Manual

ManualsBrandsHoneywell ManualsControl panelELECTRONIC THERMOSTATS T8401C

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INSTALLATION INSTRUCTIONS

69-1483-1

T8401C

Electronic Thermostats

APPLICATION

The T8401C Thermostat provides single-stage,

nonprogrammable

temperature control for 24 Vac heating

cooling systems with manual changeover from heat to

cool. Heating cycle rate is selectable at 1, 3, 6, 9 or 12

cph. Cooling cycle reate is fixed at 3 cph. Temperature

indicature indication can be set for °F or °C.

The T8401C1031 (Fig. 1) is powered directly from the

zone panel. Batteries are not required because setpoints

are held permanently by non-volatile memory.

T8401C models include a thermostat, wallplate (for

wiring and mounting thermostat) and owner’s guide. See

Table 1 for a listing of thermostat features. See Table 2

for a listing of zone panels that can be used with the

T8401C.

Fig. 1. The T8401C1031 Thermostat.

MERCURY NOTICE

If this control is replacing a control that contains

mercury in a sealed tube, do not place your old

control in the trash. Dispose of properly.

Contact your local waste management authority

for instructions regarding recycling and the

proper disposal of an old control.

INSTALLATION

When Installing this Product…

1. Read these instructions carefully. Failure to follow

them could damage the product or cause a hazard-

ous condition.

2. Check the ratings given in the instructions and on

the product to make sure the product is suitable for

your application.

3. Installer must be a trained, experienced service

technician.

4. After installation is complete, check out product

operation as provided in these instructions.

CAUTION

Damage to Heating/Cooling System Possible.

Be careful when handling wires during

installation. Disconnect power at furnace or main

breaker/ fuse box.

Location

Install the thermostat about 5 ft (1.5m) above the floor in

an area with good air circulation at average temperature.

See Fig. 2. Do not install the thermostat where it can be

affected by:

— drafts or dead spots behind doors and in corners.

— hot or cold air from ducts.

— radiant heat from the sun or appliances.

— concealed pipes and chimneys.

— unheated (uncooled) areas such as an outside wall

behind the thermostat.

M14752

FAN SYSTEM

Auto On

Cool Off Heat

Set

Room

Table 1. Thermostat Features

Model Powering Method Changeover System Selection Fan Selection

T8401C1031 Hardwired Manual Heat-Off-Cool On-Auto

Summary of content (8 pages)

PAGE 1
T8401C Electronic Thermostats INSTALLATION INSTRUCTIONS APPLICATION The T8401C Thermostat provides single-stage, nonprogrammable temperature control for 24 Vac heating cooling systems with manual changeover from heat to cool. Heating cycle rate is selectable at 1, 3, 6, 9 or 12 cph. Cooling cycle reate is fixed at 3 cph. Temperature indicature indication can be set for °F or °C. The T8401C1031 (Fig. 1) is powered directly from the zone panel.
PAGE 2
T8401C ELECTRONIC THERMOSTATS Table 2. Zone Panel Cross Reference. TotalZone (TZ-3) T8401C1031 Yes MABS EZ (EZ-2, EZ-4) Yes Mini Zone (MM - 2, -3) One Oher Yes No Independent Zone MABS II, IIL One Yes Oher No No YES NO NO 5 FEET [1.5 METERS] NO M11338 Fig. 2. Typical location of thermostat. 5. This thermostat is a precision instrument and was carefully adjusted at the factory. Handle it carefully.
PAGE 3
T8401C ELECTRONIC THERMOSTATS Setting Fan Operation (Fuel) Switch The fan operation (fuel) switch is preset at the factory in the F position. See Fig. 4. This is the correct setting for most systems. If this system is an electric heat system, set the switch to the E position. The E setting allows the fan to turn on immediately with the heating or cooling equipment in a system where the G terminal is connected KEEP WIRING IN SHADED AREA G C .
PAGE 4
T8401C ELECTRONIC THERMOSTATS Mounting Thermostat to Wallplate 1. TOTAL ZONE MABS EZ PANEL THERMOSTAT MOTOR 2. W2 L G Y R W M6 G Y R W C M4 M1 NO CONNECTION Engage the tabs at the top of the thermostat and wallplate. Swing down the thermostat and press the lower edge of the thermostat onto the wallplate to latch. See Fig. 10. DASHED LINES INDICATE TABS ON BACK OF THERMOSTAT O B T8401 THERMOSTAT M14288 Fig. 7. T8401 with TotalZone or MABS EZ control panels (all zones) .
PAGE 5
T8401C ELECTRONIC THERMOSTATS SETTINGS AND ADJUSTMENTS Set Temperature Setpoint Setting FAN and SYSTEM Switches NOTE: NOTE: Temperature setpoint range is 40° to 99°F (5° to 37°C). Fan and system settings are controlled manually by using the switches located at the bottom of the thermostat case. See Fig. 11. The temperature setpoint and the room temperature are shown separately on the digital display.
PAGE 6
T8401C ELECTRONIC THERMOSTATS scrolling when the desired cycle rate is displayed. See Table 3 for the cycle rate options and the corresponding system equipment. Optional System Checkout When in steps 2 and 3 only, the ▼ key can be used to turn heat or cool outputs on and off. Change the SYSTEM switch setting to test heat or cool outputs. No action takes place If the SYSTEM switch is in the Off position.
PAGE 7
T8401C ELECTRONIC THERMOSTATS Cooling 1. NOTE: To bypass the 5 minute delay, see optional system checkout on page 6. 2. CAUTION 3. Low Temperature Hazard. Operating at too low of an outdoor temperature may cause compressor damage. Do not operate cooling if outdoor temperature is below 50°F (10°C). Refer to equipment manufacturer instructions. Slide the SYSTEM switch to Cool and the FAN switch to Auto. Press the ▼ key to lower the temperature setting several degrees below the room temperature.
PAGE 8
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