Operation and checkout, Calibration – Honeywell T4398B User Manual
Page 5
T4398A,B PRECISION ELECTRIC HEATING THERMOSTAT
5
69-1604
OPERATION AND CHECKOUT
After the thermostat is installed and wired, check out normal
operation as follows:
1. Turn setting dial fully clockwise until the switch clicks
and the electric heater starts to heat.
2. Turn the dial fully counterclockwise; the power circuit
breaks and the electric heater starts to cool.
3. The T4398 is a more accurate thermostat, allowing
users to be more comfortable at lower setpoint settings
(saving energy and lowering heating costs). To deter-
mine final setting:
a. Begin with setting the dial indicator at 68°F (20°C).
b. After two operating hours, if not comfortable, adjust
setpoint to raise or lower the temperature, adjusting
temperature only a few degrees each time.
Calibration
IMPORTANT
Do not assume the thermostat is out of calibration
until it is installed and allowed to operate for several
hours.
The T4398 is accurately calibrated at the factory under
controlled conditions. The snap switch turns on heat when the
setpoint is raised to room temperature.
The vapor-filled diaphragm sensor is affected by barometric
pressure and altitude. Deviations up to 1°F (±1/2°C) are within
normal operation. The control point drops 2°F every 1000 ft
(1°C/300m) above sea level. See Fig. 5 and 6.
Fig. 5. T4398 altitude correction in (ft).
Fig. 6. T4398 altitude correction in (m).
To calibrate (see Fig. 7):
1. Remove cover and place it in a location that allows it to
sense the room temperature.
NOTE: Allow several minutes for the thermometer to stop
being affected by the heat from your hand.
2. Rotate the setpoint knob counterclockwise until you
hear the switch click.
3. Hold the setpoint knob firmly and rotate the setpoint
scale ring counterclockwise until 12 o’clock on the ring
is aligned with the thermometer cover.
4. The heat from your hand will affect the diaphragm sen-
sor so wait five minutes and verify the calibration.
10
8
6
0
1000
F
2000
ELEVATION IN FEET
SEA
LEVEL
3000
4000
5000
6000
4
2
0
LOS ANGELES
ATLANTA
LAS VEGAS
DENVER
M20353
101
99
95
93
89
0.4
KPa
ELEVATION
CITIES WITH
TEMPERATURE
CORRECTIONS
( C CORRECTIONS
TO BE ADDED)
INCREASING
B
A
R
OMETRIC PRESSURE
ELEVATION IN METERS
1.2 2.0 2.8 3.6 4.4 5.2 6.0
M20354
(SEA LEVEL)
WINNIPEG
CALGARY
0
240M
574M
677M
1079M
(FOR EXAMPLE, A
CORRECTION OF
APPROXIMATELY 3.5 C
WOULD BE INDICATED
FOR INSTALLATION
IN CALGARY.)
REGINA
EDMONTON