TB8220U COMMERCIAL VISIONPRO™ PROGRAMMABLE THERMOSTAT
13 62-3070—03
— When the Minimum Off Timer expires, “Cool On” or
“Heat On” (heat pumps only)” appears solidly in the
display and the compressor and fan turn on.
Outdoor or Indoor Temperature Sensor
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.
Economizer/TOD Logic (Table 6)
Table 6. Operation of Terminal A.
Heat Pump Temperature Lockouts

Dual Fuel Heat Pump and Outdoor Sensor

In this operation, there is no external fossil fuel kit (dual
fuel kit) installed; the thermostat controls this function:
1. Choose correct heat pump application in Installer
Setup Number 0170.
2. Choose Outdoor Temperature Sensor for Heat
Pump Temperature Lockouts Option in Installer
Setup Number 0340.
3. Choose appropriate Balance Point Temperature
in Installer Setup Number 0350.
OPERATION IN HEAT MODE ABOVE BALANCE POINT
(OUTDOOR TEMPERATURE)
When the outdoor temperature is above the selected
Balance Point Temperature (ISU 0350), only the
compressor operates and the fan (G terminal) energizes
when the thermostat calls for heat.
OPERATION IN HEAT MODE BELOW BALANCE POINT
(OUTDOOR TEMPERATURE)
When the outdoor temperature is below the selected
Balance Point Temperature (ISU 0350), only the Fossil
Fuel (auxiliary heat) operates and the fan (G terminal)
does not energize when the thermostat calls for heat.

Heat Pump with Auxiliary (Backup) Heat and

Outdoor Temperature Sensor

1. Choose correct heat pump application in Installer
Setup Number 0170.
2. Choose Outdoor Temperature Sensor for
Control Option in Installer Setup Number 0340.
3. Choose Compressor Lockout Temperature in
Installer Setup Number 0350.
4. Choose Auxiliary Lockout Temperature in
Installer Setup Number 0360.
NOTE: There is a 5°F deadband between Compressor
and Auxiliary Heat lockout temperatures.

Operation in Heat Mode

When the outdoor temperature is:
— Below the Compressor Lockout Temperature, only the
Auxiliary Heat operates.
— Above the Auxiliary Lockout Temperature, only the
Compressor operates. See Fig. 31.
— Between the two temperatures, both the Compressor
and Auxiliary Heat operate.
Fig. 27. Heat Pump Operation with Lockout
Temperatures Set.
Effective
Occupancy
Call for
Cool
Terminal A
Economizer TOD
Occupied — Energized Energized
Unoccupied Yes Energized De-ene rgized
No De-energized De-energized
Override — Energized Energized
35
M19950
COMPRESSOR
LOCKOUT
TEMPERATURE
AUXILIARY
LOCKOUT
TEMPERATURE
COMPRESSOR ONLY
BOTH COMPRESSOR AND
AUXILIARY HEAT
AUXILIARY ONLY
50
OUTDOOR TEMPERATURE