Component Operation and Maintenance

6.4Refrigeration System

Each month, the components of the refrigeration system should be inspected for proper function and signs of wear. Since, in most cases, evidence of malfunction is present prior to component failure, peri- odic inspections can be a major factor in the prevention of most system failures.

Refrigerant lines must be properly supported and not allowed to vibrate against ceilings, floors or the unit frame. Inspect all refrigerant lines every six months for signs of wear and proper support. Also inspect capillary and equalizer lines from the expansion valve and support as necessary.

Each liquid line has a sight glass that indicates liquid refrigerant flow and the presence of moisture. Bubbles in the sight glass indicate a shortage of refrigerant or a restriction in the liquid line. The moisture indicator changes from green to yellow when moisture is present in the system.

6.4.1Suction Pressure

Suction pressure will vary with load conditions. The low pressure switch will shut the compressor down if suction pressure falls below the cut-out setting. High suction pressure reduces the ability of the refrigerant to cool compressor components and can result in compressor damage. Minimum (pres- sure switch cut-out setting) and maximum (design operating) suction pressures are in Table 18.

Table 18 Suction pressures

 

Minimum

Maximum

 

PSIG (kPa)

PSIG (kPa)

System

R–22

R–22

Air w/FSC

15 (103)

90 (620)

(Fan Speed Control)

 

 

Air w/Lee-Temp Control

20 (137)

90 (620)

(Floodback head

 

 

pressure control)

 

 

Water Cooled

20 (137)

90 (620)

 

 

 

Glycol Cooled

20 (137)

90 (620)

 

 

 

6.4.2Discharge Pressure

Discharge Pressure can be increased or decreased by load conditions or condenser efficiency. The high pressure switch will shut the compressor down at its cut-out setting. Refer to Table 19, below.

Table 19 Discharge pressures

 

 

Discharge Pressure

System Design

PSIG (kPa)

 

 

Air Cooled

260 (1795)

 

 

Water/Glycol Cooled

65-75°F (18-24°C) fluid

210 (1450)

 

 

 

 

85°F (29°C) fluid

225 (1550)

 

 

 

 

115°F (46°C) fluid

295 (2035)

 

 

 

Maximum

330 (2275)

 

 

High Pressure Cut-Out

360 (2482)

 

 

 

6.4.3Superheat

Superheat can be adjusted by the Thermostatic Expansion Value (TEV). To determine superheat:

1.Measure the temperature of the suction line at the point the TEV bulb is clamped.

2.Obtain the gauge pressure at the compressor suction valve.

3.Add the estimated pressure drop between bulb location and suction valve.

4.Convert the sum of the two pressures to the equivalent temperature.

5.Subtract this temperature from the actual suction line temperature. The difference is superheat.

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Liebert 3000 manual Refrigeration System, Suction Pressure, Discharge Pressure, Superheat
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3000 specifications

The Liebert 3000 is a cutting-edge power protection solution designed to provide reliable and efficient backup power for critical applications. This uninterruptible power supply (UPS) system is engineered to safeguard sensitive electronic equipment from power disturbances, ensuring uninterrupted operations in data centers, telecommunications, and industrial environments.

One of the standout features of the Liebert 3000 is its high-efficiency design. With an efficiency rating of up to 94%, the system minimizes energy loss, resulting in lower operational costs and a reduced carbon footprint. This is particularly important in today's environmentally conscious climate, as organizations strive to meet sustainability goals while maintaining top-tier performance.

The Liebert 3000 employs advanced technologies to enhance its functionality. It incorporates online double-conversion technology, which provides a continuous supply of clean and regulated power. This technology ensures that connected loads receive stable voltage and frequency, shielding them from voltage spikes, sags, and outages. Additionally, the UPS offers features such as automatic battery testing, which helps ensure peak battery performance and reliability.

Another key characteristic of the Liebert 3000 is its modular design, allowing for flexible scalability. This means that organizations can easily expand the capacity of their UPS system as their power needs grow, without the need for extensive system overhauls. The modular architecture also facilitates simplified maintenance and reduces downtime, as individual modules can be serviced without interrupting power to the critical load.

The system is equipped with comprehensive monitoring and management capabilities. The Liebert 3000 provides real-time data on power usage, battery status, and system performance, enabling facility managers to make informed decisions and proactively address potential issues. The integration of remote management tools allows for seamless monitoring from anywhere, providing peace of mind for operators.

Overall, the Liebert 3000 combines high efficiency, advanced technology, and flexible design to deliver a robust power protection solution. Its reliability and performance make it a preferred choice for organizations seeking to protect their critical infrastructure while enhancing operational efficiency and sustainability. As businesses continue to rely on technology for their everyday operations, the Liebert 3000 stands out as a dependable safeguard against the uncertainties of power quality.
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