Data Aire gForce Ultra User manual

User Manual
DX, Single and Dual Circuit
36, 45, 56, 70 and 106 kW
Air and Water/Glycol Cooled

2 ● gForce Ultra User Manual 10-2014
CONGRATULATIONS ON THE SELECTION OF A DATA AIRE
PRECISION ENVIRONMENTAL CONTROL SYSTEM. PROPER
INSTALLATION, OPERATION AND MAINTENANCE OF THIS
EQUIPMENT WILL ENSURE YEARS OF OPTIMAL PERFORMANCE.
There are separate User Manuals for other components of your Data Aire precision
environmental cooling system including dap4™, condenser/condensing unit and fluid
cooler.
NOTE: This manual is intended to assist trained service personnel by
providing necessary guidelines for this particular equipment. Service to Data
Aire units should be done by qualified individuals with an adequate
background in areas such as HVAC, electrical, plumbing and electronics, as
applicable.
WARNING: Service performed by unauthorized or unqualified technicians
may void manufacturers’ warranties and could result in property damage
and/or personal injury.
NOTE: Special care should be given to those areas where these
symbols appear.
Data Aire, Inc. reserves the right to make design changes for the purpose of
product improvement or to withdraw any design without notice.

10-2014 gForce User Manual ● 3
Table of Contents
1. INTRODUCTION.................................................................................................7
1.1 Product Information .............................................................................................. 7
1.2 Model Identification .............................................................................................. 8
1.3 Inspection ............................................................................................................ 8
1.4 Paperwork............................................................................................................ 9
2. INSTALLATION ................................................................................................10
2.1 Installation Checklist ............................................................................................10
2.2 Room Considerations............................................................................................10
2.3 Equipment Handling.............................................................................................11
2.4 Rigging ...............................................................................................................11
2.5 Locating the Unit .................................................................................................12
2.5.1 Downflow Units ....................................................................................12
2.5.2 Upflow Units.........................................................................................13
2.6 Storage...............................................................................................................14
2.7 Piping .................................................................................................................14
2.7.1 Air Cooled Unit Piping ...........................................................................15
2.7.2 Discharge Lines ....................................................................................16
2.7.3 Liquid Lines..........................................................................................17
2.7.4 Connection Sizes, Air Cooled Units .........................................................17
2.7.5 Field Piping, Remote Condenser ............................................................18
2.7.6 Water/Glycol Cooled Unit Piping ............................................................18
2.7.7 Field Piping, Water/Glycol System..........................................................20
2.7.8 Connection Sizes, Water/Glycol Cooled Units ..........................................21
2.7.9 Connection Sizes, Fluid Coolers..............................................................21
2.7.10 Auxiliary Chilled Water/Energy Saver Coil Piping ..................................21
2.8 Condensate Drain Piping.......................................................................................21
2.9 Humidifier Piping .................................................................................................23
2.9.1 Steam Generator Humidifier ..................................................................23
2.10 Leak Testing........................................................................................................23
2.11 Evacuation ..........................................................................................................24
3. ELECTRICAL CONNECTIONS .............................................................................26
3.1 Electrical Service..................................................................................................26
3.2 Nameplate Ratings...............................................................................................26
3.3 Grounding ...........................................................................................................27
3.4 Voltage Tolerance ................................................................................................27
3.5 Auxiliary Control Wiring ........................................................................................27
3.6 Remote Shutdown ...............................................................................................27
3.7 Remote Alarm Contacts ........................................................................................28
3.8 Condensate Pumps ..............................................................................................28
3.9 Condensate Probe................................................................................................29
3.10 Water Sensing Cable (Optional).............................................................................29
3.11 Remote Temperature and Humidity Sensors (Optional) ...........................................30
3.12 Manual Override Switches.....................................................................................30

4 ● gForce Ultra User Manual 10-2014
3.13 Wiring Diagrams ..................................................................................................31
4. INSTALLATION OF REMOTE OUTDOOR HEAT EXCHANGER ................................32
5. CHARGING.......................................................................................................32
5.1 General Charging Guidelines .................................................................................32
5.2 Voltage Phase Check ............................................................................................32
5.2.1 Evaporator ...........................................................................................32
5.2.2 Secondary Heat Exchanger....................................................................33
5.2.3 Fan Speed Control System ....................................................................34
5.3 Air Cooled Systems ..............................................................................................34
5.3.1 Charging ..............................................................................................34
5.3.2 Flooded System Charging......................................................................37
5.4 Water/Glycol System............................................................................................41
5.4.1 Water/Glycol Cooled System Charging ...................................................41
5.5 Check a Running Compressor................................................................................42
5.6 Refrigerant Handling ............................................................................................42
5.7 Commissioning ....................................................................................................43
5.8 Important Refrigeration Components.....................................................................43
5.8.1 Variable Capacity Compressor with VFD .................................................43
5.8.2 Electronic Expansion Valve ....................................................................44
5.8.3 High Pressure Cutout Switch .................................................................44
5.8.4 Low Pressure Cutout Switch ..................................................................44
5.8.5 Liquid Line Solenoid Valve .....................................................................44
6. GLYCOL SYSTEMS ............................................................................................46
6.1 Glycol Concentration ............................................................................................46
6.2 Internal (Fluid) Volume –Downflow Units ..............................................................46
6.3 Internal (Fluid) Volume –Upflow Units ..................................................................46
6.4 Internal (Fluid) Volume –Fluid Coolers ..................................................................47
6.4.1 Fluid Cooler Information........................................................................47
7. Variable Speed Compressor...............................................................................48
7.1 Features..............................................................................................................48
7.2 Oil Management ..................................................................................................48
7.3 Crankcase Heaters ...............................................................................................48
7.4 Oil Level..............................................................................................................49
7.5 VFD Drive............................................................................................................50
7.5.1 Local Control for Charging.....................................................................51
7.5.2 View Drive Alarms ................................................................................52
8. CONTROLS ......................................................................................................53
8.1 dap4™ Microprocessor Control Panel .....................................................................53
8.1.1 Control Module .....................................................................................53
8.1.2 Display Module .....................................................................................54
8.1.3 Buttons ................................................................................................54
8.1.4 Accessing Menus/Passwords..................................................................54
8.1.5 Changing the Service Level Password.....................................................56
8.2 Entering Menu Settings ........................................................................................56

10-2014 gForce User Manual ● 5
8.2.1 Menu A –ON/OFF.................................................................................57
8.2.2 Menu B - Setpoints ...............................................................................58
8.2.3 Menu C –Clock/Scheduler.....................................................................62
8.2.4 Menu D –Input/Output.........................................................................62
8.2.5 Menu E –Historical Data .......................................................................62
8.2.6 Menu F –Information ...........................................................................65
8.2.7 Menu G –Network Config .....................................................................65
8.2.8 Menu H –Calibrate Sensors...................................................................68
8.2.9 Menu I –Manual Control.......................................................................71
8.2.10 Menu J –Factory Settings ..................................................................75
8.2.11 Menu K –Alarms & Limits ..................................................................88
8.2.12 Menu L –Configure I/O .....................................................................99
8.2.13 Zone Master ......................................................................................99
8.3 Secondary Heat Exchangers..................................................................................99
9. Control Logic.................................................................................................. 100
9.1 Fan Control Logic...............................................................................................100
9.1.1 Fan Speed Modulation to Rack Temperature (Mod to Rack): ................. 100
9.1.2 Fan Speed Modulation Proportional to Cooling Demand (Mod to Comp): 101
9.1.3 Fan Speed Modulation to Return Air (RA) Temperature (Mod to RetT): .. 101
9.1.4 Fan Speed Modulation to Constant Static Pressure (Air Pressure): .........101
9.1.5 Fan Speed Modulation based on BMS (BMS Speed): ............................. 101
9.1.6 Constant Fan Speed (Const Speed):..................................................... 102
9.2 Compressor.......................................................................................................102
9.2.1 Return Air Temperature Control Mode.................................................. 102
9.2.2 Discharge Air Temperature Control Mode .............................................107
9.3 Safeties and Alarms ...........................................................................................110
9.4 Dehumidification Mode .......................................................................................112
9.4.1 Relative Humidity Control Mode........................................................... 113
9.4.2 Dewpoint Control Mode....................................................................... 115
10. REGULAR MAINTENANCE ITEMS................................................................... 118
10.1 Air Filters ..........................................................................................................118
10.2 Fuses................................................................................................................118
10.3 Electric Reheat ..................................................................................................119
10.4 Humidifier .........................................................................................................119
10.4.1 Humidifier Canisters......................................................................... 119
10.5 Refrigerant Filter Drier........................................................................................119
10.6 Current Sensing Relay ........................................................................................120
10.7 Plug Fans ..........................................................................................................122
10.7.1 Electronically Commutated Motors .................................................... 122
10.7.2 Testing ........................................................................................... 124
11. RECOMMENDED LINE SIZING....................................................................... 125
11.1 Hot Gas Lines –Single Circuit Units (Up To 200 Equivalent Feet (61 m)) ................125
11.2 Hot Gas Lines –Dual Circuit Units (Up To 200 Equivalent Feet (61 m))...................125

6 ● gForce Ultra User Manual 10-2014
11.3 Liquid Lines –Single Circuit Units (Up to 200 Equivalent Feet (61 m)) ....................125
11.4 Liquid Lines –Dual Circuit Units (Up to 200 Equivalent Feet (61 m)) ......................125
12. CONTACT DATA AIRE .................................................................................. 126
13. MAINTENANCE/INSPECTION CHECKLIST ...................................................... 127

10-2014 gForce User Manual ● 7
1. INTRODUCTION
1.1 Product Information
The Data Aire gForce Ultra environmental control, direct expansion, single and dual
circuit Computer Room Air Conditioner (CRAC) equipment provides a high sensible
cooling, is self-contained, factory assembled, piped, wired, and factory tested prior to
shipment. These units include an enclosure/cabinet assembly, fan section, filter section,
cooling coil, controls, and interconnecting piping internal to unit.
The Data Aire CRAC unit provides cooling, reheat, humidification, dehumidification and
air filtration. The unit is provided with a Data Aire dap4™ microprocessor controller for
precision control. The unit must be operated in a conditioned space within the
operating envelope ASHRAE recommends for data centers. Maximum dew point is 59°F
(15°C). Operating outside this envelope can alter the operating performance and
decrease equipment reliability. Return air to the unit must be no cooler than the
ASHRAE recommendation of 68°F (20°C) DB and 40% RH or minimum WB of 54°F
(12.2°C) for proper unit operation. Operating below this can alter the operating
performance and decrease equipment reliability. Refer to ASHRAE’s publication,
“Thermal Guidelines for Data Processing Environments.”
The unique feature of the gForce Ultra is the application of variable capacity
compressors. The quest for greater energy efficiency is continuous; efficiency
benchmarks are always moving up. That's why Data Aire is moving toward variable
capacity compressor technology for quieter, more energy-saving performance.
Conventional compressors are designed to run at constant speed to handle a given
capacity requirement. But in data center applications, the capacity requirement varies.
In these situations, a constant speed compressor uses various capacity-regulation
techniques and can be less efficient than a compressor utilizing variable capacity
technology. A variable capacity compressor (VCC), on the other hand, saves energy
and operates more quietly by varying speed to match the workload. Tests with VCC
compressors have shown an immediate energy savings and sound level reductions.

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1.2 Model Identification
GU X X - XXX X X
│ │ │ │ │ │
gForce Ultra, │ │ │ │ │ │
Single and Dual Circuit
────
┘ │ │ │ │ │ Voltage
│ │ │ │ │ 2 - 208/230 VAC
A- Air Cooled │ │ │ │ └
────
4 - 460 VAC
W - Water Cooled
────
────
┘ │ │ │
G - Glycol Cooled │ │ │
│ │ │ Phase
D - Downflow
────
────
────
┘ │ └
────
────
3 - Three phase
U- Upflow │
│
Nominal Kilowatts │
036 kW │
045 kW │
056 kW
────
────
────
────
┘
070 kW
106 kW
gForce Ultra Model Number
1.3 Inspection
This Data Aire CRAC unit has been factory run-tested and has gone through a
comprehensive inspection prior to its packaging and shipment to ensure that it arrives
in excellent condition. However, shipping damage can occur and a visual inspection of
the outer crating immediately upon delivery should be performed. Upon arrival of the
unit and before unpacking it, verify that the labeled equipment matches the bill of
lading.
Note: any external damage or transportation damage on the freight
carrier’s forms. Inspect the unit itself for internal damage. A claim should
be filed with the shipping company if the equipment is damaged or
incomplete.

10-2014 gForce User Manual ● 9
Loose items such as remote control panels, disconnect switch handles, and spare air
filters are packed inside the unit. Refer to the yellow shipping tag located on the unit
door for details.
NOTE: Freight damage claims are the responsibility of the purchaser.
Action to recover losses should be filed immediately. Please notify factory
personnel of any claims.
1.4 Paperwork
Each Data Aire CRAC unit ships with a start-up sheet that should be completed during
installation. Also included in the paperwork is a warranty/information packet that
provides important wiring diagrams, specific component literature, warranty registration
cards and other valuable paperwork, including a copy of this User Manual.
A yellow tag is attached to the outside decorative door to indicate articles that may
have been packaged and shipped loose within the unit cabinet. Typically this would be
jackstands, condensate pumps and other loose components that are not factory
mounted.
WARNING: It is the responsibility of the installing contractor to return
the start-up sheet and warranty registration card to Data Aire for proper
activation of the unit warranty. Failure to do so may cause delays and
some cases void the warranty.

10 ● gForce Ultra User Manual 10-2014
2. INSTALLATION
NOTE: There is no intent on the part of Data Aire, Inc. to define local
codes or statutes which may supersede common trade practices. The
manufacturer assumes no responsibility for their interpretation. Consult
local building codes and National Electrical Code (NEC) for special
installation requirements.
2.1 Installation Checklist
As a precaution, review the following checklist to ensure proper operation:
Check for any damage
Check all wiring connections
Filters are properly positioned in air intake
WARNING: Before removing from the packaging inspect the unit for any
damage. Report any damage to the carrier and file a damage claim.
2.2 Room Considerations
Precision air conditioning equipment is designed to control spaces within close
tolerances of temperature and humidity. However, the room must be built with a
proper vapor barrier. A film of polyethylene is often used on walls and ceilings. Walls
and floors must also be painted with vapor-seal paint. Failure to provide a vapor barrier
can compromise space conditions.
Introduction of outside air into the space should be minimized. Outside air in excess of
5% of the total circulated air volume can have a significant effect on the overall space
conditions and result in poor space control.
Install the units as close as possible to the largest heat load.

10-2014 gForce User Manual ● 11
2.3 Equipment Handling
WARNING: Only properly trained personnel wearing appropriate safety
headgear, gloves, shoes and glasses should attempt to move the unit, lift it,
remove packaging or prepare the unit for installation.
Move the unit in its upright position to the installation site using a forklift or pallet jack.
It is recommended that the unit be protected from damage to the decorative doors
during any storage or moving.
Keep tines of the forklift level and at a height suitable to fit below the skid and/or unit
to prevent exterior and/or underside damage. Make sure the forks are spread to their
widest allowable width for proper balance. Do not lift the unit any higher than 4 inches
(100mm) off the ground. If necessary to lift higher than the suggested 4 inches
(100mm), exercise great care to ensure proper handling of the unit.
Personnel not involved with the lifting of the unit should keep a safe distance from the
unit.
The unit may be too tall to fit through a doorway while on the skid. Measure the unit
and doorway heights and refer to the installation plans to verify clearances prior to
moving the unit.
WARNING: Use care when moving. Improper handling could result in
injury. Proper care should be taken when uncrating the unit. The
packaging has wrapping bands with sharp edges that are under tension,
crating has staples and splinters. Proper protective equipment should be
worn by qualified personnel.
2.4 Rigging
Move the unit in its upright position to the installation site. It is recommended that the
unit be protected from damage to the decorative doors during any storage or moving.
Removal of the decorative doors is easily accomplished and may be done without
moving the equipment.
The shipping skid should be left in place if the unit is being moved with a forklift. If the
unit is being lifted, use spreader bars to prevent damage to the doors and panels.
The unit has 3/4” (19mm) holes in the shipping skid to which casters with 3/4” (19mm)

12 ● gForce Ultra User Manual 10-2014
stems can be attached. This allows easy movement down halls, into elevators and
through doorways. If clearance is a problem the casters may be inserted directly into
the bottom of the 1” (25mm) tubular steel corner posts at the bottom of the unit.
WARNING: Improper lifting or moving of the equipment may result in
damage to the decorative doors, panels or frame members.
2.5 Locating the Unit
Verify that the floor is level, solid and sufficient to support the unit. When installing the
unit, sufficient space must be allowed for airflow clearance, wiring, plumbing and
service access. It is recommended that each side and front have a clearance of at least
36” (914mm) to allow the doors to swing open and for servicing the unit.
The doors on some sides may not require as much service clearance. Refer to the
particular unit component breakdown drawings for assistance. Rear clearance is not
required, but 1” to 2” (25 to 50mm) of clearance is suggested.
For the best air distribution, the unit should be centered against the longest wall,
distributing the cold air as close to heat load as possible, unless the unit is ducted. The
unit should not be placed near any corner of the room or at the end of a long, narrow
room. Install the units as close as possible to the largest heat load. Multiple units
should be evenly spaced, as far apart as possible. It is recommended to install an
under-floor water detection system.
Note: Condensation formation and frequent humidifier flushing are
normal functions of this equipment. Proper drain connections must be
made to ensure proper removal. Unit will require water connections for
condensate removal and possibly for humidifier makeup water, chilled
water and/or hot water. Installation of units above equipment that could
sustain water damage should be avoided.
2.5.1 Downflow Units
Downflow units will typically sit on an elevated flooring system known as a raised floor.
The unit discharges air downward which pressurizes the raised floor and channels
upward through perforated floor tiles. Location and quantity of perforated tiles will
dictate proper air distribution. If the raised floor is strong enough to support the unit

10-2014 gForce User Manual ● 13
and local codes permit, the unit can be placed directly on top with cutouts made for the
discharge openings.
Verify that the raised floor has been properly sized for the unit’s airflow and the room is
free of airflow restrictions. Perforated floor tiles in the raised floor should ensure
minimal pressure loss. The raised floor must provide a minimum of 12" (305 mm)
clearance. Ensure that there is adequate clearance above the unit for service, such as
replacing filters. Optional plenums are available for downflow unit ducting.
There may be additional support required in the form of adjustable jackstands. These
are adjustable, threaded leveling rods which support the unit in each of the corners and
in the center on longer length units. Tighten the locknuts provided with each
jackstand. The base plate can rest on the floor or on vibration pads.
Floorstands are also a way of supporting the unit. These are ordered to the height of
the raised floor with leveling rods to allow adjustment. The floorstand has lips in each
corner to align with the unit which is placed on top. It is recommended that the unit
frame be bolted or screwed to the floorstand from below. Local building codes may
dictate this procedure. After installation, the raised floor is typically built around the
unit.
The raised floor serves as the distribution plenum for air on downflow units. Cables,
piping, wiring raceways, inadequate floor height and any other restrictions can inhibit
proper airflow. Care should be taken to avoid restrictions.
2.5.2 Upflow Units
Upflow units will typically be supported by vibration isolation pads and/or floorstands
which may also include leveling screws. An air discharge plenum may be factory
provided which ships loose and must be attached at the top of the unit frame. For in-
room applications with supply and return grilles, several feet of clearance must be
maintained at the intake and discharge of the unit.
Alternately, an air distribution plenum must be field fabricated with supply grilles to
distribute the air. Units are shipped with Electronically Commutated (EC) motors often
referred to as “plug fans”. Fan speed is factory set based on order. Fan speed can be
changed in 1% increments through the unit’s microprocessor controller, Data Alarm
Processor 4™(dap4™) by several different methods. See the dap4™User Manual for
details and recommended settings.

14 ● gForce Ultra User Manual 10-2014
WARNING: Do not operate upflow units without installing a plenum,
ductwork or guard over the fan opening(s) on the top surface of the
cabinet. Ductwork must be connected to the fan(s), or a plenum must be
installed on the top of the cabinet for protection from rotating blower
wheel(s) on upflow units. Risk of high-speed moving parts can cause injury
or death. Disconnect all local and remote electric power supplies before
working in the unit.
Note: Seal openings around piping and electrical connection to prevent
air leakage. Failure to do so could reduce the unit’s cooling performance.
2.6 Storage
Your Data Aire equipment comes ready for immediate installation. In some instances it
may be necessary to store the equipment for a period of time. If you must store the
equipment it should be done in a dry area, out of the weather, protected from damage
by other equipment in storage or transportation equipment, never stacked, and avoid
frequent relocation.
If equipment is stored for longer than 30 days special precautions must be taken to
avoid coil damage. All coils should be charged and sealed with a low pressure (i.e., 1 to
3 PSIG, (7 to 21 kPa)) inert gas, such as nitrogen. This prevents contaminates from
entering the coils: then when the seal is broken at installation, the rush of escaping
gas verifies the coil is leak free. If coils are not charged and sealed condensation mixes
with air pollutants forming a weak acid and over time can cause pin hole leaks to
develop in the coil tubes.
When equipment is installed after storage, caution should be taken to inspect and
replace, if required, rubber components. All moving parts, such as fans and motors,
should be hand tested to ensure that they are free and clear prior to start-up. Finally,
verify that all lubrication fresh and full.
2.7 Piping
Proper piping practices should be employed to ensure adequate oil return, even under
minimum load conditions with special consideration given to the size and proper slope
of the tubing coming from the evaporator. Tubing returns from the evaporator should

10-2014 gForce User Manual ● 15
be designed so as not to trap oil and to prevent oil and refrigerant migration back to
the compressor during off-cycles.
Piping should be designed with adequate three-dimensional flexibility. It should not be
in contact with the surrounding structure, unless a proper tubing mount has been
installed. This protection proves necessary to avoid excess vibration, which can
ultimately result in connection or tube failure due to fatigue or wear from abrasion.
Aside from tubing and connection damage, excess vibration may be transmitted to the
surrounding structure and generate an unacceptable noise level within the structure as
well.
When piping, use copper tubing with appropriate supporting devices (supporting
saddles, etc.). All field piping must be installed according to local codes. Avoid piping
runs through noise-sensitive areas, such as office walls and conference rooms. Refer to
Section 9.0 - Piping for piping guidelines and to the ASHRAE Refrigeration Handbook for
general, good-practice refrigeration piping.
All piping below the raised floor must be located so that it does not restrict airflow.
Plan the piping layout under the raised floor to prevent the airflow from being blocked.
When installing piping on the subfloor, it is recommended that the pipes be mounted in
a horizontal plane rather than stacked one above the other. Whenever possible, the
pipes should be run parallel to the airflow.
Ensure that the tubing surfaces to be brazed are clean and that all burrs have been
removed from the ends of the tubes. Ensure that all loose material has been cleaned
from inside the tubing before brazing. Keep piping clean and dry, especially on units
with R-410A refrigerant.
The units may be ordered with top or bottom connections.
2.7.1 Air Cooled Unit Piping
Air-cooled unit piping is crimped and brazed closed from the factory and contains a
nitrogen holding charge. Each installation requires field-supplied refrigerant piping to a
condenser.
Refer to section RECOMMENDED LINE SIZING charts on page 125 for a guideline on
sizing refrigerant lines. The ultimate responsibility for line size selection is that of the
installing contractor or project engineer. Data Aire does not assume this responsibility.

16 ● gForce Ultra User Manual 10-2014
The chart covers distances up to 200 equivalent feet (61 m). For installations beyond
this distance, consult ASHRAE or similar references.
Note: Standard piping practice must be used to ensure proper oil return
and efficient operation. The interconnecting lines to the remote air cooled
condenser or condensing unit must be installed by a qualified refrigeration
mechanic.
2.7.2 Discharge Lines
Discharge lines, also called hot gas lines, should be trapped at the top (inverted) and
bottom as well as every 15 to 20 feet (4.6 to 6.1 m) of vertical rise. Discharge check
valves (field provided) are recommended on all installations, especially those where
there are long pipe runs or cold climates. Check valves should be installed no less than
six (6) to ten (10) feet (1.8 to 3.1 m) from the compressor. The evaporator section
ships with a nitrogen holding charge. Do not vent the evaporator until all refrigerant
piping is in place, ready for connection to the evaporator and condenser. The
discharge, suction and liquid lines need to be refrigerant grade copper and in
accordance with local code. All refrigeration piping should be installed with high
temperature brazed joints. When brazing, a supply of nitrogen gas needs to be fed
through the refrigerant lines. Be sure to open the other end of the refrigerant line to
allow the nitrogen to bleed off and not pressurize the piping. Prevailing good
refrigeration practices should be employed for piping support, leak testing, dehydration
and charging the refrigerant circuits. During the installation, the lines should be capped
off and filled with dry nitrogen at the end of each day’s work or until the system is
completed and sealed.
Data Aire recommends a silver/phosphorus/copper alloy with 5 to 15% silver be used to
braze the refrigerant line sets to the indoor and outdoor units. Nitrogen needs to be
flowing through the lines to eliminate carbon deposit build-up on the inside of the
joints. Carbon could contaminate the refrigerant and restrict the metering device.
Piping must be supported within 18” (457 mm) of the inlet and outlet connections
external to the unit. Internal to the unit, the inlet connection is located on the top
header of all units. The discharge outlet is located at the bottom of the header.
Discharge line pressure should not exceed 9 PSI (62 kPa) for R-410A. Recommended
gas velocity for proper oil return is 1,000 FPM (5.1 m/sec). Slope horizontal lines
downward in the direction of the refrigerant flow. The recommended slope is 1/2” (12

10-2014 gForce User Manual ● 17
mm) for every ten (10) feet (3 m) of line length. Discharge lines do not require
insulation but due to the high temperatures of the refrigerant inside the line, the pipes
may be insulated to protect against burns to individuals near or around the lines.
2.7.3 Liquid Lines
Liquid line size is determined by pressure drop and velocity. The liquid line pressure
drop should not exceed 9 PSI (62 kPa) for R-410A. The recommended gas velocity
should be between 200 and 300 FPM (1 to 1.5 m/sec). To avoid excessive liquid line
pressure drop, the air cooled condenser should be located above or at the same level as
the evaporator. Condenser installation more than ten (10) feet (3.1 m) below the
evaporator is not recommended. Insulation of liquid lines is not required but can be
useful in preventing condensation from forming and to avoid flashing on long pipe runs.
2.7.4 Connection Sizes, Air Cooled Units
Model Number
Liquid Line
Hot Gas Line
GUA* 036
7/8 (22 mm) O.D.
7/8 (22 mm) O.D.
GUA* 045
7/8 (22 mm) O.D.
7/8 (22 mm) O.D.
GUA* 056
7/8 (22 mm) O.D.
7/8 (22 mm) O.D.
GUA* 070
7/8 (22 mm) O.D.
7/8 (22 mm) O.D.
GUA* 106
1-3/8 (35 mm) O.D.
7/8 (22 mm) O.D.
* D=Downflow U=Upflow
Note: Field connections at the indoor evaporator and remote condenser
or condensing unit will not necessarily be the same as the field pipe size
required. In some cases these will vary significantly.

18 ● gForce Ultra User Manual 10-2014
2.7.5 Field Piping, Remote Condenser
2.7.6 Water/Glycol Cooled Unit Piping
Water/Glycol-cooled units are factory-charged and tested. Field-supplied and field-
installed piping is required from the unit to building water or tower water sources or the
fluid cooler (i.e., dry cooler) and pump package. Pipe size will depend on length of run
and the maximum water flow required.
The required field installed fluid cooler pipe sizes may or may not be the same as the
connection sizes on the fluid cooler (refer to the Fluid Cooler User Manual for
connection sizing). This will depend on the length of pipe and the calculated pressure
drop of peripheral components.
Shutoff valves (field provided) should be installed within a few feet of the inlet and
outlet connections of the evaporator to allow the unit to be isolated for service.

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Drain/fill valves (field provided) should be located at the lowest point on the connected
piping.
Water/glycol cooled units are shipped with plate/fin heat exchangers as standard
equipment. A strainer (Data Aire provided) is shipped loose and is to be field installed
in the supply line with shut-off valves (field provided) before and after the strainer. The
strainers and water/glycol piping must be cleaned on a periodic basis. If the unit is
shipped with optional shell and tube condensers, strainers are not required and not
shipped with the unit.
All water pipes have a cap installed on the end of the pipe prior to shipment from the
factory for pressure testing the system. These caps need to be removed before
installing the piping to the units. Use a tube cutter for smaller pipes and a reciprocating
saw with a metal cutting blade for larger pipe sizes or if there is a clearance problem.
All connections need to be cleaned before connections are brazed together.
Note: One of the most common problems in a water/glycol system is the
presence of air in the condenser water loop. Air vents must be installed in
various locations the piping system to purge the air.
The water/glycol system may include a centrifugal pump (or pumps, for redundancy)
available from Data Aire as an option, along with field provided union(s), shutoff valves,
check valve(s) and a flow switch (Data Aire option). Pumps must be primed before
operating per the pump manufacturer’s guidelines.

20 ● gForce Ultra User Manual 10-2014
2.7.7 Field Piping, Water/Glycol System