Specifications

CommStat 4 PDS 8.2011 rev 45
CommStat 4 Lead/Lag Controller Outputs (cont'd)
blowerwillbeenergizedwithaDCinverter(ifaninverterispresent).Thereisa2°F(1°C)differential
for this alarm to reset. The temperature for the second stage high temperature alarm can be selected in
screen #7 of the Configuration Menu.
11. Smoke alarm
The smoke alarm is energized when the smoke detector inputs sense a smoke fault condition. All outputs
are off and the smoke alarm relay is energized during a smoke fault. This is a dry contact output that can
beconfiguredforNOorNC(default)operationinsetting#18oftheconfigurationmenu.
The smoke alarm has two selections -Manual(default)andAuto. If Manual is selected, a physical reset
of the fault is required by holding the Up and Down buttons for 4 seconds. Cycling power will not reset a
smoke fault if Manual is selected.
If Auto is selected the alarm will reset after an adjustable time delay of 3-10 minutes. Screen #17 in the
Configuration Mode allows the user to determine how the smoke alarm relay reset will be configured.
12. Mixed Air Relay (MAR)
The MAR output is be energized by the CommStat 4 when the second stage high temperature alarm has
been activated. This is referred to as the Emergency Ventilation Mode.
13. DC Air Mover Relay (AMR)
The DC Air Mover Relay has a dry contact output and is energized in the Emergency Ventilation Mode.
14. AUX1 and AUX2
 TheCommStat4hastheoptionfortwo,drycontact,auxiliaryoutputsthatareenergizedbasedonthe
AUX1andAUX2inputs.EachAUXinputcanbeconfiguredtolookforanormallyopen(NO)ornormally
closed(NC)signalinconfigurationscreens#21and#22.Eachconfigurationscreenallowstheuserthe
option of NO, NC, or OFF(default)todisablethefeature.TheAUX1andAUX2outputsprovideaNO,
NC,andCOMterminal.Note:AUX1andAUX2arenotavailablewhentheEconomizerconfiguration2is
selected in screen 19.
Important Safety Precautions
WARNING
ALWAYS TURN OFF POWER AT THE MAIN POWER SUPPLY BEFORE INSTALLING, CLEANING, OR
REMOVING THERMOSTAT.
•Thisthermostatisfor24VACapplicationsonly;donotuseonvoltagesover30VAC
•Donotshortacrossterminalsofsystemcontroltotestoperation;thiswilldamageyourthermostatandmay
void your warranty
•Allwiringmustconformtolocalandnationalelectricalandbuildingcodes
•Usethisthermostatonlyasdescribedinthismanual
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