Carrier 48ES---A - Manual (Page 32)

32
MOTOR
FAN GRILLE
MOTOR SHAFT
A
A08505
MAX DISTANCE BETWEEN TOP OF FAN GRILLE AND BOTTOM OF FAN BLADE
SIZE
“A”
IN. MM
24 7.3 185
30 7.3 185
36 7.3 185
42 7.6 193
48 7.6 193
60 7.6 193
Fig. 23 -- Fan Blade Position
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 panels (see Fig. 20) 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
Annually inspect all refrigerant tubing connections and the unit
base for oil accumulations. Detecting oil generally indicates a
refrigerant leak.
EXPLOSION, SAFETY AND ENVIRONMENTAL
HAZARD
Failure to follow this warning could result in personal
injury, death or property damage.
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 cooling performance is suspected,
leak--test all refrigerant tubing using an electronic leak--detector,
halide torch, or liquid--soap solution. If a refrigerant leak is
detected, refer to the Check for Refrigerant Leaks section.
If no refrigerant leaks are found and low cooling performance is
suspected, refer to the Checking and Adjusting Refrigerant Charge
section.
Gas Input
The gas input does not require checking unless improper heating
performance is suspected. If a problem exists, refer to the Start--Up
section.
Evaporator Airflow
The heating and/or 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. When necessary, refer to
the Indoor Airflow and Airflow Adjustments section to check the
system airflow.
Puron Items
Metering Device (Thermostatic Expansion Valve )
This metering device is a hard shutoff, balance port TXV. The
TXV maintains a constant superheat at the evaporator exit resulting
in higher overall system efficiency.
Pressure Switches
Pressure switches are protective devices wired into control circuit
(low voltage). They shut off compressor if abnormally high or low
pressures are present in the refrigeration circuit. These pressure
switches are specifically designed to operate with Puron (R--410A)
systems. R--22 pressure switches must not be used as replacements
for the Puron (R--410A) system.
Loss of Charge Switch
This switch is located on the liquid line and protects against low
suction pressures caused by such events as loss of charge, low
airflow across indoor coil, dirty filters, etc. It opens on a pressure
drop at about 20 psig. If system pressure is above this, switch
should be closed. To check switch:
1. Turn off all power to unit.
2. Disconnect leads on switch.
3. Apply ohm meter leads across switch. You should have
continuity on a good switch.
NOTE: Because these switches are attached to refrigeration
system under pressure, it is not advisable to remove this device for
troubleshooting unless you are reasonably certain that a problem
exists. If switch must be removed, remove and recover all system
48E
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A