Operation; Outside Air Temperature Sensor; Locking Cover; Dry Contact Switch/External Control - Carrier 33CS Installation And Operating Instructions Manual

Cool set point is 80 F (adjusted in Cool mode) and the Heat set
point is 70 F (adjusted in Heat mode), when entering Auto
mode, both set points would be adjusted by the same amount
when the UP and DOWN ARROW buttons are pressed.
Therefore, if the DOWN ARROW was pressed 5 times, the
Cool set point would be 75 F and the Heat set point would be
65 F. To adjust the set points individually, enter the Heat or
Cool modes first.
Outside Air Temperature Sensor —
the Fan button for 2 seconds to display outside temperature
(if optional outdoor sensor is wired to thermostat). Press any
button to return to normal operation.
Locking Cover —
A locking cover with tamper-proof
screws is provided with the thermostat. The locking cover can be
PROBLEM
The fan always runs in Low speed, even with no temperature
demand.
The fan will not run in all three speeds or switches speeds in
improper order.
Cold water valve opens for both a cool or heat demand in a
4-pipe system.
Valve does not open in 2-pipe system.
Thermostat display only shows clock.
Thermostat displays large set point instead of room
temperature.
The thermostat flashes "Occupied 1" when in Program
Mode.
The thermostat will only allow Heat or Off modes in 2-pipe
installations, even though chilled water is available.
used to keep the thermostat set points and configurations from
being changed. A special tool is required to remove the cover.
Dry Contact Switch/External Control —
contact switch is provided to allow an external device to force
the thermostat into Occupied 1, Unoccupied, or shut down the
fan coil unit. If the thermostat is forced into Unoccupied set
points via the dry contact closure, the Occupied 1 via the dry
contact closure, the Occupied 1 icon will blink each second.
Press and hold The external device is wired to contacts CK1 and R.
NOTE: More than one thermostat is not required. All thermo-
stats wired to the external device will enter Occupied 1 and
Unoccupied modes at the same time.

TROUBLESHOOTING

Table 5 — Troubleshooting
This is normal operation of the thermostat. If the fan needs to be shut off,
switch mode to Off. The fan will also not run in the unoccupied mode when
there is no call for heating or cooling.
Wiring between the thermostat and the relay board or between the relay board
and the fan is incorrect. Check the wiring for proper connection.
Check the configuration of Advanced Setup Step 5. Configuration should be
set for 4-pipe system.
Wiring or configuration is incorrect. Check the configuration of Advanced
Setup Step 5. Configuration should be set for 2-pipe system. Make sure water
valve is wired to the Y1 terminal.
This is configured in Advanced Setup Step 3. Change Display Blanking config-
uration to Off.
This is the normal display when the thermostat is set to single set point instead
of dual set point (Advanced Setup Step 4).
The sensor connected to the dry contact switch of the thermostat is active,
forcing the thermostat into Occupied mode. If no sensor is connected, set the
Advanced Setup Step 14 configuration to NO (normally open).
Changeover sensor is faulty, improperly wired or improperly installed. Confirm
proper wiring of the changeover sensor. Confirm proper placement of the sen-
sor. If wiring and placement are proper, check the changeover sensor with an
ohmmeter 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 the
thermostat.
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 temper-
ature is at or below 65 F, replace the sensor.
11
SOLUTION
A dry