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T8034C HEATING/COOLING THERMOSTATS
Fig. 9. Heat Pump Wiring for T8034C.
SETTING AND ADJUSTMENT
System and Fan Switching
The T8034C features SYSTEM and FAN switches for
control of the heating-cooling and fan systems.
The SYSTEM switch controls system operation as follows:
HEAT: Only heating system operates.
OFF: Both heating and cooling systems are off.
COOL: Only cooling system operates.
The FAN switch controls fan operation as follows:
AUTO: In standard systems, fan operates in response
to the thermostat in cooling; fan operates in
response to the plenum fan control in heating. In
heat pump or electric heat systems, the fan operates
in response to the thermostat in heating and cooling.
ON: The fan runs continuously.
To switch positions, slide the lever to the desired position.
Place the switch lever directly over the desired indicator
mark for proper circuit operation.
Heat Anticipator Setting
IMPORTANT
The T8034C Thermostat has an adjustable heat
anticipator and operates properly ONLY IF THE
ANTICIPATOR IS ADJUSTED TO MATCH THE
CURRENT DRAW OF THE PRIMARY CON-
TROL. Use this thermostat only on systems with
current draws that fall within the range of the heat
anticipator. Do not use this device on Powerpile
(millivolt) systems.
A current rating is usually stamped in the nameplate of the
primary control. Set the adjustable heat anticipator
indicator to match the value given on the nameplate.
H1
TEMP. FALL
C1
1
POWER SUPPLY. PROVIDE DISCONNECT
MEANS AND OVERLOAD PROTECTION
AS REQUIRED.
HEAT RELAY
FAN RELAY
FAN SWITCH
ON
AUTO
COOL
OFF
HEAT
COOL
OFF
HEAT
SYSTEM
SWITCH
C1
ANTICIPATOR
H1
ANTICIPATOR
M13313
B
O
W
Y
G
R
L1
(HOT)
L2
1
CHANGEOVER
RELAY (HEAT)
CHANGEOVER
RELAY (COOL)
COMPRESSOR
RELAY
5
4
If the current rating is not available:
1.
Turn off the power.
2.
Wire the thermostat, but do not mount it on the wall.
3.
Connect an ammeter between the W wire and W
terminal on the thermostat (in series with the primary
control).
4.
Prepare the system for operation.
5.
Turn on the power.
6.
Turn the system switch to heat.
7.
Increase the thermostat setpoint as necessary to get
the system operating.
8.
With the system operating through the ammeter,
wait one minute, then read the ammeter.
9.
Turn the system switch to OFF, and turn off the
power.
10.
Adjust the heat anticipator to match the reading on
the ammeter.
11.
Disconnect the ammeter, reconnect the W wire, and
mount the thermostat. Continue with system
checkout.
The heat anticipator could require further adjustment for
best performance. To lengthen the burner-on time, move
the indicator in the direction of the
longer
arrows—not
more than one-half scale marking at a time. To shorten the
burner-on time, move the indicator in the opposite
direction.
Most one-stage heating equipment is designed to operate
at five to six cycles per hour, at 50 percent load conditions.
When using a T8034 Thermostat in heat pump systems,
set the heat anticipator at 140 percent of the actual
primary control current draw to reduce the cycling rate.
Most heat pump systems should cycle 2-1/2 to 3 times per
hour.
