69-0268—11
2
T874G,R MULTISTAGE HEAT PUMP THERMOSTATS AND Q674F,J,L SUBBASES
CAUTION
1.
Disconnect power supply to prevent electrical
shock or equipment damage.
2.
Run wires as close as possible to the
subbase. To prevent interference with the
thermostat linkage, keep wire length to a
minimum. Push excess wire back into the hole
and plug the hole to prevent drafts from
affecting the thermostat operation.
3.
Do not overtighten the thermostat captive
mounting screws because damage to the
subbase threads can result.
4.
Do not short across coil terminals on relay;
this can burn out the heat anticipator.
Location
Install the thermostat about 5 ft (1.5m) above the floor in
an area with good circulation at room temperature.
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.
Mounting the Subbase
The thermostat subbase can be mounted on a vertical
outlet box, horizontal outlet box, or directly on the wall.
M925
VERTICAL
OUTLET
BOX
ADAPTER
RING
SUBBASE
COVER
PLATE
MOUNTING
SCREWS (2)
MOUNTING
SCREWS (2)
1
SUBBASE
MOUNTING
SCREWS (2)
HORIZONTAL
OUTLET
BOX
1
2
2
NOT INCLUDED WITH UNIT.
ACCESSORY PARTS AVAILABLE (193121A).
1
2
Fig. 1. Installation of subbase on outlet box.
쐃
If you must mount the subbase on a vertical outlet
box, order part no. 193121A Adapter Assembly. See
Fig. 1. The assembly includes an adapter ring, two
screws, and a cover plate to cover marks on the
wall. Install the ring and cover plate on the vertical
outlet box.
For a wall installation, hold the subbase in position and
mark holes for the anchors. See Fig. 2. Obtain wall
anchors locally. Take care that the wires do not fall back
into the wall opening. Set aside the subbase. Drill four
3/16 in. (5 mm) holes and gently tap anchors into the
holes until flush with the wall.
WIRES THROUGH
WALL OPENING
WALL
WALL
ANCHORS
(2)
SUBBASE
MOUNTING
SCREWS (2)
M926
MOUNTING
HOLES
Fig. 2. Installation of subbase on wall.
쐇
Pull wires through the cover plate (if used) and
subbase cable opening. See Fig. 12.
쐋
Secure the cover plate (if used) and subbase with
the screws provided. Do not fully tighten the
subbase screws.
쐏
Level the subbase using a spirit level, as shown in
Fig. 11, and firmly tighten the subbase mounting
screws. The subbase mounting holes provide for
minor out-of-level adjustments.
IMPORTANT
An incorrectly leveled subbase will cause the
temperature control to deviate from setpoint.
Wiring the Subbase
All wiring must comply with local electrical codes and
ordinances. Follow the equipment manufacturer wiring
instructions when available. To wire the subbase, proceed
as follows:
쐃
Connect system wires to the subbase. See Fig. 3
through 11. A letter code is located near each
terminal for identification. The terminal barrier
permits straight or conventional wraparound wiring
connection (Fig. 13).
쐇
Firmly tighten each terminal screw.
쐋
Fit wires as close as possible to the subbase. Push
excess wire back into the hole.
쐏
Plug the hole with nonflammable insulation to
prevent drafts from affecting the thermostat.
