Install Thermostat - Carrier 33CS Installation, Start-Up, And Operating Instructions Manual

Install Thermostat

Before installing thermostat, turn off all power to the
unit. There may be more than one power disconnect.
Electrical shock can cause injury or death.
1. Turn off all power to unit.
2. If an existing thermostat is being replaced:
a. Remove existing thermostat from the wall.
b. Disconnect wires from existing thermostat. Do not
allow wires to fall back into the wall. As each wire
is disconnected, record wire color and terminal
connection.
c. Discard or recycle old thermostat.
NOTE: Mercury is a hazardous waste and must be
disposed of properly.
3. Remove the thermostat cover from wall plate (mount-
ing base) to expose mounting holes. See Fig. 1. With the
thermostat facing forward, press the back plate on the
left hand side top corner to release the two prongs hold-
ing on the cover. Pull off the cover when the prongs have
been disengaged.
4. Route thermostat wires through large hole in mounting
base. Remove outer sheath from wires for added flex-
ibility. Standard solid or multi-conductor thermostat wire
should be used from the thermostat to the unit. Size and
length considerations are as follows: for a maximum
distance from unit of 36 ft, use 22 AWG (American
Wire Gage) wire; for a maximum distance from unit
of 100 ft, use 18 AWG wire.
5. Level mounting base against wall and mark wall through
the 2 mounting holes in base.
6. Drill two 3 ⁄ -in. mounting holes in wall where marked.
16
Be careful not to drill into wiring in wall. Electri-
cal shock could result.
Fig. 1 — Thermostat Mounting
7. Secure mounting base to wall with 2 screws and an-
chors provided. Ensure all wires exit through hole in mount-
ing base.
8. Adjust wire length and routing to allow proper closure
of the thermostat. Strip each wire at the end no more
than 1 ⁄ -in. to prevent adjacent wires from shorting to-
4
gether. Match and connect wires to terminals on the ther-
mostat. See Fig. 2-4 and Table 1.
Improper wiring or installation may cause damage
to the thermostat. Check to ensure wiring is cor-
rect before proceeding with installation of unit.
9. Push excess wiring into wall. Seal hole in wall to pre-
vent drafts.
10. Re-attach thermostat cover to back plate by aligning the
top two prongs of the back plate in the vertical groove
of the top cover and then snapping the cover onto the
back plate.
11. Turn on power to unit. The thermostat will receive power
from the unit. The thermostat will be powered by 24 v,
nominal (18 to 30 vac). Terminals R (+ 24 v), W1/O/B
(first stage heat or reversing valve), Y1 (first stage cool-
ing), and G (fan relay) will always be connected. Some
applications will use C (common), Y2 (second stage cool-
ing), or W2 (second stage heating).
W2 — Second-Stage Heat
Y2 — Second-Stage
Compressor
RS2 — Not Used
RS+5 — Not Used
RS1 — Not Used
RS GND — Not Used
Fig. 2 — Thermostat Wiring
2
LEGEND
W1/O/B — First-Stage Heat or
Reversing Valve
Y1 — First-Stage Compressor
G — Fan
W3/ECO — Third-Stage Heat or
Economizer (Not Used)
CK1 — Not Used
CK2 — Not Used
R — 24 vac Transformer
C — 24 vac Transformer
Common