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T834B; T834C; T834J HEATING-COOLING THERMOSTATS
SETTINGS AND ADJUSTMENT
System and Fan Switching
T834B
The T834B features a SYSTEM switch for control of the
heating-cooling system.
The SYSTEM switch controls system operation as follows:
HEAT: Heating system only operates.
OFF: Both heating and cooling control systems are
disconnected.
COOL: Cooling system only operates.
The fan operates in response to the plenum fan control in
heating; fan operates with cooling equipment in cooling.
T834C
The T834C features SYSTEM and FAN switches for
control of the heating-cooling and fan systems.
The SYSTEM switch controls system operation as follows:
HEAT: Heating system only operates.
OFF: Both heating and cooling control systems are
disconnected.
COOL: Cooling system only operates.
The FAN switch controls fan operation as follows:
AUTO: for conventional (gas, oil or central electric heat)
systems, the fan operates in response to the plenum
fan control in heating; fan operates in response to
the thermostat in cooling. For heat pump systems,
the fan operates in response to the thermostat in
both heating and cooling.
ON: The fan runs continuously.
T834J
The T834J features SYSTEM and FAN switches for
control of the cooling and fan systems.
The SYSTEM switch controls system operation as follows:
OFF: Cooling control system is disconnected.
COOL: Cooling system operates.
The FAN switch controls fan operation as follows:
AUTO: Fan operates in response to the thermostat in
cooling.
ON: Fan runs continuously.
NOTE:
Some electric heat systems require control of fan
operation from the thermostat. These systems
require a thermostat with control of fan operation
in response to a call for heating or cooling.
To switch positions, use thumb and index finger to slide
lever to desired position. Switch lever must stop directly
over desired function indicator mark for proper circuit
operation.
Temperature Setting
Push the temperature setting lever to the desired control
point on the temperature scale. The same lever controls
both heating and cooling. On models with temperature
range stops, temperature setting lever can be moved only
between the two temperature range stops.
HEAT ANTICIPATOR SETTING
IMPORTANT
The T834 Thermostat has an adjustable heat
anticipator and will operate properly ONLY IF
THE ANTICIPATOR IS ADJUSTED TO MATCH
THE CURRENT DRAW OF THE PRIMARY
CONTROL. 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.
Conventional Systems
A current rating is usually stamped on the nameplate of
the primary control. Set the adjustable heat anticipator
indicator to match the value given on the nameplate.
If the current rating is not available, proceed as follows to
determine the rating:
1. Turn off power.
2. Wire thermostat, except for connection to
W terminal, but do not mount it on the wall.
3. Connect ammeter between W wire and
W terminal on the thermostat.
4. Prepare the system for operation.
5. Turn on power.
6. Turn system switch to heat.
7. Increase thermostat setpoint as necessary to get
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
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.
NOTE:
The heat anticipator may require further adjust-
ment for best performance. To lengthen burner-
on time, move the indicator in the direction of the
longer arrows but not more than one-half scale
marking at a time. To shorten burner-on time,
move indicator in opposite direction.
Heat Pump Systems
(for about 3 cycles per hour)
Using B Terminal
Set adjustable anticipator to 130 percent of combined
current draw of compressor and fan relays.
Using O Terminal
Set adjustable anticipator to maximum scale setting. Limit
combined load current of compressor and fan relays to
0.8 amp, because cooling anticipator provides anticipation
during heat cycle in these hookups.
