Honeywell T8624D User Manual

T8624D Chronotherm

®

Deluxe Zone

Multistage Thermostat

INSTALLATION INSTRUCTIONS

APPLICATION

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

Table 1. Description of T8624 Thermostats.

Model Application Powering Method Changeover System Selection Fan Selection

T8624D Zone 1 on MABS II or

TotalZone® system

Requires common wire
to power supply

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

Automatic or

manual

Heat-Off-Cool-Auto On-Auto

IV

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.

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

X-XX UL

69-1074

T8624D CHRONOTHERM

®

IV DELUXE ZONE MULTISTAGE THERMOSTAT

WALL
ANCHORS
(2)

NO

WIRES
THROUGH WALL

YES

NO

5 FEET

[1.5 METERS]

Fig. 1. Typical location of thermostat.

 Position the wallplate over the holes, pulling wires

WALL

 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.

NO

M10106

through the wiring opening.

MOUNTING
HOLES

MOUNTING
SCREWS

Fig. 2. Mounting the wallplate.

 Use a pencil to mark the mounting holes. See Fig. 2.

 Remove the wallplate from the wall and drill two

3/16 inch holes in the wall (if drywall) as marked.
For firmer material such as plaster, drill two
7/32 inch holes. Gently tap anchors (provided) into
the drilled holes until flush with the wall.

69-1074

M15044

CAUTION

Disconnect power before wiring to prevent
electrical shock or equipment damage.

 Loosen the terminal screws on the wallplate and

connect the system wires. See Fig. 5.

IMPORTANT

Use 18 gauge, color-coded thermostat cable for
proper wiring.

 Securely tighten each terminal screw.

 Push excess wire back into the hole.

 Plug the hole with nonflammable insulation to

prevent drafts from affecting the thermostat.

2

T8624D CHRONOTHERM

C7089B OUTDOOR

TEMPERATURE

SENSOR (OPTIONAL)

OG

NOTE:

Fig. 3. Typical wiring diagram for T8624 on zone 1

CHANGEOVER
CONTROL

THERMOSTAT

BCY1RW1W2Y2OTOT

ZONE 1

W2

TotalZone®
PANEL

L

THERMOSTAT
CONNECTIONS

G

Y

R

W

M6

M4

M1

WHEN USING W2 ON THE THERMOSTAT TO CONTROL THE
SECOND STAGE OF HEATING, MAKE SURE THE STAGE
JUMPER IS IN PLACE, ON THE TZ PANEL

TotalZone® control panel.

C7089B OUTDOOR

TEMPERATURE

SENSOR (OPTIONAL)

OG

O1

G1

B1

E1

THERMOSTAT

BCW1RY1W2Y2OTOT

ZONE 1

T8

T7

T6

T5

T4

M11418

®

IV DELUXE ZONE MULTISTAGE THERMOSTAT

Mounting Thermostat

 Engage tabs at the top of the thermostat and

wallplate. See Fig. 6. 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 thermo­stat; remove top last.

A.

ENGAGE TABS AT TOP OF THERMOSTAT AND WALLPLATE.

B.

PRESS LOWER EDGE OF CASE TO LATCH.

M15043

Fig. 6. Mounting thermostat on wallplate.

M1

MABS II/L
PANEL
THERMOSTAT
CONNECTIONS

Fig. 4. Typical wiring diagram for T8624D on zone 1

MABS II control panel.

FOR WRAPAROUND
INSERTION STRIP
7/16 IN. (11 MM).

FOR STRAIGHT
INSERTION STRIP
5/16 IN. (8 MM).

M11419

M4826

Fig. 5. Proper wiring technique.

3

69-1074

T8624D CHRONOTHERM

®

IV DELUXE ZONE MULTISTAGE THERMOSTAT

SET WAKE TIMES
AND SETPOINTS

INCREASE TIME SETTING
OR SCROLL FORWARD
THROUGH INSTALLER
SETUP AND SELF-TEST

SET CURRENT
DAY AND TIME

RETURN TO
NORMAL
OPERATIONS

ENTER
INDEFINITE
OR TIMED
HOLD MODE

SET CURRENT OR
PROGRAM DAY

CHANGE BETWEEN
DAYLIGHT SAVINGS
AND STANDARD TIME

COPY ONE PROGRAMMED
DAY TO ANOTHER DAY

Run

Program

Hold Temp

Set Current

Time Set Program

Day/Time

Day

Daylight

Copy

Time

Fig. 7. T8624D key locations and descriptions.

Using Thermostat Keys

The thermostat keys are used to:

• set current day and time,

•program times and setpoints for heating and cooling,

•temporarily override program temperatures,

•display present setting,

• configure Installer Setup,

• check Self-Test,

•display outdoor temperature (select models),

• set the system operation,

• set the fan operation.

See Fig. 7 for the location of the keys.

SETTINGS

System and Fan Settings

The system default setting is Heat and the fan default
setting is Auto. Use the System and Fan keys to change
the settings. See Fig. 8. The fan settings can be set for
each program period individually. The system selection is
for all the program periods.

System settings control the thermostat operation as
follows:

Heat: The thermostat controls the heating.
Off: Both the heating and cooling are off.

INCREASE TEMPERATURE

Leave

Wake

Heat/Cool

Settings

SETTING OR SCROLL
FORWARD THROUGH
INSTALLER SETUP OPTIONS

DECREASE TEMPERATURE
SETTING OR SCROLL
BACKWARD THROUGH
INSTALLER SETUP OPTIONS

DISPLAY INFORMATION
SUCH AS PRESENT
SETTINGS AND OUTDOOR
TEMPERATURE

SELECT FAN
OPERATION

SELECT SYSTEM
OPERATION

Return

System Fan

SET LEAVE TIMES
AND SETPOINTS

SET RETURN TIMES
AND SETPOINTS

Leave

Wake

Heat/Cool

Settings

DECREASE TIME SETTING
OR SCROLL BACKWARD
THROUGH INSTALLER
SETUP AND SELF-TEST

Fan settings control the system fan as follows:

Return Sleep

System Fan

CHANGE BETWEEN
HEATING AND COOLING
SETPOINTS

Cool: The thermostat controls the cooling.
Auto: The thermostat automatically changes between

heating and cooling operation, depending on the
indoor temperature.

On: Fan operates continuously.
Auto: Fan operates with equipment.

Time Set Program

Run

Set Current

Program

Day/Time

Hold Temp

Day

Daylight

Copy

Time

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.

SET SLEEP
TIMES AND
SETPOINTS

M10405

Sleep

M15042

System

Fan

69-1074

4