Honeywell T8090A User Manual
69-0750—1
4
WIRING
Follow the instructions provided by the heating, cooling
or heating-cooling equipment manufacturer. If not avail-
able, refer to the Typical Wiring Diagrams section.
able, refer to the Typical Wiring Diagrams section.
Disconnect power supply before making wiring connec-
tions to prevent electrical shock or equipment damage.
NOTE: All wiring must comply with local electrical codes
and ordinances.
This thermostat clock can be powered by 24 Vac trans-
former with battery backup, 24 Vac transformer only or
battery only, or through the control system. Refer to Figs.
16 through 19 for hookup diagrams of typical powering
applications.
battery only, or through the control system. Refer to Figs.
16 through 19 for hookup diagrams of typical powering
applications.
Wallplate (Heating-only wallplate included)
Refer to Fig. 5 and strip thermostat wire insulation as
necessary.
For heating-only systems, connect wires to R, W and C
(if applicable) terminals. See Fig. 20. Firmly tighten screws.
Push excess wire back into the wall.
Plug the hole in the wall with nonhardening caulk, putty,
Plug the hole in the wall with nonhardening caulk, putty,
or nonflammable insulation to prevent drafts from affect-
ing thermostat operation.
ing thermostat operation.
NOTE: For cooling only or heating-cooling applications,
refer to Installation Instructions packed with the wallplate
or subbase.
or subbase.
Fig. 5—Methods of connecting terminals.
MOUNT THE THERMOSTAT
Note the tabs on the top inside edge of the thermostat
base. These tabs fit the slots molded into the top of the
wallplate or subbase.
wallplate or subbase.
Hang thermostat base on wallplate or subbase.
Insert the two captive mounting screws located in the
Insert the two captive mounting screws located in the
bottom corners of the base. See Fig. 6.
Firmly tighten the screws.
Fig. 6—Thermostat mounting.
INSERT CLOCK BATTERIES
Power is supplied to the clock by the 24 Vac transformer
or two AAA alkaline batteries (included), or by the heating
or cooling control circuit. Backup batteries may be in-
stalled to supply power to the clock if power is interrupted
when using 24 Vac powering method.
or cooling control circuit. Backup batteries may be in-
stalled to supply power to the clock if power is interrupted
when using 24 Vac powering method.
Install the batteries in the thermostat. See Fig. 7.
Once a year or when batteries are dead, replace with two
Once a year or when batteries are dead, replace with two
new AAA alkaline batteries. We recommend Energizer
®
batteries.
Fig. 7—Insert clock batteries.
BARRIER
FOR WRAPAROUND
CONNECTION
STRIP 7/16 in. [11 mm]
CONNECTION
STRIP 7/16 in. [11 mm]
FOR STRAIGHT
CONNECTION
STRIP 5/16 in. [8 mm]
CONNECTION
STRIP 5/16 in. [8 mm]
M1556B
TAB (2)
MOUNTING SLOT (2)
CAPTIVE
MOUNTING SCREWS
MOUNTING SCREWS
THERMOSTAT
BASE
BASE
WALLPLATE
OR SUBBASE
OR SUBBASE
35
30
25
20
10
12
11
10
9
8
7
6
5
4
3 2
1 12
11
10
9
8
7
6
M3408
JUMPER WIRES
BATTERY LOCATION FOR
(2) AAA BATTERIES;
INSTALL WITH POSITIVE
ENDS UP
(2) AAA BATTERIES;
INSTALL WITH POSITIVE
ENDS UP
M7188