DIGITAL AIR™
LOAD RESISTORS
Operation Manual
©Copyright 2018
by Bird Technologies Inc.
Instruction Book Part Number 920-8579AS Rev. L
Thruline
®
is a Registered Trademark and
Digital Air™ is a Trademark of Bird Electronic Corporation
DigitalAirLoadResistors
i
Safety Precautions
Thefollowingaregeneralsafetyprecautionsthatarenotnecessarilyrelatedto
anyspecificpartorprocedure,anddonotnecessarilyappearelsewhereinthis
publication.Theseprecautionsmustbethoroughlyunderstoodandapplytoall
phasesofoperationandmaintenance.
WARNING
KeepAwayFromLiveCircuits
OperatingPersonnelmustatalltimesobservegeneralsafetyprecautions.Do
notreplacecomponentsormakeadjustmentstotheinsideofthetest
equipmentwiththehighvoltagesupplyturnedon.Toavoidcasualties,always
removepower.
WARNING
ShockHazard
DonotattempttoremovetheRF
transmissionlinewhileRFpowerispresent.
WARNING
DoNotServiceOrAdjustAlone
Undernocircumstancesshouldanypersonreachintoanenclosureforthe
purposeofserviceoradjustmentofequipmentexceptinthepresenceof
someonewhoiscapableofrenderingaid.
WARNING
SafetyEarthGround
Anuninterruptibleearthsafetyground
mustbesuppliedfromthemain
powersourcetotestinstruments.Groundingoneconductorofatwo
conductorpowercableisnotsufficientprotection.Seriousinjuryordeathcan
occurifthisgroundingisnotproperlysupplied.
WARNING
Resuscitation
Personnelworkingwithornearhighvoltagesshouldbefamiliarwithmodern
methods
ofresuscitation.
WARNING
RemovePower
Observegeneralsafetyprecautions.Donotopentheinstrumentwiththe
poweron.
SafetyPrecautions
ii
Safety Symbols
Thissymbolindicatesthatashockhazardexistsiftheprecautionsin
thein
structionmanualarenotfollowed.
Thecautionsymbolappearsontheequipmentindicatingthereis
importantinf
ormationintheinstructionmanualregardingthat
particulararea.
Thissymbolindicatesthattheunitradiatesheatandshouldnotbe
touchedwhi
lehot.
Note: Callsattentiontosupplementalinformation.
Warning Statements
Thefollowingsafetywarningsappearinthetextwherethereisdangerto
operatingandmaintenancepersonnel,andarerepeatedhereforemphasis.
Seepages8and.22.
Seepages12and13,
Seepage14.
WARNING
Wa
rningnotescallattentiontoaprocedure,whichifnotcorrectlyperformed,
couldresultinpersonalinjury.
CAUTION
Cautionnotescallattentiontoaprocedure,whichifnotcorrectlyperformed,
couldresultindamagetotheinstrument.
WARNING
TurnoffACpowerandRFpowerbeforeremovingorreplacingtheaccess
panel;thepot
entialforelectricalshockexists.
WARNING
Ensurethepoweristurnedoffwhenattachingpowercableorwire.
WARNING
NeverattempttoconnectordisconnectanRFcableorlinewhilepowerison
attheRFpowersource.RadiatedRFenergyisapotentialhealthhazard.
DigitalAirLoadResistors
iii
Seepage16.
Seepages19.
Seepage22.
Seepage22.
Seepage22.
Caution Statements
Thefollowingequipmentcautionsappearinthetextwhenevertheequipmentis
indangerofdamageandarerepeatedhereforemphasis.
Seepage7.
Seepage9.
WARNING
Exhaustedairmayexceed95°C(203°F).
WARNING
DisconnectthisunitfromtheRFpowersourcesandtheaclinebeforeany
disassembly.Thepotentialforelectricalshockexists.
WARNING
Improperwiringcouldresultinelectricshockanddeath.
WARNING
Highheatpresentinsideunit!Letcoolforatleast10minutesbeforeservicing
orsevereburnscouldresult.
WARNING
Maintenancebyotherthantrainedservicepersonnelcouldresultinelectric
shock.
CAUTION
Donotblockairflow.Airisforcedintothehousingviafansonallfoursides
andexhauststhroughagrilleonthelowerrearoftheunit.Blockingairinputs
orexhaustcould
causeunitfailure.
CAUTION
Connectinterlockbefor eRFoperation.
SafetyPrecautions
iv
Seepage12.
Seepage16
CAUTION
.
Seepag
e17.
Seepage17.
Seepage17.
Seepage22.
Seepage22.
CAUTION
Che
ckthelocalelectricalcodeforproperAChookuppriortooperationofthe
unit.Makesuretheneutralorreturnhookupisonlyusedforthatpurpose.
CAUTION
DonotoperatewithoutACpowertotheload.
Dono
toperateabovetheratedcapacity.See “Specifications”onpage25.if
unsureoftheratingthemodelload.Theunitwillhandleasmallpercentage
ofoverloadforbriefperiodsoftimeduringtransmittertuningoradjustment.
However,longperiodsofoverload(>10%ofratedpowerfor>30min)ma
y
damagetheunitorcausethetemperatureinterlocktoopen.
CAUTION
ApplyingmorethantheratedaverageRFpowertotheloadmaydamagethe
loadresistor.
CAUTION
DonotdisconnectAClinepowerbeforeturningoffRFpowertotheload.
ApplicationoffullRFpowertotheloadwhi
lethefansarenotrunningwill
causetheloadtooverheatanddestroytheresistorelements.
CAUTION
Improperwiringcoulddisableload.
CAUTION
Donotdisablefans.Appl icationoffullRFpowertotheloadwhiletheair
circulationisoffwillcausetheloadtooverheatanddestroytheresistor
elemen
ts.
DigitalAirLoadResistors
v
Seepage22.
Seepage22.
CAUTION
Allreplacementwiringmustbe18AWG,withinsulationratedto400°F
(205°
C).Useofotherwiringcouldresultinunitdamage.
CAUTION
Thiscircuitdiagramforusebytrainedservicepersonnelonly.Improperuse
coulddisableload.
SafetyPrecautions
vi
Safety Statements
USAGE
ANY USE OF THIS INSTRUMENT IN A MANNER NOT SPECIFIED BY
THE MANUFACTURER MAY IMPAIR THE INSTRUMENT’S SAFETY
PROTECTION.
USO
EL USO DE ESTE INSTRUMENTO DE MANERA NO ESPECIFICADA
POR EL FABRICANTE, PUEDE ANULAR LA PROTECCIÓN DE
SEGURIDAD DEL INSTRUMENTO.
BENUTZUNG
WIRD DAS GERÄT AUF ANDERE WEISE VERWENDET ALS VOM
HERSTELLER BESCHRIEBEN, KANN DIE GERÄTESICHERHEIT
BEEINTRÄCHTIGT WERDEN.
UTILISATION
TOUTE UTILISATION DE CET INSTRUMENT QUI N’EST PAS
EXPLICITEMENT PRÉVUE PAR LE FABRICANT PEUT
ENDOMMAGER LE DISPOSITIF DE PROTECTION DE
L’INSTRUMENT.
IMPIEGO
QUALORA QUESTO STRUMENTO VENISSE UTILIZZATO IN MODO
DIVERSO DA COME SPECIFICATO DAL PRODUTTORE LA
PROZIONE DI SICUREZZA POTREBBE VENIRNE COMPROMESSA.
DigitalAirLoadResistors
vii
SERVICE
SERVICING INSTRUCTIONS ARE FOR USE BY SERVICE - TRAINED
PERSONNEL ONLY. TO AVOID DANGEROUS ELECTRIC SHOCK, DO
NOT PERFORM ANY SERVICING UNLESS QUALIFIED TO DO SO.
SERVICIO
LAS INSTRUCCIONES DE SERVICIO SON PARA USO EXCLUSIVO
DEL PERSONAL DE SERVICIO CAPACITADO. PARA EVITAR EL
PELIGRO DE DESCARGAS ELÉCTRICAS, NO REALICE NINGÚN
SERVICIO A MENOS QUE ESTÉ CAPACITADO PARA HACERIO.
WARTUNG
ANWEISUNGEN FÜR DIE WARTUNG DES GERÄTES GELTEN NUR
FÜR GESCHULTES FACHPERSONAL. ZUR VERMEIDUNG
GEFÄHRLICHE, ELEKTRISCHE SCHOCKS, SIND
WARTUNGSARBEITEN AUSSCHLIEßLICH VON QUALIFIZIERTEM
SERVICEPERSONAL DURCHZUFÜHREN.
ENTRENTIEN
L’EMPLOI DES INSTRUCTIONS D’ENTRETIEN DOIT ÊTRE RÉSERVÉ
AU PERSONNEL FORMÉ AUX OPÉRATIONS D’ENTRETIEN. POUR
PRÉVENIR UN CHOC ÉLECTRIQUE DANGEREUX, NE PAS
EFFECTUER D’ENTRETIEN SI L’ON N’A PAS ÉTÉ QUALIFIÉ POUR CE
FAIRE.
ASSISTENZA TECNICA
LE ISTRUZIONI RELATIVE ALL’ASSISTENZA SONO PREVISTE
ESCLUSIVAMENTE PER IL PERSONALE OPPORTUNAMENTE
ADDESTRATO. PER EVITARE PERICOLOSE SCOSSE ELETTRICHE
NON EFFETTUARRE ALCUNA RIPARAZIONE A MENO CHE
QUALIFICATI A FARLA.
SafetyPrecautions
viii
CONNECT INTERLOCK TO TRANSMITTER BEFORE OPERATING.
BRANCHER LE VERROUILLAGE À L’ÉMETTEUR AVANT EMPLOI.
CONECTE EL INTERBLOQUEO AL TRANSMISOR ANTES DE LA
OPERACION.
VOR INBETRIEBNAHME VERRIEGELUNG AM SENDER
ANSCHLIESSEN.
PRIMA DI METTERE IN FUNZIONE L’APPARECCHIO, COLLEGARE
IL DISPOSITIVO DI BLOCCO AL TRASMETTITORE.
DigitalAirLoadResistors
ix
About This Manual
ThisinstructionbookcoversBirdDigitalAirLoadResistorModels:
Changes to this Manual
Wehavemadeeveryefforttoensurethismanualisaccurate.Ifanyerrorsare
discovered,orifthereareanysuggestionsforimprovingthismanual,please
sendcommentstoourSolon,Ohiofactory.Thismanualmaybeperiodically
updated.Wheninquiringaboutupdatestothismanualrefertothepart
number
andrevisiononthetitlepage.
ThemostrecentrevisionofthismanualcanbefoundonBird’swebsite:
http://www.birdrf.com.
DA5F15 DA5U15 DA5UR15
DA5F30 DA5U30 DA5UR30
DA10F15 DA10U15 DA10UR15
DA10F30 DA10U30 DA10UR30
DA15F15 DA15U15 DA15UR15
DA15F30 DA15U30 DA15UR30
DA25F15 DA25U15
DA25F30 DA25U30
DA25-4U15
DA25-4U30
DA40F15 DA40-5U15
DA40F30 DA40-5U30
DA10V1F15 DA10V1U15 DA10V1UR15
DA10V1F30 DA10V1U30 DA10V1UR30
DA10V3F15 DA10V3U15 DA10V3UR15
DA10V3F30 DA10V3U30 DA10V3UR30
DA25V3F15 DA25V3U15 DA25V3UR15
DA25V3F30 DA25V3U30 DA25V3UR30
DA25V4U15
DA25V4U30
AboutThisManual
x
Chapter Layout
Introduction —
DescribesthefeaturesoftheDigitalAirLoad,listsequipment
suppliedandoptionalequipment,andprovidespowerupinstructions.
Installation — Describeshowtosetuptheloads,reviewsfeaturesofthe
DigitalAirLoadthathelpininitialuse,andprovidespowerupinstructions.
Operating Instructions — Describesbasicuseandvariousmodesof
operation.
Maintenance — Listsroutinemaintenancetasksaswellastroubleshootingfor
commonproblems.
Theory of Operation — DescribeshowtheDigitalAirloadswork.
Specifications — Listsspecificationsandpartsinformation.
xi
Table of Contents
Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i
SafetySymbols...... ................ ................ ..........
.. ii
WarningStatements............................ ................. ii
Caution
Statements................ ................ ..............iii
SafetyStatements..
.............................. ...............vi
About This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
ChangestothisManual.
............... ................ ...........ix
ChapterLayout.......
....................................... x
Chapter 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Description ..........
........................................... 2
Chapter 2 Theory of Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
RFSectionDescription...
........................................ 4
HeatRemoval........
........................................ 4
FanActivation........
.............................. ......... 4
ThermalInterlock.........
................................... 5
LinePowerInterlock............
.............................. 5
Chapter 3 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
UnpackingandInspection................
......................... 6
UnitPlacement..... ................ ..
............... ........... 6
DuctingPlacement... .. .................
............... ......... 7
AccessPanel..................... ...
............................ 8
InterlockConnection ....................
......................... 9
SixTerminalInterlockwithPowerRelay ....... ............
....... 9
SixTerminalInterlockwithout PowerRelay ...................... 11
TwoTerminalInterlock ............
........................... 11
ACPowerHookup....................
.......................... 12
ACPowerCable.....................
........................ 12
ACPowerCableStrainRelief.................. ...
................ 13
ACHardWiring..................... ..........
................. 13
EarthGroundingLug..............................
........... 13
ConnectingRFPower....................................
....... 14
TableofContents
xii
SwivelFlangedCoupling............ .......................... 14
UnflangedCoupling ....
...................................... 14
41/16”Coupling .........
................................... 15
Chapter 4 Operating Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
AutomaticMode............
................................... 16
ManualMode.......... ...
............... ................ ...... 16
LoadOperation...........
............... ................ ... 16
InterlockOperation ..............
............... ............. 17
ManualShutDown...................
............... ........ 17
AutomaticShutDown . .......................
................ 18
MeasurementandMonitoringofRFPower......................... 18
Chapter 5 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Troubleshooting.
............................................... 19
CleaningandInspection
................................... ...... 20
PreparationforStorageorShipment....
........................... 20
Storage ................. .....
.............................. 20
Shipment...................
............................... 20
CustomerService..... ............
.............................. 21
CircuitDiagram..................
.............................. 22
Specifications ...................
............................... 25
Appendix 1 Difference Data Sheet 29
Specificationsfor12.5kWDigitalAirLoad...........
............... 29
Limited Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
1
Chapter 1 Introduction
Figure 1 Digital Air Outline Drawing
Series Dim. A Dim. B Dim. C Dim. D Dim. E Dim. F Dim. G
DA10V 23.5”
(597mm)
23.5”
(597mm)
49.5”
(1257mm)
59”
(1499mm)
N/A
Forklift openings are not provided for these models.
N/A
N/A
DA25V 27.0”
(686mm)
27.0
(686mm)
50.8”
(1289mm)
61.0”
(1549mm)
N/A
N/A
N/A
DA5 17.0”
(432mm)
17.0”
(432mm)
55.5”
(1410mm)
64.0”
(1626mm)
N/A
N/A
N/A
DA10 19.5”
(495mm)
19.5”
(495mm)
60.0”
(1524mm)
68.5”
(1740mm)
N/A
N/A
N/A
DA15 25.0”
(635mm)
25.0”
(635mm)
68.0”
(1727mm)
76.5”
(1943
mm)
24.5”
(622mm)
6.0”
(152mm)
2.0”
(50.8mm)
DA25 27.0”
(686mm)
27.0
(686mm)
68.0”
(1727mm)
76.5”
(1943mm)
24.5”
(622mm)
6.0”
(152mm)
2.0”
(50.8mm)
DA40 27.5”
(701mm)
27.5
(701mm)
78.8”
(1999mm)
84.0”
(2134mm)
24.5”
(622mm)
6.0”
(152mm)
2.0”
(50.8mm)
Introduction
2
BirdDigitalAirLoadResistorsareaircooledandcapableofdissipatingRFline
powerupto40kW(dependingonthemodel).Virtuallymaintenancefreeand
simpletooperate,thisunitshouldprovideyearsoftroublefreeoperation.
Description
Theunitissupportedbyfourbumperfeet.TheRFinputconnectorislocatedon
thetopoftheunit. Fansonallfoursidesallowforforcedaircoolingofthe
resistors.Thetransmitterinterlockislocatedonthefrontpanel.Themodel
numberisprintedonalabelon
thelowerleftoftheunit.
Theunitisnot intendedforexposedoutdooruse,orinareasofcondensing
humidity.Ensureadequatespaceisavailableforaircirculation.
TheDigitalAirLoadResistorsareofferedinavarietyofformsdifferingintheir
powerratings,acinputpowerrequirements,frequencyranges,andconnector
types(see
Figure2onpage3
formodelnumbers).
Example‐AModelDA10F15isaUHF10kWloadwitha31/8”
flangedconnectorthatrequiresa115V50/60Hzpowersource.
DigitalAirLoadResistors
3
Figure 2 Digital Air Load Models
Model Number
Power Connector Freq. Range
Flanged,
115 VAC
Unflanged,
Flush
115 VAC
Unflanged,
Recessed
115 VAC
Flanged,
230 VAC
Unflanged,
Flush
230 VAC
Unflanged,
Recessed
230 VAC
5kW 31/8”EIA 470‐890MHz DA5F15 DA5U15 DA5UR15 DA5F30 DA5U30 DA5UR30
10kW 31/8”EIA 470‐890MHz DA10F15 DA10U15 DA10UR15 DA10F30 DA10U30 DA10UR30
15kW 31/8”EIA 470‐890MHz DA15F15 DA15U15 DA15UR15 DA15F30 DA15U30 DA15UR30
25kW 41/16”Myat 470‐890MHz DA25F15 DA25U15 DA25F30 DA25U30
25kW 41/2”IEC 470‐890MHz DA254U15 DA254U30
40kW 47/8 IEC 470‐890MHz DA405U15 DA405U30
40kW 61/8”EIA 470‐890MHz DA40F15
10kW 15/8 EIA DC‐240MHz DA10V1F15 DA10V1U30 DA10V1UR30
10kW 31/8”EIA DC‐240MHz DA10V3F15 DA10V3U30 DA10V3UR30
25kW 31/8”EIA DC‐240MHz DA25V3F15 DA25V3U30 DA25V3UR30
25kW 41/2”IEC DC‐240MHz
DA40F30
DA10V1U15 DA10V1UR15 DA10V1F30
DA10V3U15 DA10V3UR15 DA10V3F30
DA25V3U15 DA25V3UR15 DA25V3F30
DA25V4U15
DA25V4U30
4
Chapter 2 Theory of Operation
TheDigitalAirSeriesLoadsarehighpowered,aircooled,RFloadsusedfor
terminationofcoaxialtransmissionlines.TheRFenergy,whenconvertedinto
heat,istransmittedtothesurroundingareabyaforcedairsystem.
RF Section Description
TheRFsectionofaDigital Airloadisabroadb andtuneddevicecomposedof
tubularceramicresistors.Thesearecarefullypositionedtoproduceavery
uniformandalmostreflectionlesslineterminationoverthestatedfrequencies
oftheloadresistor.
Heat Removal
Wheninoperation,airisforcedintoallfoursidesoftheunitanddirectedover
theRFresistornetwork.Thehea t,developedintheresistorsfromdissipationof
RFenergy,iscarriedoffbytheflowofairovertheresistorssurface.Thehotairis
thenexhaustedthroughthe
grill einthebackofthe unit.
Fan Activation
ThefansontheDigitalAirloadsaretriggeredwithapairofnormallyopensnap
diskthermoswitches.ThetopswitchislocatedintheRFchamber,whilethe
bottomswitchislocatedintheairexitduct.Insteadystateoperation,afancycle
happensasfollows:
1. RisingairtemperatureintheRFchamberclosesthetopthermoswitch,
turningthefanson.
2. Thehotairisforcedintotheexitductbythefans,heatingthebottom
thermoswitchuntilitcloses.
3. AsthecoolairisblownintotheRFchamber,thetopswitchreopens.Since
thebottomswitchisclosed,thefansstayon.
4. WhenRFpowerisremoved,coolairreachestheexitduct,thebottom
switchopensandthefansturnoff.
Forpowerlevelssubstantiallybelowtheunitspowerrating,theairintheexit
ductmaynotheatupsufficientlytoclosethebottomswitch.Asaresult,the
fanscycleonandoffmoreoften.Forthesepowerlevels,itisrecommendedthat
theunitbeoperatedinmanualmode.
DigitalAirLoadResistors
5
Thermal Interlock
AllDigitalAir loadsaresupplied withapassive,normallyclosed,snapdisk
overtemperaturethermoswitch.Normallyclosed,theswitchopensabovethe
maximumsafeloadtemperature,turningoffthetransmitterpower.Because
dissipationoftheheatgeneratedbytheRFpowerdependsuponforcedair
cooling,ifairflowovertheresistor
arrayshouldstoporberestrictedthe
temperatureintheRFchambercanrisebeyondasafelimit.Theheatsensorwill
sensethechangeandactuatetheinterlockswitchtoturnoffthetransmitter.
Theinterlocksystemwillnotpermitreoperationofthetransmitteruntila
lower,safe
temperatureintheRFhousingisreached.
Line Power Interlock
DigitalAirloadsareequippedwithalinepowerfailureinterlocktoprovide
protectionagainstthelossofACpower.Theswitchisanormallyclosedrelay.
Theswitchopensifnolinepowerissuppliedtotheload,thebreakerontheload
istripped,orthepowerswitchon
theloadhasbeenturnedoff.Whenpoweris
restored,theinterlockwillreset.
6
Chapter 3 Installation
Thischapterprovidesinformationforonsiterequirements,unpacking,
inspection,andpreparingtheDigitalAirloadforuse.
Unpacking and Inspection
1. Carefullyinspectshippingcontainerforsignsofdamage.
Iftheshippingcontainerisdamaged,donotunpacktheunit.
ImmediatelynotifytheshippingcarrierandBirdTec hn o logies.
Iftheshippingcontainerisnotdamaged,unpacktheunit.Save
shippingmaterialsforrepackaging.
2. Inspectunitforvisualsignsofdamage.
Note: Ifthereisdamage,immediatelynotifytheshippingcarrier
andBirdTechnologies.
Unit Placement
Refertotheguidelinesinthissectionwhenplacingtheload.Handlesare
providedforallmodels.Forkliftopeningsareprovidedforlargermodels(see
Figure1
).Placementofthesemodelswithouttheuseofaforkliftisnot
recommended.
Donotuseinexposedoutdoorlocationsorinareasofcondensing
humidity.
Surroundingairmustbefreeofcontaminantsorparticlesthatcouldbe
drawnintotheairintakes.
DigitalAirloadshavenointermediatedielectricfluidorcoolant.No
waterhookupsarerequired.
DigitalAirloadsaredesignedtobeusedupright.
Note: Consultthefactoryforotherintendedorientations.
DigitalAirLoadResistors
7
Makesurethefollowingopenairrequirementsaremet:
Donotplacetheunitinasmallroomorclosetwithoutproper
ventilation.
Note: Inrestrictedareastheheatgivenoffbytheunitmay
increasetheambienttemperaturetoanunacceptablelevel.
Fanintakeopeningsshouldbeatleast4inchesfromwallsand
obstacles.
Note: Intakeairshouldnotexceedmaximumambienttempera
turesof45°C.
Theairexitductshouldbeatleast24inchesfromwallsandobstacles.
Donotplacetemperaturesensitiveequipmentneartheairexit,or
equipmentthatwillbeaffectedbyariseinambientairtemperature.
Note: Exitairtemperaturescanreachinexcessof95°Cdepending
onenvironmentalconditions.
Ducting Placement
Ductingtheunitexhaustisrecommendedforlargermodels.Mountingnutsare
providedontherearoftheunitforducting.Referto
Figure3
forthelocationof
themountingnuts.
Shouldanexternalductbedesired,makesurethefollowingrequirementsare
met:
Maximum0.2"H
2
Opressureriseat45°Cambient.
Allductsshouldbeatleasttheareaoftheairexitductontheunit.
Referto
Figure3
.
Ninetydegreeelbowsgoinguptotheceilingmay beginimmediatelyat
theloadexit.However,theyshouldhaveaminimum4inchradius,>15
inchespreferredandshouldtransitiontoalargerarea.
Ninetydegreeelbowsintothefloororatrightanglestothefloor
shouldstartaminimum5inchesfromtheloadexitandshouldhavea
minimum4inchradius,>15inchespreferredandshouldtransitiontoa
largerarea.
CAUTION
Donotblockairflow.Ai r isforcedintothehousingviafans
onallfoursidesandexhauststhroughagrilleonthelower
rearoftheunit.Blockingairinputsorexhaustcouldcause
unitfailure.
  • Page 1 1
  • Page 2 2
  • Page 3 3
  • Page 4 4
  • Page 5 5
  • Page 6 6
  • Page 7 7
  • Page 8 8
  • Page 9 9
  • Page 10 10
  • Page 11 11
  • Page 12 12
  • Page 13 13
  • Page 14 14
  • Page 15 15
  • Page 16 16
  • Page 17 17
  • Page 18 18
  • Page 19 19
  • Page 20 20
  • Page 21 21
  • Page 22 22
  • Page 23 23
  • Page 24 24
  • Page 25 25
  • Page 26 26
  • Page 27 27
  • Page 28 28
  • Page 29 29
  • Page 30 30
  • Page 31 31
  • Page 32 32
  • Page 33 33
  • Page 34 34
  • Page 35 35
  • Page 36 36
  • Page 37 37
  • Page 38 38
  • Page 39 39
  • Page 40 40
  • Page 41 41
  • Page 42 42
  • Page 43 43

Ask a question and I''ll find the answer in the document

Finding information in a document is now easier with AI