Sequence Of Operations - Honeywell T8024D Product Data

POWER
SUPPLY
LOGIC/
CONTROL
CIRCUIT
STAGE 1
HEAT OR
COOL
K1
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
THERMOSTAT
R W
1
L1
(HOT)
L2
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND
OVERLOAD PROTECTION AS REQUIRED.
Fig. 17. Connect resistor to the TACO zone
valve terminal numbers 1 and 2.
FAN Switch Settings
Auto
On
Auto
Auto
a
When the Fuel switch is in the E position.
T8000C, T8001C AND T8024D PROGRAMMABLE THERMOSTATS
THERMOSTAT
SYSTEM
SWITCH
HEAT
OFF
COOL
FAN
SWITCH
E F
FUEL AUTO
SWITCH
Fig. 16. T8001C hardwired internal schematic.
TACO ZONE VALVE
RESISTOR
1
2
3
M11677
Table 3. Sequence of Operations.
SYSTEM Switch Settings
Off
Any
Cool
Heat
ON

Sequence of Operations

The Fan, Heat and Cool outputs are relay or mosfet
controlled. A loss of ac power or a change in the SYSTEM
switch setting can cause the outputs to turn off. The truth
table shows the sequence of operations for the FAN settings
and SYSTEM modes. See Table 3, Sequence of Operations.
Minimum Off-Timer
A minimum off-timer in the T8000C and T8001D assures that
the compressor does not come on again for at least five
minutes after it turns off. The minimum off-timer is triggered
when the compressor turns off and when the SYSTEM switch
position is changed. If the compressor turns off when the
setpoint is changed, the minimum off-timer is triggered. Power
interruption and power restoration also trigger the minimum off-
timer. The minimum off-timer operates in cooling on the
T8000C and T8001C. A flashing snowflake
minimum off-timing is in effect.
Call for Action Energize Terminals
None
Any
Cooling
Heating
11
WALLPLATE SYSTEM COMPONENTS
R
C
HEAT RELAY
W
HEAT CHANGEOVER
RELAY
B
COOL CHANGEOVER
RELAY
O
COMPRESSOR
RELAY
Y
FAN RELAY
G
M11731
indicates the
Display Icons
None None
G None
G,Y
a
W,G
L1
(HOT)
L2 1
68-0195–2