Temperature sensor operation and checkout, C7089u outdoor temperature sensor, Operation in heat mode – Honeywell COMMERCIALPRO TB7220 User Manual

Page 20: Operating sequence, Second stage heat and cool control, Operation, Checkout

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TB7220 COMMERCIALPRO™ PROGRAMMABLE THERMOSTAT

63-2635—03

20

NOTE: There is a 5°F deadband between Compressor and

Auxiliary Heat lockout temperatures

Operation in Heat Mode

When the outdoor temperature is:

— Below Compressor Lockout Temperature: only Auxiliary

Heat operates.

— Above Auxiliary Lockout Temperature: only the Compressor

operates.

— Between the two temperatures: both the Compressor and

Auxiliary Heat operate.

Fig. 41. Heat Pump Operation with Lockout Temperatures

Set.

Operating Sequence

The thermostat energizes specific terminal(s), depending on

the demand for heating, cooling or fan. The thermostat screen

shows the time, inside temperature, system and fan selections.

Additional indicators are shown when the heating, cooling or

fan is energized. See Tables 9 and 10 for specification

information.

Table 9. Sequence of Operation for Conventional Systems.

a

If Installer Setup System type is set to two stages of cooling.

b

G energizes only if Installer Setup 0180 is set to Electric.

c

If Installer Setup System type is set to two stages of heating.

Table 10. Sequence of Operation for Heat Pump Systems.

a

Configure O/B in Installer Setup. Based on last piece of

equipment called (cooling = O; heating = B).

b

If Installer Setup System Type is set to 3Heat/2Cool Heat

Pump with Auxiliary Heat.

c

If Installer Setup System Type is set to 2Heat/1Cool Heat

Pump with Auxiliary Heat.

d

This terminal does not energize if Installer Setup System type

is set to 2 Heat/2 Cool Heat Pump with no Auxiliary Heat.

Second Stage Heat and Cool Control

While maintaining setpoint, several factors affect when 2nd

stage energizes such as load conditions, environmental

conditions, P+I control, and home insulation. The second stage

energizes when the thermostat senses 1st stage is running at

90% capacity. This operation is droopless control.

Temperature Sensor Operation and Checkout

Allow outdoor or indoor temperature sensor to absorb the air

for a minimum of five minutes before taking a reading. See the

Sensor instructions for more information.

NOTE: The C7089U, C7189U, and T7770A Temperature

Sensors are calibrated at the factory and cannot

be recalibrated in the field.

C7089U Outdoor Temperature Sensor

Operation

When installed with Thermostat ISU 0340 set to 1 or 2, the

thermostat can display outside temperature.

Checkout

Allow C7089U Outdoor Sensor to absorb outdoor air for a

minimum of twenty minutes before taking a reading.

With an accurate thermometer (±1°F [0.5°C]) measure the

temperature at the sensor location, allowing time for the

thermometer to stabilize before reading.

System

Setting

Fan

Setting Call for Action

Energize

Terminals

Screen

Message

Off

Auto

Cool

Auto

Cool

or Auto

Auto

Stage 1

Cooling

Y, G

Cool On

Cool

or Auto

Auto

Stages 1 and 2

Cooling

Y, Y2

a

, G

Cool On

Heat

Auto

Heat

or Auto

Auto

Stage 1

Heating

W, G

b

Heat On

Heat

or Auto

Auto

Stages 1 and 2

Heating

W, W2

c

, G

b

Heat On

35

M19950

COMPRESSOR
LOCKOUT
TEMPERATURE

AUXILIARY
LOCKOUT
TEMPERATURE

COMPRESSOR ONLY

BOTH COMPRESSOR AND

AUXILIARY HEAT

AUXILIARY ONLY

50

OUTDOOR TEMPERATURE

System

Setting

Fan

Setting Call for Action

Energize

Terminals

Screen

Message

Off

Auto

O/B

a

Cool
Cool

or Auto

Auto

Stage 1 Cooling

Y, G, O/B

a

Cool On

Stages 1 and 2

Cooling

Y, Y2

b

, G,

O/B

a

Heat Auto

None

O/B

a

Heat

or Auto

Auto

Stage 1 Heating

Y, G, O/B

a

Heat On

Stages 1 and 2

Heating

Y, W1

c

, G,

O/B

a

Auxiliary

Heat On

Stages 1, 2 and 3

Heating

Y, Y2

b

,

W1

d

, G,

O/B

a

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