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X-XX UL

INSTALLATION INSTRUCTIONS

®U.S. Registered Trademark
Copyright © 1997 Honeywell Inc.  •            •   All Rights Reserved

T8624D Chronotherm

®

 IV

Deluxe Zone

Multistage Thermostat

APPLICATION

The T8624D Chronotherm® IV Deluxe ZoneMultistage
Thermostat provides electronic control of 24 Vac
multistage zoned heating and cooling system. Refer to

Table 1 for a general description of the thermostat.
The T8624 thermostat requires a common wire to
supply power.

Table 1. Description of T8624 Thermostats.

RECYCLING NOTICE

If this control is replacing a control that contains
mercury in a sealed tube, do not place your old
control in the trash.

Contact your local waste management authority for
instructions regarding recycling and the proper
disposal of the old thermostat.

INSTALLATION

When Installing this Product...

1. Read these instructions carefully. Failure to follow

the instructions can damage the product or cause a
hazardous 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 completing installation, use these instructions

to check out the product operation.

Location

Install the thermostat about 5 ft (1.5m) above the floor in
an area with good air circulation at average temperature.
See Fig. 1.

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 sun or appliances.

concealed pipes and chimneys.

unheated (uncooled) areas such as an outside wall
behind the thermostat.

Wallplate Installation

The thermostat can be mounted horizontally on the wall or
on a 2 in. x 4 in. wiring box. Position wallplate horizontally
on the wall or on a 2 in. x 4 in. wiring box.

Position and level the wallplate (for appearance
only). The thermostat will function properly even
when not level.

Model

Application

Powering Method

Changeover

System Selection

Fan Selection

T8624D

Zone 1 on MABS II or
TotalZone® system

Requires common wire
to power supply

Automatic or

manual

Heat-Off-Cool-Auto

On-Auto

69-1074

Summary of Contents for CHRONOTERM IV T8624D

Page 1: ...tructions 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 completing installation use these instructions to check out the product operation Location Install the thermostat about 5 ft 1 5m above the floor in an area with good air circulation at average temperature See Fig 1 Do not install the thermosta...

Page 2: ...ng Loosely insert the mounting screws into the holes Tighten mounting screws WIRING All wiring must comply with local electrical codes and ordinances Refer to Fig 3 and 4 for typical hookups A letter code is located near each terminal for identification CAUTION Disconnect power before wiring to prevent electrical shock or equipment damage Loosen the terminal screws on the wallplate and connect the...

Page 3: ...Be sure to align the subbase pins to avoid damage to the thermostat Press lower edge of case to close and latch NOTE To remove the thermostat from the wall first pull out at the bottom of the thermo stat remove top last Fig 5 Proper wiring technique O G B C Y1 R W1 W2 Y2 OT OT W2 L G Y R W M6 M4 M1 THERMOSTAT ZONE 1 M11418 TotalZone PANEL THERMOSTAT CONNECTIONS WHEN USING W2 ON THE THERMOSTAT TO C...

Page 4: ...ing Off Both the heating and cooling are off Fig 8 T8624D System and Fan key locations NOTE Always press the keys with your fingertip or similar blunt tool Sharp instruments like a pen or pencil point can damage the keyboard M15042 Hold Temp Run Program Copy Daylight Time Set Current Day Time System Fan Time Set Program Day System Fan Wake Leave Return Sleep Heat Cool Settings M10405 Time Set Prog...

Page 5: ...Em Ht M10349 INSTALLER SETUP NUMBER DISPLAY COLUMN 2 OF TABLE 3 FACTORY SETTING OR OTHER CHOICE DISPLAY COLUMN 3 OR 5 OF TABLE 3 Fig 10 Display of Installer Setup number and setting IMPORTANT Only configurable numbers are shown on the device Example If thermostat does not have a system key Installer Setup Number 12 will not be displayed Review Table 3 factory settings and mark any desired changes ...

Page 6: ...aptive Intelligent Recovery control is activated system starts early so setpoint is reached by start of program period 1 Conventional recovery system starts recovery at programmed time Degree tempera ture display 14 0 Temperature is displayed in F 1 Temperature is displayed in C Not used 15 Clock format 16 0 12 hour clock format 1 24 hour clock format Not used 17 and 18 Extended fan operation in h...

Page 7: ...eat Cool Settings Daylight Time Copy PM Tue Set Day Time Installer Setup Number Press Time key to Factory Setting Other Choices Press or key to change Actual Select change Display Description Display Description Setting Minimum off time for the compressor 33 5 5 minute minimum off time for the compressor 0 thru 4 Minimum number of minutes 0 thru 5 the compressor will be off between calls for the c...

Page 8: ...same time until 10 appears All segments of the display will be displayed before the 10 appears See Fig 11 and 12 M10316 Time Set Program System Fan Run Program Run Program Hold Temp Set Current Day Time Wake Leave Return Sleep Day Heat Cool Settings Daylight Time Copy Auto System Fan Wake Room AM DST Tue Heat Fig 11 Display of all the segments of the LCD Aux Ht Heat Auto System Fan Off Auto Wake M...

Page 9: ...ge one heat comes on The system fan is also energized 12 Stage two heat comes on Stage one heat and system fan remain on 11 Stage two heat turns off 10 Stage one heat and system fan turn off Cooling Equipment Self Test Time 30 Change from heating to cooling equipment self test 31 Stage one cool and system fan come on 32 Stage two cool comes on Stage one cool and system fan remain on 31 Stage two c...

Page 10: ...r to soak in the outdoor air for a minimum of five minutes before taking a reading TROUBLESHOOTING GUIDE Continued Symptom Possible Cause Action Display will not come on Thermostat is not being powered Check for 24 Vac between R and C terminals If missing 24 Vac check if the circuit breaker is tripped reset the circuit breaker check if the system fuse is blown replace the fuse check if the power s...

Page 11: ...et heating setpoint to desired temperature Cooling will not come on No power to the thermostat Check for 24 Vac between R and C If missing 24 Vac check if the circuit breaker is tripped reset the circuit breaker check if the system fuse is blown replace the fuse check if the power switch on the HVAC equipment is in the Off position set to the On position check wiring between thermostat and zone co...

Page 12: ...69 1074 12 T8624D CHRONOTHERM IV DELUXE ZONE MULTISTAGE THERMOSTAT 69 1074 J H 3 97 Printed in Taiwan R O C 57 Bushes Lane Elmwood Park NJ 07407 3204 www honeywell com yourhome ...

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