Honeywell T834C Installation Instructions Manual page 5

Adjust the heat anticipator to match the reading on
the ammeter.
Disconnect the ammeter, reconnect the W wire, and
mount the thermostat. Continue with system
checkout.
NOTE: For best performance, the heat anticipator may
require further adjustment. To lengthen the
burner-on time, move the indicator toward the
LONGER settings in the direction of the arrow
Do not adjust the anticipator more than
shown.
one-half scale marking at a time
shorten the burner-on time, move the indicator in
the opposite direction.
Heat Anticipator Settings
Heat pump systems (for about 3 cycles per hour):
Using B terminal:
Set adjustable anticipator to 130 percent of com-
bined 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 ampere because cooling
anticipator provides anticipation during heat cycle
in this hookup.
Electric systems (with auto fan in heat):
Set adjustable anticipator to combined current draw of
heating and fan relays.
Other systems (without auto fan in heat):
Set adjustable anticipator to current draw of heat relay
or valve.
CHECKOUT
CAUTION
Do not check operation by shorting across
terminals of system controls. Can cause damage
to heat anticipator.
IMPORTANT
To assure accurate temperature control, do not
touch or breathe on the bimetal or thermometer.
Heating
With SYSTEM switch set at HEAT and FAN switch at
AUTO, move the temperature setting lever about 10°F
(6°C) above the room temperature:
Gas- or oil-fired systems: heating should start; fan should
start after a short delay.
Central electric heat or heat pump systems: both heating
and fan should start. Move the temperature setting lever
about 10°F (6°C) below the room temperature.
Gas- or oil-fired systems: heating and fan should shut off
after a short delay.
Electric heat or heat pump systems: heating and fan
should shut off.
T834C,T8034C HEATING-COOLING TRIPLE FUEL THERMOSTATS
Cooling
NOTE: To prevent compressor short cycling, some
. See Fig. 1. To
With the SYSTEM switch set at COOL and the FAN switch
at AUTO, move the temperature setting lever about 10°F
(6°C) below the room temperature. Cooling and fan should
start (see NOTE above). Move the temperature setting
lever about 10°F (6°C) above the room temperature.
Cooling and fan should shut off.
Fan
With the SYSTEM switch set at OFF, and the FAN switch
at ON, the fan should run continuously. Move the FAN
switch to AUTO. In gas- or oil-fired systems, fan operation
is controlled by the plenum fan control in heating and by
the thermostat in cooling. In central electric heat and heat
pump systems, fan operation is controlled by the thermostat
in both heating and cooling.
Recalibration
These thermostats are calibrated at the factory and should
not require recalibration. If the thermostat needs adjustment,
first check for accurate leveling.
Check the calibration as follows:
If needed, perform recalibration as follows:
5
CAUTION
Do not operate cooling if outdoor temperature is
below 50°F (10°C). Refer to manufacturer
recommendations.
manufacturer equipment includes a minimum off-
timer to provide a five-minute time delay from
when the thermostat last turned off the compres-
sor, or from when the system first received
power. This delay protects the compressor.
Move the temperature setting lever to the lower end
of the temperature scale. Place the SYSTEM switch
in the OFF position. Wait at least five minutes.
Remove the thermostat cover. Move the setting
lever until the switch just makes contact. The
mercury in the switch rolls to the left end of the tube.
Replace the cover and wait five minutes for the
cover and the thermostat to lose the heat it has
gained from your hands. If the thermometer pointer
and the setting lever indicator read approximately
the same, no recalibration is needed.
Place the temperature setting lever at the same
setting as the thermometer. Remove the cover by
pulling outward on the right edge of the cover until it
snaps free of the thermostat base.
Insert 104994A Calibration Wrench (ordered
separately) onto the hex nut under the coil. See
Fig. 5. Hold the setting lever tight and turn the
wrench clockwise until the mercury rolls to the right
end of the tube. Remove the wrench and replace
the cover.
NOTE: To assure accurate temperature control, do
not touch or breathe on the bimetal or
thermometer.
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