Step 7
−
Make Connections to the Outdoor Unit
COOLING-ONLY SYSTEMS
−
To connect the 38HDC or
HDS condensing unit to the fan coil unit(s) so that the sys-
tem will operate correctly:
Route 2 field-supplied wires of 18-gage AWG (American
Wire Gage) thermostat cable between the low-voltage ter-
minal block of the fan coil unit (TB2) and the 38HDC or
HDS unit low-voltage terminal block. Connect the wires be-
tween terminals Y and Y and between terminals C and C.
HEAT PUMP SYSTEMS
−
To connect the 38BK heat pump
unit to the fan coil unit so that the system will operate
correctly:
IMPORTANT: DO NOT RUN THE THERMISTOR
CABLE IN THE SAME CONDUIT AS THE POWER
WIRING.
1. One thermistor connection cord with a lead length of
24 ft is shipped with the 40QNE fan coil unit. Run the
connection cord from the low-voltage terminal board in
the control box in the fan coil unit (TB3) to the heat pump
unit. Route the wire carefully so that it will not be
damaged.
2. For cooling operation, route 2 field-supplied wires of
18-gage AWG (American Wire Gage) thermostat cable
between the low-voltage terminal block of the fan coil
unit (TB2) and the 38BK unit low-voltage terminal block.
Connect the wires between terminals Y and Y and be-
tween terminals C and C.
3. For heating operation, route 3 additional wires of
18-gage AWG thermostat cable between the low-voltage
terminal block of the fan coil unit (TB2) and the 38BK
unit low-voltage terminal block. Connect the wires be-
tween terminals R and R, O and O, and G and G.
Step 8
−
Install Fan Coil Unit Onto Mounting
Bracket
1. Hook the fan coil unit onto the top of the mounting bracket.
See Fig. 16.
2. Snap the fan coil unit onto the mounting bracket as shown
in Fig. 16.
IMPORTANT: An audible snapping sound will be
heard as the hook on the unit is secured into the
hole on the mounting bracket. Be sure unit is cor-
rectly mounted.
START-UP
Complete the following checks and the Start-Up Check-
list on page CL-1 before system start-up. Refer to outdoor
unit installation, start-up and service instructions for system
start-up procedures and refrigerant charging methods.
1. Check condensate drainage system.
Add water to check the drainage flow. If water does not
flow regularly, check the pipe slope or see if there are
any pipe restrictions.
2. Make sure that all wiring connections are correct and
tight.
3. Make sure that all barriers, covers, and panels are in place.
4. Ensure that the filters have been installed and that the
discharge louvers are correctly positioned.
Never operate unit without a filter. Damage to the
unit or personal injury may result.
5. If the unit is equipped with a crankcase heater, energize
a minimum of 24 hours before starting the unit. To en-
ergize crankcase heater only, close indoor unit discon-
nect, then with the remote controller, set unit in off mode
and close the outdoor unit disconnect.
6. Fully backseat (open) the liquid and vapor tube service
valves.
7. Unit is shipped with valve stems frontseated and caps
factory installed. Replace stem caps after system is opened
to refrigerant flow (backseated). Replace caps finger tight.
Fig. 15 — High Voltage Connections
Fig. 16 — Mounting Unit to Bracket
9
