Comptus A70-SDL Series User manual

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INSTRUCTION MANUAL
for
WINDSPEED&DIRECTIONTRANSMITTER
MODELA70-SDL
DOCUMENT # 1278, Version D
A70-SDPL-N12 in NEMA 12 Box
A75-104Anemometer
A75-302WindVane
®

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Figure1
RecorderTracewithPredominate
NorthWind
540oScale 360oScale
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N E S W N E S N E S W N
Figure2
RecorderTracewith Predominate
SouthWind
540oScale 360oScale
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N E S W N E S N E S W N
INTRODUCTION
TheModelA70-SDLsystemprovides electrical
signalsproportionaltowindspeed anddirection.
Itacceptssignals fromanemometerswithAC
generators.
Thetranslatorwilloperatewithmostpotentiometric
typewind vanes.TheTranslatormaybe inone of
severalpackages. It may betrackmounted for
installationinanexistingenclosure. Itmaybe
suppliedin asteelNEMA 12JIC boxfor inside
deploymentor in asteel NEMA4box whena
weatherproof boxis required.
Thetransmitterconvertstheinformationfromthe
sensorsto 4-20ma signalsproportional towind
speedand direction. Twowinddirection ranges, 0-
360oand 0 - 540oare available. The 540orange is
recommendedif achartrecorderwillrecord wind
direction. Thisrangereduces transitionsfromzero
tofullscale whenthe windisfrom theNorth,
preventingtheentirechartfrombeing “painted.”
The360orangeisrecommendedwhen wind
directioniselectronicallyrecorded.The 360orange
providesthe bestresolutionand theleast cost. The
540orangeis bestwhen abrupttransitions fromzero
tofullscaleareundesirable.

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SPECIFICATIONS
OperatingPower:
Model A70-SDL1: 10 - 15 VDC
ModelA70-SDL6: 120 VAC, 50/60 Hz
ModelA70-SDL7: 230 VAC, 50/60 Hz
InputDevice:AnemometerwithACGenerator
ComptusA75-104
MaximumModel40
Qualimetrics Model2102
RMYoungWindMonitor
PotentiometricWindVane:
ComptusModelA75-302
QualimetricsModel2102
RMYoungWindMonitor
Output: Speed4-20ma ,Azimuth4-20 ma
Accuracy:Electronics +1%
Sensor:seeseparate specs.
A96-100PSurgeArrestor
Loop Resistance:
300 ohms Max.
TemperatureRange:
Electronics 0/60oC standard
-40/70oC extended
Sensors: see separate specs.
Dimensions: 3" WX 4.5" LX 11.5" D (N12)
5”WX 7” LX1” H (Trackmount)
Weight:Transmitter 8# (NEMA12 Steel Box)
Transmitter1/4#(TrackMount)
Connectors: Barrier Strip toAcceptAWG #14 or
smallerwire
Accessories: A96lightning arrestorrecommended
forsensor protection

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DESCRIPTION
TheA70-SDLSystemconsists ofaanemometer,
windvaneandtransmitter.
The A75-104 Anemometer is arugged three
cup device whoseaccuracy and reliability have
beenproven inwind tunnel and field testsover
manyyears. Theanemometer housingand rotor
are fabricated ofruggedLexan. Therotoris
supported by aberylliumcoppershaftriding in
Teflonbearings.
The anemometer containsa smallAC generator.
The generatorconsists of afour pole magnet
attachedto the rotor shaft. Asthe magnet rotates it
inducesavoltageina coilofwire mountednearby.
Thisvoltage istransmittedtotheelectronics pack-
agevia thesensor cable. Theanemometer issup-
pliedwithan 10inchlongstubmast with0.50”
outsidediameter and60feet ofcable.
The A75-302 WindVaneis injectionmolded of
black ultravioletstabilized Lexan. The wind vane
shaftis supported by two shieldedstainlesssteel
precisionballbearings. Allmaterialsare corrosion
resistant. Thewind vane issupplied with anS-
shapedaluminummast0.50”outsidediameterand
60feetof cable.
The wind vane isdirectly coupled to a precision
conductiveplastic potentiometer located in the
main body. An analog voltagelinearly propor-
tionalto winddirection is produced whena con-
stantexcitationvoltage isappliedto thepotentiom-
eter.
TheTransmitterconvertstheACfrequencyfromthe
anemometertoadccurrent.Variationin theampli-
tudeof thewind speedsignal doesnotaffect the
accuracyofthe outputsignal.Theoutputcurrent
variesfrom 4ma withno windto 20maatfullscale.
TheTransmitterconvertstheoutputvoltage fromthe
windvane,whichisproportional toazimuth,toadc
current. Thecurrentvaries linearlyfrom 4maat
zero degrees to 20 ma at 360 degrees or 540. The
transmitterprovidesa regulateddc voltagefor
excitationofthewinddirection potentiometer.
TheTransmitteris looppowered andprotected from
damageby reverse polarity. The wind speedand
directioncircuitsaretotally separateandelectrically
isolatedfrom oneanother. Allcircuitsare protected
fromdamageby highvoltagetransients suchas
lightningbymetaloxidevaristors. Theavailable
NEMA12 enclosure hastwo 1/2"romex connec-
torslocated on thebottomof the boxthat provide
entryforcabling.

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Figure3
SensorMounting

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Figure4
Poor WindSensorPlacement
OverVerticalWall

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INSTALLATION
SENSORS
Thesensors shouldbe mountedat thepoint atwhich
itisdesiredtosample thewind. Typically,it is
locatedas highas feasibleand wellclear ofobstruc-
tions.
Theymaybemountedon anexistingstructure, ona
naturalformation, or ona mast ortower. It is
desirabletomountthemso thatthesupporting
structurewillnotinfluencethewindcharacteristicsin
theirimmediatevicinity. Ifthey aremountedabovea
rooftoporsimilarbuildingstructuretheyshouldbe
highenoughso thatthewinddeflectedoffthe
structurewillnot affectthem,typically 5to10 feet
ormore.
Ifmounted tothesideofa supportingstructure they
shouldbe mountedatleasttenstructure diameters
awayfrom the structurein ordertotake thesensors
outof thedisturbed airaround thestructure. They
shouldbemounted towardtheprevailingwindand
shouldbepositionedsothat theinfluence ofstruc-
turalmembersisminimized.
Ifthesystemisto monitorwindcharacteristics fora
proposedwind poweredgenerator,the altitude
shouldbe at least 30feet above the groundor the
supportingstructure forthewindgeneratortower. If
ahorizontal-axis machineisproposed,itis accepted
practiceto mountthe anemometerhead atthe
machine’scenterof rotation.
Apreferredmountingwhichiscommonly usedisa
telescopictowerforinstallationsuptofortyorfifty
feethigh.Atowercommonlyused forTVantenna
support,consistingofconcentricpiecesoftubing
approximatelytenfeet long,guyedateachsection, is
suitable. Abovethisheightself-supporting orguyed
lightweightstructuraltowerscanbeused.
Ifthe sensors areto bemountedon ametallic tower
considerationmustbegiventogalvaniccorrosion
whichoccursbetweendissimilarmetals. Attachment
ofaluminumboomstogalvanizedsteeltowersusing
stainlesssteel hoseclampsis acceptable.
Forothercombinations ofmetalsrecommended
practiceis toelectrically insulatetheboom fromthe
towerwith aplasticbushingorsheet. Preferably
fabricatea boomfrom thesame materialas the
tower. Thisconsiderationisespeciallyimportantin
locationsexposed tosaltspray andair.
Anemometer
Notethe locationof the1/8"diameterholesinthe
anemometerbase and inthe topofthe stubmast.
Donotpress on theanemometerrotor as the
bearingmay bedamaged. Grasp theanemometer
aboutits lower body andpress it ontothe stub mast.
Alignthe1/8"holesand securetheanemometerto
thestub mastby passingthecotterpinthrough these
holes. Attachthe stub mast tothe tower or other
supportusingthetwostainless steelhoseclamps.
Slidethe protective bootoverthe base ofthe
anemometerafter wiringiscomplete. Tape ittothe
mastto secureit inplace.

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WiringConsiderations
Thewiretypeisnon-criticalformost applications.
Ifthewiringislocatedinanelectricallynoisy
environmentthenthe useofatwistedpairwith
shieldis recommended. Connecttheshield to
groundatone endonly.Theinsulationshouldbe
sunlightresistant.Polyethyleneorpolyvinylchloride
insulationisrecommended.
Beforeproceedingverifythatthemaximum resis-
tanceofthecurrent loopincludingthewiringand
sensingelementdoesnotexceed themaximum
givenbyFormula1.If thisresistance isexceeded
theloopcurrentwillnotattainfullscale.
WindVane
Itisusually desirabletorelate thewinddirection
readingsto TrueNorth.Ifamagnetic compassis
usedthe deviationfrom TrueNorth mustbe deter-
mined. Atopographicalmapcontainsthisinforma-
tion.For exampleifthedeviationis 15degrees
West, a magneticcompass willindicate 15degrees
whenpointed atTrueNorth. Ifthe deviationis East,
thensubtract itfrom 360to obtainthe readingfor
TrueNorth.
Thebase ofthe windvane hastheletter “N”with an
arrowmolded intoit.Refer toFigure 3.This must
beorientedso that it istowardthe North. The
vane’smountingholesareoriented suchthatthe “S”
mast isona North -Southline with respecttothe
vane.Forinstallationsusinglarge,climbabletowers
thevanemay beorientedbypivotingthe “S”mastin
thehose clamps. Forsmaller towerspivot theentire
toweruntilthe“S”mastisproperlyaligned.
Donotpress on the top ofthe vane as it may
damagethebearings.Toinstallthewind vane,grasp
itabout itslower bodyand pressitwithatwisting
motionontothemast.Alignthe1/8"holesinthe
baseof thewindvanewiththeholesin the“S” mast.
Securethe vane tothe mastbypassing thecotter pin
throughtheholes.
Slidethe protective bootover the baseof thewind
vaneafter wiringis complete. Tapeit’s basetothe
mastto secureit inplace.

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Anemometer
1. Refer to Figures 3 & 5. Connect the sensor cable
to the anemometer using the end with the attached
lugs. Polarity is not important. There are two brass
studswith4-40 threadthatextendfrom thebottomof
theanemometer housing.Attach the sensorcableto
thesestuds beingcarefulto tightenonly the outer#4
hex nut to 3 inch-pounds torque. If the inner nut is
loosenedorthe nutsaretightened simultaneouslythe
studmay rotate. This may resultin a poorelectrical
connectioninside theanemometer. See Figure3.
2.Connectthe anemometer cabletoterminals X3.1
&X3.2ofthetransmittercircuitboard. Polarityisnot
important.
WindVane
It is recommended that the system be as-
sembledandtestedonthe ground before final
installation.
1. Refer to Figures 3 & 5. Connect the Red wire
ofthesignal cable to theDirectionVanePositive
terminal.Tightenwindvaneterminalto3inch
pounds.
2. Connect the Green (or White) to the Direc-
tionVaneNegativeterminal.Tightenwindvane
terminalto3 inchpounds.
3. ConnecttheBlack wire ofthesignal cable to
theDirectionVaneSignal terminal.Tightenwind
vaneterminalto 3inchpounds.
4. Connect the Redwire fromthe wind vane to
transmitterboard terminal X3.3 “+”.
5.Connectthe Black lead fromthewind vane to
thetransmitter boardterminal X3.5 marked SIG”.
6. ConnecttheGreen(orWhite)lead from the
windvanetotransmitterboard terminal X3.4
marked“-”.
Shouldadditional cableberequired upto 1000feet
maybecarefullysplicedinto theexistingcable.
Take care to preserve the color code. AWG #18 -
#22stranded copper wirewith shield is recom-
mended.
Securethe sensorcable tothesupporting structure
atintervals offour feet orless. If thecable is
allowedto vibratein thewind abroken cablemay
result.
OperatingPower
Connecta suitable power sourceto the power
terminalstripX2asfollows:
ACOperating Power
X2.1 AC Line 1 or Hot
X2.2 ACLine 2 orNeutral
X2.3 EarthGround
DCOperating Power
X2.4 Positive
X25 Negative
Note: When circuitboard isconfiguredfor only
DCoperatingpower the connector for X2.1, X2,2
X2.3maynot be present.

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Figure5
ComponentLayout