17
5. When replacing fan blade, position blade so that the
hub is 1/8 in. (3mm) away from the motor end (1/8 in.
(3mm) of motor shaft will be visible) (See Fig. 12).
6. Ensure that setscrew engages the flat area on the
motor shaft when tightening.
7. Replace grille.
ELECTRICAL CONTROLS AND WIRING
Inspect and check the electrical controls and wiring
annually. Be sure to turn off the electrical power to the unit.
Remove access panel to locate all the electrical controls
and wiring. Check all electrical connections for tightness.
Tighten all screw connections. If any smoky or burned
connections are noticed, disassemble the connection,
clean all the parts, re--strip the wire end and reassemble the
connection properly and securely.
After inspecting the electrical controls and wiring, replace
all the panels. Start the unit, and observe at least one
complete cooling cycle to ensure proper operation. If
discrepancies are observed in operating cycle, or if a
suspected malfunction has occurred, check each electrical
component with the proper electrical instrumentation. Refer
to the unit wiring label when making these checks.
REFRIGERANT CIRCUIT
Inspect all refrigerant tubing connections and the unit base
for oil accumulation annually. Detecting oil generally
indicates a refrigerant leak.
EXPLOSION, PERSONAL INJURY, EVIRONMENTAL
HAZARD
Failure to follow this warning could result in property
damage, personal injury or death.
System under pressure. Relieve pressure and recover
all refrigerant before system repair or final unit disposal.
Use all service ports and open all flow--control devices,
including solenoid valves.
!
WARNING
If oil is detected or if low performance is suspected, leak test
all refrigerant tubing using an electronic leak detector, or
liquid--soap solution. If a refrigerant leak is detected, refer
to Check for Refrigerant Leaks section.
If no refrigerant leaks are found and low performance is
suspected, refer to
Checking and Adjusting Refrigerant
Charge
section.
INDOOR AIRFLOW
The cooling airflow does not require checking unless
improper performance is suspected. If a problem exists, be
sure that all supply-- and return--air grilles are open and free
from obstructions, and that the air filter is clean.
METERING DEVICES--PISTON
Refrigerant metering device is a fixed orifice and is located
in the distributor assembly to the indoor coil.
There is a liquid header with a brass distributor and feeder
tube going into outdoor coil. At the end of one of the feeder
tubes, there is a 3/8--in. OD stub tube approximately 3 in.
long (see Fig. 21). The defrost thermostat should be located
on this stub tube. Note that there is only one stub tube used
with liquid header, and on most units it is the bottom circuit.
TROUBLESHOOTING
Refer to the Troubleshooting Chart (Table 9) for
troubleshooting information.
START--UP CHECKLIST
Use the Start--Up Checklist at the back of this manual.