Carrier 33CS Installation And Operating Instructions Manual

Also see for 33CS: Owner's manual Owner's manual Operating guide Installation, start-up, and operating instructions Installation, start-up, and operating instructions

Contents

Carrier 33CS Installation And Operating Instructions Manual Manual pdf 9 page image

9Dual Set Point Operation — When the thermostat isconfigured for dual set point operation, there are separate heatand cool set points. The adjustable set point range is 35 to 99 F(2 to 36 C). When the thermostat is in Heat or Cool mode, theset points can be adjusted to any temperature within the operat-ing range.When the thermostat is in Auto mode, the thermostat willnot allow the Cool set point to be lower than the Heat set point.The thermostat will also use the programmed Deadband value(Advanced Setup Step 6) to determine the minimum differencebetween the Heat and Cool set points. If the Deadband is set for6 degrees, the Cool set point cannot be set within 6 F of theHeat set point.When entering Auto mode from Heat or Cool modes, theHeat and Cool set points will remain spread apart by the sameamount when the set points are adjusted. For example, if theCool set point is 80 F (adjusted in Cool mode) and the Heat setpoint is 70 F (adjusted in Heat mode), when entering Automode, both set points would be adjusted by the same amountwhen the UP and DOWN arrow buttons are pressed. There-fore, if the DOWN ARROW was pressed 5 times, the Cool setpoint would be 75 F and the Heat set point would be 65 F. Toadjust the set points individually, enter the Heat or Cool modesfirst.Outside Air Temperature Sensor — Press and holdthe Fan button for 2 seconds to display outside temperature(if optional outdoor sensor is wired to thermostat). Press anybutton to return to normal operation.Locking Cover — A locking cover with tamper-proofscrews is provided with the thermostat. The locking cover canbe used to keep the thermostat set points and configurationsfrom being changed. A special tool is required to remove thecover.Dry Contact Switch/External Control — A drycontact switch is provided to allow an external device to forcethe thermostat into the Unoccupied set points configured inAdvanced Setup Step 13. When the thermostat is forcedinto Unoccupied set points via the dry contact closure, theUnoccupied icon will blink each second. The external device iswired to contacts CK1 and R. See Fig. 4.NOTE: More than one thermostat is not required. All thermo-stats wired to the external device will enter Unoccupied modesat the same time.TROUBLESHOOTINGTable 4 — TroubleshootingPROBLEM SOLUTIONThe fan always runs in Low speed, even with no temperaturedemand.This is normal operation of the thermostat. If the fan needs to be shut off,switch mode to Off. The fan will not run in the unoccupied mode when there isno call for heating or cooling.The fan will not run in all three speeds or switches speeds inimproper order.Wiring between the thermostat and the relay board or between the relay boardand the fan is incorrect. Check the wiring for proper connection.Cold water valve opens for both a cool or heat demand in a4-pipe system.Check the configuration of Advanced Setup Step 3. Configuration should beset for 4-pipe system.Valve does not open in 2-pipe system. Wiring or configuration is incorrect. Check the configuration of AdvancedSetup Step 3. Configuration should be set for 2-pipe system. Make sure watervalve is wired to the Y1 terminal.Thermostat displays large set point instead of roomtemperature.This is the normal display when the thermostat is set to single set point insteadof dual set point (Advanced Setup Step 2).The thermostat will only allow Heat or Off modes in 2-pipeinstallations, even though chilled water is available.Changeover sensor is faulty, improperly wired, or improperly installed. Confirmproper wiring of the changeover sensor. Confirm proper placement of the sen-sor. If wiring and placement are proper, check the changeover sensor with anohmmeter as follows:1. Remove power from the fan coil system.2. Disconnect wiring between the sensor and the thermostat.3. Place an ohmmeter between R and the wire just disconnected from thethermostat.4. The sensor should show continuity whenever the water temperature is con-firmed to be at or below 65 F. If the sensor is open when the water tempera-ture is at or below 65 F, replace the sensor.

/ 12

Related manuals for Carrier 33CS