Setting And Checkout - Honeywell T4800A/CT1750A Manual

95C-10690B-2 4/28/00 9:53 PM
T4800A/CT1750A ELECTRIC HEATING THERMOSTAT
When replacing an old line voltage electric heating
thermostat, remove the old thermostat carefully to avoid
damage to the insulation on wiring.
Check the old insulation for cracks, nicks or fraying and
apply quality plastic electrical tape where necessary to achieve
adequate insulation, or replace the wires in an approved fash-
ion.
CAUTION
!
• Disconnect power supply before making wiring
connections to prevent electrical shock or equipment
damage.
• All wiring must comply with applicable codes and
ordinances.
• Thermostats are designed to be used with appliances
having a limit control.
Wiring:
1. Carefully remove cover by gently lifting at edge with a
slot screwdriver.
2. Attach wires with appropriate solderless connectors –
take care not to cross 240V wires.
3. Secure thermostat to the electrical box with captive
mounting screws (hint: rotate control knob to more
easily access lower mounting screw).
NOTE: Handle thermostat with care. Excessive pressure
could damage the control knob or sensing element.
4. Snap cover in place.
Fig. 2 – Typical hookup for T4800A/CT1750 thermostat
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD
1
PROTECTION AS REQUIRED.
2
SPECIAL SERVICE CO/ALR SOLDERLESS CONNECTORS MUST BE
USED WHEN CONNECTING ALUMINUM CONDUCTORS; OTHER-
WISE A FIRE HAZARD MAY RESULT.
3
BREAKS HEATING CIRCUIT ON TEMPERATURE RISE.
THERMOSTAT IS DESIGNED TO BE USED WITH APPLIANCES
4
EQUIPPED WITH A LIMIT CONTROL.
Home and Building Control
Honeywell Inc.
1985 Douglas Drive North
Golden Valley, MN
55422
Page 3
T4800A/CT1750
3
Electronic
Line Voltage
Thermostat
Black Black
2
L1
Electric
(Hot)
Resistance
1 Heating
Appliance
L2
To connect wires:
Make line voltage wiring connections directly to the
leadwires installed on the thermostat, using wire
connectors approved for size and number of wires
to be connected.
Important: Be sure that all wire connectors are tight.
Installation Hint! After attaching the solderless connec-
tors, pre-bend and push the solid conductors back into
the electrical box, then secure the thermostat with
the mounting screws.
NOTE: When using aluminum conductors all wiring con-
nections to this thermostat must be made to the factory
installed leadwires, using approved CO/ALR solderless
connectors.
CAUTION: This thermostat contains no field-serviceable
parts.

SETTING AND CHECKOUT

After the thermostat has been installed and powered up,
simulate normal operations as follows:
1. Turn setting dial all the way clockwise.
LED lights and electric heater should start to
warm up.
2. Turn dial all the way counterclockwise.
LED goes off, the power circuit should be broken and
electric heater should start to cool.
NOTE: The T4800/CT1750 has a "load-responsive time
delay" to reduce equipment wear which makes the
mechanical switching differential appear wider the faster
the knob is rotated. This time delay does not affect the
thermal operation of the T4800/CT1750.
3. To determine the final setting, begin with the dial
indicator at 20°C (68°F) on the scale. Let the room
warm up (or cool down) until the heaters start to
cycle. If this setting is not satisfactory after an hour
of stable operation, turn the indicator upscale to raise
the temperature, or downscale to lower it. Move the
indicator only one degree Celsius (two degrees
Fahrenheit) at a time.
4
Once set, T4800/CT1750 does not need to be adjusted for
comfort during the heating season.
REMINDER: The T4800/CT1750 can improve comfort and
reduce heating costs when set lower than a conventional
electric heat thermostat.
The development of this technology was assisted by the
electric power industry of the United States under the
sponsorship of EPRI, the Electric Power Research
Institute.
INSTALLATION • CHECKOUT