Precision Cooling for Business Critical Continuity Liebert Xtreme Density™ System Design Manual
TABLE OF CONTENTS 1.0 SYSTEM DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 1.1 Direct and Indirect System Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.2 Liebert XDO—Overhead Cooling Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.3 Liebert XDV—Vertical Above-Cabinet Cooling Module. . . . . . . . . . . . . . . . . . . . . . . . . . . .
FIGURES Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 Figure 20 Figure 21 Figure 22 Figure 23 Figure 24 Figure 25 Figure 26 Figure 27 Figure 28 Figure 29 Figure 30 Figure 31 Figure 32 Figure 33 Figure 34 Figure 35 Figure 36 Figure 37 Figure 38 Figure 39 Figure 40 Figure 41 Figure 42 Figure 43 Figure 44 Figure 45 Pressure enthalpy diagram - refrigerant. . . . . . . . . . . .
TABLES Table 1 Table 2 Table 3 Table 4 Table 5 Table 6 Table 7 Table 8 Table 9 Table 10 Table 11 Table 12 Table 13 Table 14 Table 15 Calculating quantity and spacing of XDO modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Determine required number of XDV modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Supply, return pipe sizes—equivalent lengths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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System Description 1.0 SYSTEM DESCRIPTION The Liebert XD™ family of cooling units delivers efficient, sensible cooling to high-heat environments. XD systems are designed to cool computer racks and hot zones in a data center or computer room without taking up expensive floor space for cooling components.
System Description 1.1 Direct and Indirect System Configurations Liebert XD systems are available in Direct and Indirect configurations—differentiated essentially by the location of the pumping unit (see Figures 2 and 3). The indirect system uses a pumping unit to control and circulate the XD Coolant™. In the direct system, the pumping functions are incorporated in the chiller.
System Description Figure 4 Suspended XDO modules in hot aisle-cold aisle arrangement Cold Aisle Hot aisles and cold aisles alternate, taking advantage of airflow properties to increase cooling efficiency 1.3 Hot Aisle Cold Aisle Hot Aisle Cold Aisle Liebert XDV—Vertical Above-Cabinet Cooling Module The XDV is installed on top of or above a rack enclosure. It is available with optional flexible metal pipes with automatic shutoff at the ends for easy connection to the XD Coolant distribution pipes.
System Description Figure 6 Top-mounted XDV modules with flexible piping in hot aisle-cold aisle arrangement Cold Aisle Hot Aisle Hot aisles and cold aisles alternate, taking advantage of airflow properties to increase cooling efficiency Cold Aisle Hot Aisle 4
System Description 1.4 Liebert XDP—Pumping Unit The XDP isolates the building’s chilled water circuit from the XD Coolant circuit. The XDP circulates coolant to XDV or XDO modules while preventing condensation by maintaining the coolant’s temperature above the dew point.The XDP employs two sets of remote sensors to determine the temperature and humidity in the air and instantly adjusts coolant supply temperature to compensate for changing conditions.
System Description 1.5 Liebert XDC—Chiller The XDC is an indoor chiller that connects directly to the XDO or XDV units and provides coolant circulation and control. The XDC keeps the XD Coolant temperature above the dew point and eliminates the need for a separate pumping unit in the direct system configuration. The XDC employs two sets of remote sensors to determine the temperature and humidity in the air and instantly adjusts coolant supply temperature to compensate for changing conditions.
System Description 1.7 Liebert XDA—Air Flow Enhancer The XDA is a fan unit that boosts the airflow through densely populated enclosures, removing hot spots from within the racks. One or two units can be mounted on most rack enclosures.
Starting a New Equipment Cooling Project 2.0 STARTING A NEW EQUIPMENT COOLING PROJECT 2.1 Determining Cooling Equipment Needs 1. Is there adequate space available for an XD installation? 2. Is the hot aisle/cold aisle approach being utilized for this room design or can it be utilized in this room design? 3. Is redundant cooling equipment required? 4. Are there access considerations for all components (possible rigging problems) 5.
Starting a New Equipment Cooling Project 2.2 Implementing a Hot-Aisle/Cold Aisle Design A best practice is to use rows of equipment racks in an alternating arrangement of “cold aisles” and “hot aisles.” This is best accomplished when the layout of the file-server farm area is first being planned. and it is exceedingly more difficult to accomplish when the computer room is already populated with operating hardware.
Designing a Liebert XD Solution 3.0 DESIGNING A LIEBERT XD SOLUTION Liebert XD systems are intended for use with precision air conditioning equipment, such as the Liebert Deluxe System/3 and Liebert DS. The precision air conditioning equipment is required to control the room’s humidity and to filter the air. The XD systems provide efficient, highly effective heat removal (sensible cooling only), and provide no dehumidification.
Designing a Liebert XD Solution 3.3 Selecting Liebert XDO or Liebert XDV Modules The next step is to select XDO or XDV cooling modules to be configured into the solution. An XDO and an XDV can be connected to the same XDP/XDC piping circuit. Generally, the XDO is selected for use in new installations or renovations where the unit can be installed on the ceiling or in the overhead space.
Designing a Liebert XD Solution Table 1 Calculating quantity and spacing of XDO modules Input Information Step Total heat load in the room, kW A Reserve capacity needed (10% to 25% of A is recommended) B Existing/planned Liebert Deluxe/DS unit sensible capacity D C Room area, square feet Required cooling capacity = A + B E Required XD system cooling capacity = C – D F Number of XDOs required = E ÷ 16, rounded up (60Hz) =E ÷ 14, rounded up (50Hz) G Number of XDP/XDC modules required = F ÷ 1
Designing a Liebert XD Solution 3.6 Liebert XDV Unit Placement XDV units should be placed on top of the cabinets that generate the greatest amount of heat. If heat loads are dispersed evenly throughout the room, the XDV modules may be spread out accordingly. The XDV must be placed toward the front of the equipment cabinet, so that its front bottom edge is flush with the front top edge of the cabinet. Placing the unit farther back on the top of the unit will restrict airflow into the cold aisle.
Designing a Liebert XD Solution 3.7 Liebert XDP/XDC Placement The XDP/XDC may be placed in the critical space or in an adjacent equipment room. The allowable distance between the XDP/XDC and its connected cooling modules is determined by the piping design and by the amount of coolant required. Refer to 3.9 - Liebert XD Coolant™ and 3.10 - Liebert XD Piping System Design. The maximum height of any of the main or connecting piping should be no more than 20 feet (6m) above the top of the XDP/XDC unit.
Designing a Liebert XD Solution Figure 15 XDV units mounted on racks emitting 5kW of heat top view Downflow Cooling Unit Downflow Cooling Unit XDVs Mounted on Equipment Racks Interlaced piping arrangement for enhanced protection Circuit 1 Circuit 2 Equipment Racks without XDVs Perforated Raised Floor Tiles Figure 16 XDV units mounted on racks emitting 8kW of heat top view Downflow Cooling Unit Downflow Cooling Unit XDVs Mounted on Equipment Racks Interlaced piping arrangement for enhanced prot
Designing a Liebert XD Solution Figure 17 XDV units mounted on racks emitting 16kW of heat top view Downflow Cooling Unit Downflow Cooling Unit XDVs Mounted on Equipment Racks Circuit 1 Circuit 2 Circuit 3 Interlaced piping arrangement XDOs Mounted for enhanced on Equipment Racks protection Circuit 4 Circuit 5 Circuit 6 16 Perforated Raised Floor Tiles
Designing a Liebert XD Solution 3.9 Liebert XD Coolant™ The coolant used in the XD system is HFC-134a (1,1,1,2-tetrafluoroethane), made by a number of manufacturers. The amount of coolant used by the XD system may be significantly higher than typical DX cooling systems. ! CAUTION The XD pumped R-134a refrigerant circuits do not use refrigerant oil. Do NOT put oil in the R-134a system. All the major components of an XD system must be installed in a space with a volume of at least 1,000 ft3 (28.
Designing a Liebert XD Solution The assembly and connection means used for piping in the XD system are similar to that of conventional refrigeration systems. Brazing material or soft solder may be used. However, if brazing material is used, the lines being brazed MUST be pressurized with flowing dry nitrogen during brazing to prevent excessive oxidation and scale formation inside the piping. Please see Table 3 below for recommended pipe sizes and Figure 19 for piping segment locations.
Designing a Liebert XD Solution 3.12 Bypass Flow Controllers To ensure the XDP/XDC pumps operate within the optimum range, some installations require one or more bypass flow controller(s). These devices are added to the field piping, and simulate the flow of additional cooling modules. Each bypass flow controller should be installed with one shutoff valve to allow the controller to be disabled when cooling modules are added to an XD system.
Designing a Liebert XD Solution 3.13 Determining Coolant Volume After the preliminary system design is completed, Tables 5, through 9 may be used to determine the amount of coolant required. Perform the calculation below for each XD system being configured. NOTE All lengths in the tables below—Tables 5 and 6 —are actual pipe lengths, not equivalent pipe lengths 3.13.1 Liebert XDP/XDC Pumped R-134a Circuit Volume Table 5 Coolant volume calculations – XDP/XDC with XDV systems 145 lb.
Designing a Liebert XD Solution 3.14 Liebert XDC DX R-407c Circuit Volume—Air Cooled Units Weigh in the calculated charge based on Tables 7, 8 and 9. Table 7 Indoor unit refrigerant charge—R-407C Model 60 Hz Charge/Circuit lb. (kg) XDC160 4.5 (2.0) Table 8 Outdoor condenser charge—R-407C Model Charge / Circuit, lb (kg) CDL830 182 (82.6) CSL616 254 (115.2) CSL415 182 (82.6) Table 9 3.15 Liquid line charge - R-407C refrigerant per 100 ft (30 m) of Type “L” copper tube O.D.
XD Overhead Cooling Module—Liebert XDO 4.0 XD OVERHEAD COOLING MODULE—LIEBERT XDO Standard Features XDO • Micro Channel Heat Exchanger—The Liebert XDO unit includes two all-aluminum micro channel heat exchangers. • Fan—Air is drawn in the sides of the unit through the heat exchangers, and is discharged by the fan to area below —XDO fan tray hinges down to allow access to replace or service all electrical components.
XD Overhead Cooling Module—Liebert XDO Figure 23 XDO16 internal mounting location 26-3/4" (679mm) 18-1/2" (470mm) REAR OF XDO16 7/8" (22mm) diameter mounting holes 1" (25mm) TOP VIEW 1" (25mm) 26-3/4" (679mm) 7/8" (22mm) diameter mounting holes FRONT OF XDO16 23 DPN000771 Pg. 5 Rev.
XD Overhead Cooling Module—Liebert XDO Figure 24 XDO top and front electrical access points Mounting Hole Knockouts for High-Voltage Wiring TOP OF XDO Mounting Hole FRONT OF XDO The low-voltage connection is present only if the XDO is equipped with the optional condensation detection system. 4.1 Liebert XD Vertical Top Cooler (XDV) 4.1.
XD Overhead Cooling Module—Liebert XDO 4.1.2 Optional Features Liebert XDV • Factory-Installed Flexible Piping (For use with prefabricated piping assemblies)—The Liebert XDV unit is available with two pre-attached and pre-charged flexible metal pipes for coolant supply and return. Each pre-attached flexible pipe has a threaded coupler that automatically shuts off, when disconnected. • External Mounting Brackets—The XDV can be suspended from the overhead building structure.
XD Overhead Cooling Module—Liebert XDO Figure 26 XDV dimensions with factory-installed flex pipe Depth, Top 39-1/2" (1003mm) Width 22-7/8" (581mm) Depth, Bottom 29-5/8" (752mm) Height 14" (355mm) Unit weight with hose and coupler: 82 lb. (37kg) DPN00772 Rev.
XD Overhead Cooling Module—Liebert XDO Figure 27 XDV electrical connections Rear of XDV Right side of XDV Condensate Detection Dry Contacts - low-voltage connections Primary Circuit Breaker IEC Primary and Secondary Power Inlet Secondary Circuit Breaker DPN000770, Page 3 Rev.
XD Overhead Cooling Module—Liebert XDO Figure 28 Suspending single XDV from Unistruts Bolt 3/8" -16; nut and washer provided in kit Unistrut (field-supplied) Bolt a bracket to each corner of the XDV Figure 29 Suspending single XDV from the roof structure 3/8"-16 all-thread bolts, field-supplied, typical Hanging XDV unit To prevent bypass air from recirculating through the XDV without it passing through the cabinet, this space between the hanging XDV and the cabinet must be blocked.
XD Overhead Cooling Module—Liebert XDO Figure 30 Alternative mounting methods—mounting multiple XDV units 3/8"-16 all-thread field-supplied, typical Unistrut, field-supplied Bolt, 3/8"-16, nut and washer factory-supplied Mount XDV hanger brackets with field-supplied 3/8"-16 all-thread DPN0007770 Rev. 3, Pg.
XD Overhead Cooling Module—Liebert XDO 4.2 Liebert XD Piping Dimensions and Features Figure 31 Five-port prefabricated piping for XDV modules Flow direction H L ODS ODR 120" (3048mm) nominal 24" (610mm) 24" (610mm) 24" (610mm) 24" (610mm) 4-5/8" (117mm) 8-3/8" (213mm) 8-5/16" (210mm) Table 10 Supply inch (mm) Return inch (mm) DPN000773 Rev. 2, Pg.
XD Overhead Cooling Module—Liebert XDO Figure 32 Two-port prefabricated piping for XDV modules Flow direction H L ODS ODR 96" (2438mm) nominal 24" (610mm) 48" (1219mm) 8-3/8" (213mm) 8-5/16" (210mm) Table 11 Supply inch (mm) Return inch (mm) Two-port prefabricated piping legend Branch Piping Standard Run Long Run* 2 Port 181399G2# 183167G2# Outside Diameter (ODS) Height (H) Length (L) Outside Diameter (ODR) Height (H) Length (L) 1-1/8 8 (203) 6-3/4 (171) 2-1/8 10 (254) 8-1/8 (207) 1-3/8 8
XD Overhead Cooling Module—Liebert XDO 4.3 Liebert XDP Standard Features • Heat Exchanger—Brazed plate design with interwoven circuiting constructed of stainless steel plates, copper brazed. • Pumps—Centrifugal type, end suction, canned rotor design. • Standard Control Processor—The standard control system is microprocessor-based with an external LCD numerical display to allow observation of specified adjustable functions.
XD Overhead Cooling Module—Liebert XDO Figure 33 XDP dimensions, access points and external features XDO/XDV Return 2-1/8" dia. XDO/XDV Supply 1-1/8" dia.
XD Overhead Cooling Module—Liebert XDO Figure 34 Front view of XDP and electrical enclosure Status Lamps Status Lamps Enclosure Cover Latch User User Interface Disconnect Switch Hazardous Voltage Enclosure Cover Interface Disconnect |Switch Enclosure Cover Latch Hazardous Voltage Enclosure Cover FRONT VIEW ELECTRICAL ENCLOSURE Front View of XDP Electrical Enclosure Figure 35 XDP electrical enclosure knockout locations for field wiring User Interface Wiring Temperature/Humidity Sensor Wiring XDP
XD Overhead Cooling Module—Liebert XDO Figure 36 XDP high voltage connections Customer Power Connection Power Block Transformer 2 Disconnect Switch Transformer 1 Circuit Breaker Fuse Block Contactor 35
XD Overhead Cooling Module—Liebert XDO 4.4 Liebert XDC Standard Features • Compressors—Scroll with a suction gas cooled motor, vibration isolators, thermal overloads, manual reset high-pressure switch and pump down low-pressure switch. • Refrigeration System—Dual refrigeration circuits each including liquid line filter dryers, refrigerant sight glass with moisture indicator, electronic control valve, adjustable externally equalized expansion valves and liquid line solenoid valves.
XD Overhead Cooling Module—Liebert XDO Figure 38 XDC piping locations Install replaceable filter dryer assembly in liquid supply line G Orientation and location determined by installer G - Supply to cooling units F - Return from cooling units 47" (1193.8mm) 44" (1117.6mm) 6" (152.4mm) 23" (5842mm) A - Hot gas refrigerant lines B - Liquid refrigerant lines DPN000768 Rev. 1, Pg.
XD Overhead Cooling Module—Liebert XDO Figure 40 XDC electrical enclosure knockout locations for field wiring Knockout for XDC Input Power Enclosure cover not shown for clarity.
XD Overhead Cooling Module—Liebert XDO Figure 42 XDC high voltage connections—secondary disconnect switch Compressor Fuse Blocks Power Block Power Connection From Primary Power Block Ground Lug Secondary Disconnect Switch Transformer 3 Relay Compressor Contactors Electronic Hot Gas Bypass Controllers Figure 43 XDC heat rejection electrical connection points HEAT REJECTION ELECTRICAL CONNECTION POINTS Field-supplied 24V.
XD Overhead Cooling Module—Liebert XDO Figure 44 XDC electrical enclosure knockout locations for ELV Figure 45 XDC ELV field connections points 40
Specifications 5.0 SPECIFICATIONS Table 12 Liebert XDO specifications Models Cooling Capacity, nominal Conditions XDO16BK--0, XDO16DK--0 (60Hz) XDO16BT--0, XDO16DT--0 (60Hz) XDO16BT--0, XDO16DT--0 (50Hz) 16kW / 4.6 Tons 16kW / 4.6 Tons 14kW / 3.
Specifications Table 13 Liebert XDC specifications Parameter Cooling Capacity, Nominal 60Hz Models 50Hz Models 46 tons / 160kW with 125ºF (51.6ºC) condensing temperature and 50ºF (10ºC) evaporating temperature 37 tons / 130kW with 125ºF (51.
Specifications Table 14 Liebert XDV specifications Number of models 8, based on input voltage, optional condensate sensing and flex hose option 8 kW / 2.2 Tons Cooling capacity, nominal 6.5 kW / 1.85 Tons Each capacity is based on 55ºF Entering Coolant Temperature, 92ºF Entering Air Temperature, 50ºF or lower dew point, rear inlet.
Specifications Table 15 Liebert XDP specifications Number of Models 4, based on input voltage and pump redundancy Cooling Capacity, Nominal 160 kW / 46 Tons, 60Hz 140 kW / 40 Tons, 50Hz Each capacity is based on 45ºF (7ºC) entering water temperature and 140gpm (530lpm) water flow rate. Capacity is reduced when glycol mixtures are used in place of 100% water.
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