Desert Aire GrowAire GS Series User manual

Indoor Air Quality
Aura™ (QS)
TotalAire™ (QS)
VerticalAire™ (QV)
Installation and Operation Manual
• Climate control
systems that provide
cooling, dehumidifi-
cation, and optional
auxiliary heating for
Controlled Environ-
mental Agriculture in a
single, highly efficient
package.
• The GrowAire®GA
Series climate control
system offers a
all-in-one packaged
rooftop configuration.
• The GrowAire®GS
Series climate control
system is available in
a wide range of indoor
and outdoor configura-
tions and sizes to
match the application
requirements.
• The GrowAire®GV
Series climate control
system is a high-quality
cost-effective system
designed for tight
spaces
GS Series™
GV Series™
GA Series™

2

3
DANGER
ONLY TRAINED, QUALIFIED PERSONNEL SHOULD INSTALL AND/OR SERVICE
DESERT AIRE EQUIPMENT. SERIOUS INJURY, DEATH AND PROPERTY DAMAGE CAN
RESULT FROM IMPROPER INSTALLATION/SERVICE OF THIS EQUIPMENT. HIGH VOLTAGE
ELECTRICAL COMPONENTS AND REFRIGERANT UNDER PRESSURE ARE PRESENT.
For any unit labeled Class 1, Group D, Division 2, all wiring must be in accordance to
Class 1, Group D, Division 2 requirements. Insure that all local, state, national and any
other applicable codes are adhered to when connecting any device to this equipment.
All electrical connections to units labeled Class 1, Group D, Division 2 must be done
with a conduit seal.
Desert Aire
Climate Control Equipment Standard Limited Warranty
Desert Aire warrants the climate control unit to be free from defects in materials and workmanship subject to the
terms, conditions and limitations stated herein.
TERMS
Desert Aire warrants all components (except as noted) for a period of two (2) years from the date of shipment. This
warranty shall be limited to the supply of new or rebuilt parts for the part which has failed because of
defects in workmanship or material, and does not include the cost for labor, transportation or other costs not herein
provided for. Replaced parts are warranted only for the remaining portion of the original warranty period.
CONDITIONS
The warranty is subject to the following conditions:
1. The unit must be properly installed and maintained in accordance with the Desert Aire
“Installation and Operation Manual” provided with each unit and/or other documentation provided.
2. The Start-Up Report must be completed and returned to Desert Aire Service for evaluation. If no
  decienciesareidentiedaWarrantyValidationLetterwillbeissuedthatprovidesallwarrantydates
  andcoverage.Ifinstallationorstart-updecienciesarepresent,thesemustbecorrectedand
communicated to Desert Aire in order to activate warranty.
3. This warranty shall not apply to any part that has been tampered with, or has been subject to
misuse, negligence or accident. A warranty can be obtained for altered equipment but only with
written consent from Desert Aire.
 4. Thefollowingpartsandcomponentsareexcludedfromthewarranty:belts,lters,driers,fusesand
refrigerant.
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5. Refrigerant coils or other components that corrode due to improperly balanced air chemistry or
corrosive air quality will not be warranted.
6. All replacements or repairs will be FOB Germantown, WI.
7. This warranty shall be null and void if defects or damages result from unauthorized opening of the
refrigerant circuit, tampering with factory set controls, or operating outside the original design conditions.
8. Desert Aire shall not be liable for labor costs incurred in diagnosing the problem, or the removal
or replacement of the part or parts being repaired.
9. Desert Aire must preauthorize all warranty coverage described herein.
Extended Warranty:
Your Desert Aire unit may have extended warrantees beyond this Standard Limited Warranty document.
Extended warrantees are only available at the time of the purchase of the original equipment. These extended
warrantees are covered under a separate document and their terms and conditions are separate from this
document. It is mentioned in this document for informational purposes only. Any Extended Warranties will be
identiedontheWarrantyValidationletter.
Any and all incidental or consequential damages are expressly excluded from this warranty. Some states do not allow
the exclusion of incidental or consequential damages for personal injury, so the above limitations may not apply to you
for certain damages. This warranty gives you specic legal rights, and you may also have other rights, which vary
from state to state. No person or representative is authorized to make any warranty or assume any liability not strictly
in accordance with the aforementioned.
Inquiries regarding warranty matters should be addressed to:
Desert Aire Corp c/o Service Manager
N120 W18485 Freistadt Road • Germantown, WI 53022
PH: [phone] • FAX: [phone] • E-MAIL: [email protected]
Additional copies of this manual can be purchased for a nominal fee from Desert Aire. Submit requests to the contact
information listed above.
Gas Heat Exchanger Ten (10)-Year Prorated Warranty Terms (For GA Series™ units with gas heat only)
Desert Aire offers an extended prorated eight (8)-year warranty for gas heat exchanger. All other heater components
are covered under the initial 2 year warranty.
2 Years Parts Only from date of shipment. Prorated from years 3-9 as follows:
Year 3: Desert Aire warrants 70% of replacement price
Year 4: Desert Aire warrants 60% of replacement price
Year 5: Desert Aire warrants 50% of replacement price
Year 6: Desert Aire warrants 40% of replacement price
Year 7: Desert Aire warrants 30% of replacement price
Year 8: Desert Aire warrants 20% of replacement price
Year 9: Desert Aire warrants 10% of replacement price
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For Units w/Gas Heat:
For Your Safety Read Before Operating
WARNING: If you do not follow these instructions exactly a fire or explosion
may result causing property damage, personal injury or loss of life.
A. This appliance does not have a pilot. It is equipped with an ignition device that automatically
lights the burner. Do not try to light the burner by hand.
B. BEFORE OPERATING smell all around the appliance area for gas. Be sure to smell next to the
floor because some gas is heavier than air and will settle on the floor.
WHAT TO DO IF YOU SMELL GAS
• Do not try to light any appliance.
• Do not touch any electric switch; do not use any phone in your building. Immediately call
your gas supplier from a neighbor’s phone. Follow the gas supplier’s instructions.
• If you cannot reach your gas supplier, call the fire department.
C. Use only your hand to push in or turn the gas control knob. Never use tools. If the knob will
not push in or turn by hand, don't try to repair it, call a qualified service technician.
Force or attempted repair may result in a fire or explosion.
D. Do not use this appliance if any part has been under water. Immediately call a qualified service
technician to inspect the appliance and to replace any part of the control system and any gas
control that has been under water.
OPERATING INSTRUCTIONS
1. STOP! Read the safety information above on this label.
2. Set the thermostat to lowest setting.
3. Turn off all electric power to the appliance.
4. This appliance is equipped with an ignition device that automatically lights the burner.
Do not try to light the burner by hand.
5. Turn gas control knob clockwise to "OFF" position.
6. Wait five (5) minutes to clear out any gas. Then smell for gas, including near the floor.
If you smell gas, STOP! Follow "B" in the safety information above on this label. If you don't
smell gas, go to next step.
7. Turn gas control knob counterclockwise to "ON" position.
8. Turn on all electric power to unit.
9. Set thermostat to desired setting.
10. If appliance will not operate, follow the instructions “To Turn Off Gas To Appliance” and call
your service technician or gas supplier.
TO TURN OFF GAS TO APPLIANCE
1. Set thermostat to lowest setting.
2. Turn off all electric power to the appliance if service is to be performed.
3. Turn gas control knob clockwise to "OFF" position.
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Safety Labels are used throughout this manual. They comply with the ANSI Z535.4 Standard.
Pleasebefamiliarwiththefollowinglabelsandtheirdenitions.
This is the safety alert symbol. It is used to alert you to potential
personal injury hazards. Obey all safety messages that follow this
symbol to avoid possible death or injury.
Indicates an imminently hazardous situation which, if not
avoided, will result in death or serious injury.
Indicates a potentially hazardous situation which, if not
avoided, could result in death or serious injury.
Indicates a potentially hazardous situation which, if not
avoided, could result in minor or moderate injury.
Caution used without the safety alert symbol indicates a
potentially hazardous situation which, if not avoided, could
result in property damage.
Product Warning for the State of California
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TABLE OF CONTENTS
1 Introduction ................................................................................................................................. 9
1.1 Inspection ...................................................................................................................... 9
1.2 Freight Damage Claims ................................................................................................. 9
1.3 Rigging .......................................................................................................................... 9
1.3.1 Rigging the Unit ................................................................................................. 9
2 Installation
.................................................................................................................................. 13
2.1 Location of Climate Control System .............................................................................. 13
2.2 Duct Installation ............................................................................................................ 14
2.3 Condensate Drain Piping .............................................................................................. 14
2.4 Water Piping Installation (Water-Cooled Systems Only) ............................................... 16
2.5 Remote Condenser Installation (Air-Cooled Systems Only) .......................................... 17
2.6 High Voltage Wiring
...................................................................................................... 18
2.6.1 High Voltage Connections ................................................................................. 18
2.6.2 Wire and Fuse Sizing ........................................................................................ 19
2.7 Controls and Sensors
................................................................................................... 19
2.7.1 Supply Air Duct-Mount Temperature Sensor ..................................................... 20
2.7.2 Zone Sensor(s) .................................................................................................. 20
2.7.3 Photo Sensor ...................................................................................................... 21
2.7.4 Remote Display Terminal (Optional) .................................................................... 22
2.7.5 CO2Enrichment (Optional) ................................................................................. 23
2.8 Auxiliary Heating Control Wiring
................................................................................... 25
2.8.1 Auxiliary Heating - Dry Contact Closure .......................................................... 25
2.8.2 Auxiliary Heating - Proportional Signal ............................................................ 25
2.9 Gas Heater (Optional) ................................................................................................... 25
2.9.1 Gas Heater Installation ................................................................................... 26
2.9.2 Gas Piping ...................................................................................................... 27
2.9.3 Gas Heater Location ........................................................................................ 32
2.10 Electric Heater (Optional) For GA Series™ Products ..................................................... 35
2.11 Auxiliary Heat Coil Piping (Optional) ............................................................................. 35
2.12 Smoke Alarm Interlock .................................................................................................. 36
2.13 Cover Plates (if applicable) ........................................................................................... 36
2.14 Roof Curb w/ Wood Nailer (if applicable) ...................................................................... 37
3. Start-Up Procedures ................................................................................................................... 39
3.1 Preliminary Inspection ................................................................................................... 39
3.2 Gas Heater Start-Up (Optional) ..................................................................................... 41
3.2.1 Burner Adjustment .......................................................................................... 42
 3.3 AirowBalancing........................................................................................................... 43
3.3.1 Blower Adjustment Procedure ........................................................................ 43
   3.3.1.1UnitswithVariableAirow(ECFanorVFDEquipped)..................... 43
3.3.1.2 Single Speed Units (Units without a VFD or EC Fan) ........................ 44
3.4 Refrigeration Testing ...................................................................................................... 45
  3.4.1 Dehumidication/CoolingMode.................................................................... 46
3.5 General Testing
............................................................................................................ 46
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3.6 Routine Maintenance Schedule ................................................................................... 47
3.6.1 Service Every Month ........................................................................................ 47
3.6.2 Service Every Six Months ..................................................................
.............. 47
3.6.3 Service Every Year .............................................................
.............................. 48
3.6.3.1 Gas Heater (Optional)
........................ ............................................... 48
4 Troubleshooting
........................................................................................................ .................. 51
4.1 The Blower Does Not Run ............................................................................................. 51
4.2 The Compressor(s) Do Not Run .................................................................................... 51
4.3 High Pressure Alarms / Readings Above High Pressure Trip Setpoint ...
....................... 52
4.4 Low Pressure Alarms (Below 97 PSIG) Evaporator Coil Icing ................
....................... 52
5 Appendix
...................................................................... ................................................................ 53
5.1 Compressor Failure ................
........................................................................................ 53
5.1.1 Compressor Replacement ............................................................................... 53
5.2 Recommended Duct Design
.......................................................................................... 57
5.3 Recommended Controller Settings
................................................................................ 58
5.4 GrowAire®Sequence of Operation
................................................................................ 58
5.4.1 Basic Sequence
.............................................................................................. 58
5.4.2 Blower Operation ............................................................................................. 59
  5.4.3 DehumidicationOperation............................................................................... 59
5.4.4 Cooling Operation ................................................................
............................ 60
5.4.5 Heating Operation ........................................................................
.................. . 60
5.4.6 Suction Pressure Operation ................................................
............................. 60
5.5 Component Replacement, Charge, Evacuation, & Leak Instructions ..........
.................. 61
5.6 System Rating Plate ...................................................................................................... 66
5.7 Start-Up Supervision Supplemental Information
........................................................... 67
5.8 System Start-Up Report
.................................................................. .............................. 67
Start-Up Request Form ................................................................................................ 68
Start-Up Report
............................................................................. ................................ 69
Compressor Replacement Form
................................................... ................................ 73

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1. Introduction
Desert Aire climate control units are designed to provide years of reliable service when installed
properly. Read these instructions carefully before you install the unit.
1.1. Inspection
Desert Aire inspects and tests each climate control unit before it leaves the factory so that you
receive a quality piece of equipment. Unfortunately, equipment may become damaged in
transit. Inspect the unit carefully before signing the receiving papers. Check for both visible and
concealed damage. Remove crating and inspect the exterior cabinet for damage. Dented
 panels,brokencratingoranyuidleakingfromtheunitshouldbedocumentedupondelivery.
1.2. Freight Damage Claims
If the unit has been damaged, document the extent of the damage. Take pictures if possible.
 Next,obtainaclaimformfromthecarrier.Promptlylloutandreturntheform.
 Carriersmaydenyclaimsthatyouhavenotlledoutwithinaweekofdelivery.NotifyDesertAire
of any damage. Damaged units must have signed documents at the time of delivery to be eligible
for a freight claim.
1.3. Rigging
1. Failure to observe rigging instructions may lead to equipment damage, personal
injury, or death.
2. Lifting method and procedure must comply with all local and national codes and
regulations.
3. The use of safety slings in addition to lifting lugs is required.
4. Do not lift the dehumidifier in high winds or above people.
 DesertAiredehumidiersaresolidlybuiltandcanbeveryheavy.Avoidpersonalinjuryand
damaging the equipment by planning the installation carefully. Use moving equipment whenever
possible.
1.3.1. Rigging the Unit
Depending upon the unit type, various rigging methods are used to best lift the
equipment. Please reference the applicable sections below:
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  • AllProducts(GV,GAandGS)
Personnel should avoid stepping on the top of the unit. Desert Aire
units are not designed to support the weight of a person on all
portions of the roof. Damage incurred through caved or distorted top panels
will not be covered under warranty. If you must walk on the top panels,
carefully walk on the edges where structural integrity is greatest.
  • GVSeries™Products
- 4-15 Ton
Move the unit to the desired installation location with the unit on the
wood skid. To remove unit from skid, position fork lift parallel to the
boards on the top of the skid. Carefully slide forks between the unit
and cross braces to pick the unit off the skid. The unit will have to be
carefully removed from the fork lift and placed into the desired
location using hand truck equipment dollies or pipe rollers. Use
caution to not damage the unit with the fork lift or tip the unit over
ensuring it is kept as level as possible.
- 20-30 Ton
The base is equipped with a built-in 12 gauge skid. Use a fork lift to
move the unit into place. Use caution to not damage the unit with the
fork lift or tip the unit over ensuring it is kept as level as possible. In all
cases, use appropriate safety practices while lifting the unit. Forklift
tie-down clamps, straps, and other restraints where applicable should
be used to prevent tipping of the load.
• GA Series™ and GS Series™ Products
GA Series™ and GS Series™ units are equipped with four or more lifting
points. Use spreader bars and safety straps when you rig the equipment.
- Utilize all of the lifting lugs provided when hoisting the unit.
- Test-lift the unit to verify that it is properly balanced.
- Refer to diagram below for additional lifting instructions.
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Figure 1 - Typical Rigging for a Large Unit
1. Do not tip the unit on its side.
2. Avoid dropping the unit down stairways or subjecting it to severe mechanical shock.
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2 Installation
 Manualappliestostandardunitcongurationsonly.
2.1 Location of Climate Control System
 DesertAireGSSeries™climatecontrolunitsareconguredtoallowsingle-sideaccess.This
means you can make your service connections and perform routine maintenance when you must
install one side of the unit close to a wall or other restriction. The “service side” is determined
 whentheorderisplacedatthefactoryandcannotbechangedintheeld.Itisrecommended
that clearance be provided on all sides to allow for ease of serviceability in the event large
components require replacement. GA Series™ and GV Series™ units may require service
access from multiple sides. Refer to the general arrangement drawing for further details.
Allow a minimum of 36 inches of clearance around the service side of the unit for piping,
electrical connections, and service access. The non-access side of the unit should contain 12
inches of clearance for large component removal. For packaged units, ensure a minimum of one
 unitwidthofclearanceismaintainedtoallowforproperairowthroughthecondensingsection.
If three or more walls surround the unit consult the factory for proper unit location to allow for
 adequateairowthroughthecondensersection.
Install the unit on a sturdy, level mounting base or platform that will prevent vibration and sound
transmission. Never install the unit on a wooden or metal platform without consulting
the design engineer for spring isolation requirements and sound control materials. Do not install
 theunitnearoccupiedroomssuchasofcesorguestrooms.Donotattempttoconserve
installation space by fabricating restrictive ductwork with abrupt bends. You may reduce the
 operatingefciencyandthemoistureremovalcapacityoftheunit.Seesection5.2for
detailed duct installation instructions.
Units located in unconditioned spaces may form condensation on the exterior of the cabinet.
Precautions should be taken for indoor units located within unconditioned spaces to prevent
damage resulting from condensation.
Do not install an indoor-rated unit in an outdoor or a wet environment.
If you must install a system outside you must use an outdoor-rated unit. Desert Aire seals and
 weatherproofsoutdoorunitstohelppreventwaterinltration.Youcandeterminewhetheryour
unit is outdoor-rated by inspecting the unit rating plate.
See section 5.6 for details.
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2.2 Duct Installation
Duct design and installation should conform to the latest ASHRAE and SMACNA low velocity
duct standards. See section 5.2 for details. Undersized, restrictive ductwork with abrupt turns
 ortransitions,candecreasetheefciencyandthemoistureremovalcapacityofyourunit.Size
 theductworkforanacceptableairpressuredropattheairowvolumeofyourunit.Use
 neopreneexconnectorswhenyouattachductworktotheunittopreventtransmissionof
excess vibration and noise.
Select the grilles, registers and diffusers for low static pressure loss, required throw distance,
 andthespeciedCFMrating.Youcanndthisinformationinmostgrillemanufacturer’s
catalogs. If you are installing the grilles in a corrosive environment, choose components made
from anodized aluminum.
 Ifyoumustinstallductworkinanunconditionedarea,useberglassductwrapwithvapor
barrier facing. You must install the outdoor air intake away from all sources of airborne
contamination such as exhaust fans or plumbing vents. You can use galvanized sheet metal
ducts for most applications. However, you should use aluminum or stainless steel ducts for
extreme applications such as chemical-laden environments.
2.3 Condensate Drain Piping
Condensate drain lines installed in an unconditioned space must be heat taped to
prevent freezing. Check the heat tape yearly before winter operation.
The condensate drain connection may be on the side or the bottom of the unit, depending on
the size and style of the cabinet used. Use concrete blocks or steel dunnage to raise the unit
 highenoughabovetheoortoprovideclearancefortheeld-suppliedcondensatedraintrap.
Note: Units with gas heating option may have condensate form inside the furnace heat
exchanger since it is located downstream from the cooling coil. On indoor units, you must also
 connecttheheater’sdrainline(ifpresent)toyoureld-installedcondensatedrainageplumbing.
Note: While the supply blower runs, the drain pan area inside the unit operates at a negative
pressure. Your unit requires a p-trap in the condensate drain pipe to prevent condensate from
being drawn into the cabinet.
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Min. 12”
P-Trap (By Others)
Vibration
Isolator
Base /Support
(By Others)
1/4” Slope
Per Foot
Figure 2 - Condensate Piping (Bottom-Mounted Drain Shown)
4”
4”
Figure 3 - Sectional View of Condensate Trap Requirements
Trap the condensate as shown in Figure 3. The P-trap dimensions in Figure 3 are sized for a
 maximumreturnairstaticof2.0”ofwater.Ifyourreturnairstaticexceedsthisspecication,
consult Desert Aire for help in resizing the P-trap.
You may also need to install a cleanout tee or plug near the trap. Note that the drain opening
in the drain pan is off-center to simplify its cleaning and servicing. Once you have designed
and installed the trap, follow this sequence:
1. Connect the trap to a main drain line with 1/4” of downward pitch per linear foot of run.
 2. Supportthedrainpipeeveryvefeettopreventsagging.
3. After you install the drain piping, prime the trap by pouring water into the drain pan of
the unit.
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2.4 Water Piping Installation (Water Cooled Systems Only)
As an option, the unit may be equipped with a tower water condenser. Use industry standard
piping practices when connecting to such a unit. Connections are copper stubs. Refer to
 submittaldocumentationforspecicsizepermodel.
Water Quality and General System Design
 A60meshornerstrainermustbeinstalledinthewaterinletline.Flusheld-installedpiping
 thoroughlybeforeyouputtheunitintoservice.Apipingsystemnotproperlyushedor 
 lteredwillcausethebrazed-plateheatexchangertoloseefciencyorfailprematurelydueto
clogging and/or fouling.
To prevent premature failure of the heat exchanger, maintain the water at a pH of 7.4, but
never below 6.0. Do not use water with high concentration of sulfur, chlorine, or sodium
chloride.
A dedicated circulating pump must be used unless the main pump can develop enough head
to overcome the combined resistance of the water condenser and the piping connected to it.
 SeespecicFlowRatesectionfortherequiredwaterowrateandheadforyourapplication.
Install an air eliminator at any high point in the water piping. Air trapped in the water circuit
of the unit can lead to elevated operating pressures, unexpected service calls, and decreased
equipment life.
If the water system is connected to a variable frequency drive or to water loops with multiple
 units,owregulatingvalvesshouldbeinstalledtoensureowrateismaintained.
Do not exceed these guidelines as excessive flow rates will erode the condenser and piping.
 GSSeries™andGVSeries™ProductsFlowRate
 Theowrateandantifreezeconcentration(ifused)willdependontheapplication.Pleaserefer
 toFigure4and5fortherequiredowrateandtemperaturelimitsforthegivenapplicationand
unit type. If the application deviates from these conditions, please contact Desert Aire Service
at 262-946-7400 for further review.
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17
Unit Size (Nom. Tons)
2
3
4
5
8
10
15
20
25
30
36
40
46
50
56
60
Fluid Flow Rate (GPM)
9
15
15
19
20
28
45
57
70
87
99
123
135
143
156
172
Fluid Pressure Drop (psig)
0.9
1.3
1.7
2.6
2.3
2.8
2.7
2.7
2.7
2.8
3.1
2.8
2.8
3.1
3.1
3.1
Note: Table allows for antifreeze concentrations up to 30% glycol and entering water temperatures between 35°F & 105°F
Figure 4 - Water Flow Rates
Glycol Percent
0
5
10
15
20 and up
Min. Entering Water Temperature (°F)
48
47
45
40
35
Figure 5 - Glycol Concentration Requirements
2.5 Remote Condenser Installation (Air-Cooled Systems Only)
Important: Refer to the separate Air Cooled Condensers Installation and Operation manual
for additional details on line design, traps, clamping, and other condenser installation
requirements.
GS Series™ and GV Series™ units installed with remote condensers may require additional oil
 andrefrigerantchargeatthetimeofeldinstallation.Refertothesubmittaldocumentationor
 labeladjacenttotheremotecondenserconnectionstoconrmthechargeandconnectiontubesizes.
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18
2.6 HighVoltageWiring
1. Disconnect power before servicing. The unit contains high voltage wiring and
moving parts which may cause serious injury or death.
2. Failure to properly wire the unit may create the possibility of shock and can lead to
premature system failure.
For any unit labeled Class 1, Group D, Division 2, all wiring must be in accordance to
Class 1, Group D, Division 2 requirements. Insure that all local, state, national and any
other applicable codes are adhered to when connecting any device to this equipment.
All electrical connections to units labeled Class 1, Group D, Division 2 must be done
with a conduit seal.
Electrical wiring must comply with all national, state, and local codes. Refer to the wiring
diagram located inside the electrical section for all wiring connections. To connect main power,
attach the supply wires to the three-pole power block mounted on the electrical panel. Test the
phasing by “bumping” the blower contactor. Verify that the blower rotates in the proper
direction. If it rotates the wrong direction, switch any two of the three wires at the power block.
 2.6.1 HighVoltageConnections
On single phase units the power supply must have 3 connections (2 power and 1
ground). On three phase units the power supply must have 4 connections (3 power
and 1 ground). Connect the power supply wires to the main power block located in
the upper section of the electrical compartment.
Ground Wire
L1
L2
L3
Main Power
Supply from
Disconnect Box
Main Power
Block in Unit
Factory Supplied
Wiring
Ground
Lug
Ground Wire
L1
L2
Main Power
Supply from
Disconnect Box
Main Power
Block in Unit
Factory Supplied
Wiring
Ground
Lug
Figure 6 - Single-Phase and Three-Phase System Power Connection
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19
2.6.2 Wire and Fuse Sizing
  Theeld-installedpowersupplywiresandovercurrentdevicesmustbesizedto
handle the minimum amperage of the unit without exceeding the maximum
fuse size rating. Both the minimum amperage and the maximum fuse size are printed
on the unit rating plate.
2.7 Controls and Sensors
For any with Intrinsically Safe circuits, wiring to these devices must be done only to
Intrinsically Safe terminal strip. Refer to the wiring schematic for details of these devices
and wiring parameters. The length, capacitance, resistance, and inductance of the cable
used to connect the field wiring of the Intrinsically Safe circuit shall not overload the rating
of the Intrinsically Safe barrier.
The standard Desert Aire Grow Room environmental control systems are controlled by a
microprocessor controller. This controller is designed for precise monitoring and control of air
temperature and relative humidity (RH) within a conditioned environment. A separate controls
manual has been provided. Refer to this separate manual for controller and sensor
 specications,operation,andoptions. 
Sensors must be installed and wired prior to unit startup. Please refer to the following for
general sensor information in addition to the separate controller manual. A general example of
 sensorlocationandwiringhasbeenprovidedbelowingure7.
UNIT 1 UNIT 2 UNIT 3
w/AIREGUARD
CNTRL BOX
T/RH T/RH T/RH (OPTIONAL)
4-WIRE 4-WIRE
4-WIRE
PHOTOCELL (OPTIONAL)PHOTOCELL
PHOTOCELL
TO NETWORK
W/ INTERNET
CONNECTION
2-WIRE RJ12 CABLE (pLAN2-WIRE2-WIRE pLAN
3-WIRE 3-WIRE 3-WIRE
PGD
(OPTIONAL)
pLAN
T T T
ETHERNET CABLE
Figure 7 - Wiring and Location of Field Installed Sensors
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20
2.7.1 Supply Air Duct-Mount Temperature Sensor
The supply air duct-mount temperature sensor is used to control the supply air
temperature of the unit. This is an NTC temperature sensing bulb with 3 meters of
cable that is provided with a duct insertion sensor holder for mounting. This must
be mounted in a location that monitors only the supply air for the unit that it is
attached to. Install upstream of any duct tees that may connect two or more
systems together. If auxiliary heating is installed in the ducts and is to be controlled
by the Desert Aire enviromnental control system, the supply air sensor must be
installed downstream of the heater.
Figure 8 - Supply Air Duct Mounted Temperature Sensor
2.7.2 Zone Sensor(s)
A temperature and humidity zone sensor is supplied for each room. This will be
connected to the unit or one of the units servicing that room.
Some applications may desire redundant sensors. In this case, a room may have
multiple sensors located within it (maximum of one sensor for each unit).
Note that only one sensor is active at any time. To activate a different sensor, each
  unitneedstobereconguredtorespondtothealternatesensor.Ratherthan
installation of additional sensors immediately, it is recommended that these
  additionalsensorsareplacedinasecurelocationassparesandeldwiringis 
made conducive for quick and easy replacement should this become necessary.
See GrowAire®Users Manual for recommended practices for regular calibration.
If additional zone sensors are required, please consult the factory.
• Select a representative location for the sensor close to the plants where
you would like the temperature and humidity to be maintained. For
example, this may be at the leaves of the plant if that is the most critical
and represents the area that your desired settings should control to.
If redundant sensors are used, mount all sensors within this general
location. CAUTION: Do not mount the sensor in a location where false
readings may occur due to dead air regions, radiant heat gain from the
lighting, location too close to supply air diffusers, or thermal losses in winter.
Desert Aire - GS/GA/GV Manual