Fan Coils
INSTALLATION, OPERATION, & MAINTENANCE MANUAL
17
AppendixA
AdjustmentofICMAW4105
Potentiometer
Low, Med, High CFM adjust
AdjustingtheLow,Medium,andHighpotentiometers
requirestheuseofaMulti-metercapableofmeasuring
0~5vdc.
1. Onlytrainedandqualiedindividualsshould
attempttoadjustorservicecomponentsonany
electricalcomponent.Failuretofollowsafetyrules
couldresultinelectricalshockorhazard.
2. Unitmustbepoweredtoperformthefollowing
procedure.Ifmainpowerisnotavailable,IEC
recommendsconnectingatemporary24V-40VA
powersupplyinparallelwiththesecondaryoutputs
oftheunit’stransformer.
3. SettheelectricalmultimetertoVoltsDirectCurrent
(Vdc)onthe0~5or0~20Vdcscale
4. Attachblack(negative)leadofmetertothe
DCcommonterminal,labeled“L2”abovethe
potentiometersandtotheleftoftheorangerelay.
5. Attachthered(positive)leadofthemetertothe
redwirethatbridgesthe0-10VDCoutputs:high,
medium,andlow.
6. HighSpeed:CloseHighspeedrelaybyapplying
24VtotheHighterminal.Usingasmallscrewdriver
turntheVR3potentiometersothemetermeasures
4.51Vdc.ThiswillsettheECMspeedto90%of
maximumforhighspeed.Openthehighspeed
relay.
7. MediumSpeed:Closemediumspeedrelayby
applying24Vtothemediumterminal.Usinga
smallscrewdriverturntheVR2potentiometerso
themetermeasures3.53Vdc.Thiswillsetthe
ECMspeedto70%ofmaximumspeedformedium
speedoperation.Openthemediumspeedrelay.
8. LowSpeed:Closelowspeedrelaybyapplying
24Vtothelowterminal.Usingasmallscrewdriver
turntheVR1potentiometersothemetermeasures
2.06Vdc.ThiswillsettheECMspeedto40%of
maximumspeedforlowspeedoperation.Openthe
lowspeedrelay.