for various pipe fittings Fan Speed Control SystemsMaterials Supplied Condenser refrigerant per serial tagDehydration/Leak Test Single Circuit Shown Charging Refrigerant control settings psi kPaLee-Temp/Flood Back Head Pressure Control Systems PipingMaterials Supplied Low Pressure Cut Out High Pressure Cut Out 360 Single Circuit Shown Condenser Water-cooled general arrangement Water Regulating Valve Water Regulating Valve AdjustmentTesting Valve Function Water Regulating Valve Manual FlushingPump and Drycooler Drycooler InstallationDrycooler Location Expansion Tanks, Fluid Relief Valves and Other Devices Room dew point temperaturesGlycol Piping Dry Bulb Wet Bulb Relative Dew Point HumidityFilling Instructions Indoor unit glycol volume approximate gallons liters maxVolume in standard Type L copper piping Preparing the System for Filling@ 50F 10C Glycol SolutionsEthylene glycol concentrations Filling the System See Note 30-1/4 For expansion tank dimensions, see on43-9/16 110 5mm 483mm 43-3/16 1097mmGlycol pump data Mounting hole dimensional dataDrycooler data Pump Pump Suction Pump Discharge ConnectionGlycol general arrangement Glycool general arrangement Glycol Regulating Valve Adjustment Glycol Regulating ValveChilled Water Models Air-Cooled Condensing Units Water/Glycol-Cooled Condensing UnitsRefrigerant Loop Line coupling sizes Unit refrigerant chargeRecommended refrigerant lines R22 or R407C sizes OD copper Evaporator Evaporator Condensing UnitQuick Connect Fittings Unit Dimensions See Table Outdoor Air-Cooled Condensing UnitsPFH067A-L Outdoor air-cooled condensing unit-top air discharge models See Table152 Piping and electrical connections top air discharge36-1/4 38-1/2 Electrical field connections, prop fan condensing module SL-11081 PG 8ACentrifugal Air-Cooled Condensing Units Installing the Indoor Condensing UnitModel Net Weight 60 Hz 50 Hz Lb kg MC65A MC64A Indoor centrifugal condensing unitDucting Airflow CFM CMHCentrifugal air-cooled condensing unit dimensional data AIR Cooled Water Cooled Piping Considerations Regulating Valve Adjustment and TestingWater and Glycol-Cooled Condensing Units Condenser Water RequirementsWater/glycol-cooled condensing unit dimensions WATER/GLYCOL Temperature Gauge Pressure Psig KPa R407C RefrigerantExample Temperature Pressure Gauge Psig KPaCalculating Subcooling Ti n Ne tIti That

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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