Specifications

ManualsBrandsCarrier ManualsConsumer electronicsCARRIER COMFORT SYSTEM 33CS

When zone temperature conditions exceed the desired oc-

cupied level, if ﬁrst stage heating or cooling is able to im-

prove the occupied level, second stage heating or cooling is

not required.

The monitor thermostat uses Optimized Staging to follow

zone conditions and determine when use of ﬁrst stage is im-

proving zone conditions. If zone conditions are not improv-

ing, or are becoming worse, the monitor thermostat will en-

ergize the second stage of heating or cooling.

System Status Display — The monitor thermostat in-

dicates the system mode and equipment operation by dis-

playing system annunciators. FAN is displayed when the

monitor thermostat energizes the fan relay. COOL is dis-

played when the monitor thermostat energizes a cooling re-

lay. HEAT is displayed when the monitor thermostat ener-

gizes a heating relay. When a second stage of heating or cooling

is energized, a decimal point is displayed between the set

points.

System Mode Reselect — The System Mode Rese-

lect function is the amount of time the monitor thermostat

will wait between checking for a change in system mode.

The System Mode Reselect option is conﬁgured through cat-

egory 4, option 16. The range of values is 0 to 480 minutes

in 1 minute increments. The default is 30 minutes.

System Mode Reselect is activated when the following

requirements are met:

• the monitor thermostat is conﬁgured as a VVTt Monitor

or Monitor Only thermostat

• the monitor thermostat is in system heating or cooling mode

• there are simultaneous zone callers for both heating and

cooling.

If there are simultaneous heating and cooling callers for

the entire length of the System Mode Reselect and there are

more callers for the opposite mode with greater demand, the

monitor thermostat uses the system mode function to select

a new system mode. If the monitor thermostat chooses the

system mode opposite from the currently selected system mode,

it releases the current system mode and initiates the new sys-

tem mode. If the monitor thermostat chooses the same sys-

tem mode as currently selected, it continues in that system

mode. If the monitor thermostat cannot select a system mode

because system mode demand cannot be attained, it releases

the current system mode.

To disable the System Mode Reselect option, conﬁgure

the value to zero.

System Time Guards — The monitor thermostat has

different system time limits (time guards) which prevent an

individual system heating or cooling mode from being se-

lected after the system mode has been released or after the

monitor thermostat receives power.

HIGH/LOW TEMPERATURE LIMITTIME GUARD — This

feature functions to keep the HVAC equipment operating to

reduce equipment cycling. By monitoring the supply-air tem-

peratures, the monitor thermostat can adjust operation to pre-

vent tripping of the heating/cooling temperature limits.

When the supply-air temperature exceeds the ﬁrst or sec-

ond stage Heating or Cooling Temperature Limit the corre-

sponding stage of heating or cooling is disabled.

If the monitor thermostat is in a system mode, it will re-

energize the appropriate stages of heating or cooling when

10 minutes have passed and the supply-air temperature is no

longer exceeding the ﬁrst or second stage Heating or Cool-

ing Temperature Limit.

During equipment operation, when a limit is exceeded,

the following relays are deenergized:

• Second Stage Limit. The second stage relay (H2 or C2) is

deenergized.

• First Stage Limit. The ﬁrst stage relay (H1 or C1) is

deenergized.

NOTE: When both ﬁrst and second stage Heating or Cool-

ing Temperature Limits are exceeded during a system mode,

if the reference zone is no longer a zone caller and there are

zone callers for the opposite system mode, the monitor ther-

mostat ends the current system mode.

Construction System thermostats do not perform LAT (Leav-

ingAir Temperature) checking. Monitor-Only and VVT Moni-

tor thermostats receive supply-air temperature information

from the monitor thermostat, the bypass controller, each zone

controller zone damper supply air temperature sensor asso-

ciated with the system, and from the DX Coil Temperature

Sensor.

The highest and lowest supply-air temperatures are then

used to determine when a Heating or Cooling Temperature

Limit is exceeded.

When the LAT Monitoring option is set to ON, the moni-

tor thermostat maintains system heating and cooling supply

air temperature limits and enables the LAT algorithm.

When the LAT Monitoring option is set to OFF, the moni-

tor thermostat will not maintain heating and cooling supply

air temperature limits and the LAT algorithm is disabled.

To conﬁgure the LAT Monitoring option, set category 4,

option 4. Use the left set point buttons to toggle the option

ON and OFF. The default is ON.

First Stage Cooling Temperature Limit — If the entering air

temperature drops below the First Stage Cooling Tempera-

ture Limit and the LAT Monitoring function is ON, the moni-

tor thermostat will deenergize ﬁrst stage cooling.

To conﬁgure the First Stage Cooling Temperature Limit

option, set category 4, option 5. Use the left set point but-

tons to raise or lower the set point until the desired tempera-

ture is shown. The range of acceptable values is 40 to 45 F,

in one-degree increments. The default is 45 F.

NOTE: The ﬁrst stage limit cannot be set higher than the

second stage limit.

Second Stage Cooling Temperature Limit — If the entering

air temperature drops below the Second Stage Cooling Tem-

perature Limit and the LAT Monitoring function is ON, the

monitor thermostat will deenergize second stage cooling.

To conﬁgure the Second Stage Cooling Temperature Limit

option, set category 4, option 6. Use the left set point but-

tons to raise or lower the set point until the desired tempera-

ture is shown. The range of acceptable values is 45 to 50 F,

in one-degree increments. The default is 50 F.

First Stage Heating Temperature Limit — If the duct tem-

perature entering-air temperature rises above the First Stage

Heating Temperature Limit and the LAT Monitoring func-

tion is ON, the monitor thermostat will deenergize ﬁrst stage

heating.

To conﬁgure the First Stage Heating Temperature Limit

option, set category 4, option 7. Use the left set point

buttons to raise or lower the set point until the desired tem-

perature is shown. The range of acceptable values is 110 to

180 F, in one-degree increments. The default is 110 F.

Second Stage Heating Temperature Limit — If the duct tem-

perature entering-air temperature rises above the Second Stage

Heating Temperature Limit and the LAT Monitoring func-

tion is ON, the monitor thermostat will deenergize second

stage heating.

To conﬁgure the Second Stage Heating Temperature Limit

option, set category 4, option 8. Use the left set point

buttons to raise or lower the set point until the desired tem-

perature is shown. The range of acceptable values is 105 to

160 F, in one-degree increments. The default is 105 F.