T500 Series Programmable Thermostats Product/Technical Bulletin
15
Mode
Repeated pressing of the
Mode
button allows
selection from four modes of operation (five for the
T500HPP-1/Heat Pump model):
•
When
the
Snowflake
and the word
COOL
are
displayed, the thermostat is in the cooling mode.
When the thermostat is calling for cooling, the
snowflake will flash.
•
When
the
Flame
and the word
HEAT
are
displayed, the thermostat is in the heating mode.
When the thermostat is calling for heating, the
flame will flash.
•
When
the
Flame
and
E Ht
(emergency heat)
are displayed, the thermostat will control using the
emergency heat with the compressor locked out.
(T500HPP-1/Heat Pump only.)
•
When
the
Snowflake
and the
Flame
symbols
and word
AUTO
are displayed, the thermostat will
automatically change over between heating and
cooling.
Note:
The thermostat never allows less than a 1
°
C
(2
°
F) difference between the heating and
cooling setpoints.
•
When
OFF
is displayed, the equipment will not
operate.
Note:
Use caution when using the
OFF
mode in
extremely cold weather.
Celsius/Fahrenheit
Press the
∨∨∨∨
and
∧∧∧∧
buttons simultaneously to alternate
between Celsius and Fahrenheit display.
F
uzzy Logic Control
Over time, the T500 learns how long it takes the
system to meet the load. If the system can change the
room temperature quickly, the T500 allows the
thermostat to drift further from setpoint before starting
the equipment. If the system takes a longer period of
time to change the room temperature, it will not allow
the temperature to drift as far from setpoint. The T500
also takes into account the minimum On/Off times.
The 2-minute On/Off time allows the equipment to
cycle more frequently at smaller differentials than the
4-minute On/Off time. For multi-stage applications, the
T500 does not bring on the next stage of cooling or
heating if it knows that the system can change the
temperature by 6 degrees in 1 hour, or 1 degree in
10 minutes. To verify thermostat
operation, force the
next stage on by changing the setpoint
more than
2 degrees.
F
an
If continuous fan is not selected, the fan will operate
automatically and the fan symbol will be off. To select
continuous fan operation, press the Fan button. The
fan symbol
will be displayed. (See Figure 20.) See
Smart Fan DIP switch in Table 1.
Mode
Clock
Set Temp
Outdoor
Fan
Program
Resume
Hold
66
4:22
Mo
AM
Press to
select
continuous
fan
operation.
Figure 20: Selecting Continuous Fan Operation
Outdoor Button
When an outdoor temperature sensor (order
separately) is connected to the T500 thermostat, you
can display the current outdoor temperature by
pressing the
Outdoor
button. If the sensor option is
not connected, the thermostat will display “— —”.
See the
Ordering Information
section.
