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for tightness. Tighten all screw connections. If any smoky or
burned connections are noticed, disassemble the connection,
clean all the parts, restrip the wire end and reassemble the
connection properly and securely.
After inspecting the electrical controls and wiring, replace the
access panels (see Figure 16). Start the unit, and observe at
least one complete heating cycle and one complete cooling
cycle to ensure proper operation. If discrepancies are observed
in either or both operating cycles, 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 checkouts.
NOTE:
Refer to the heating and/or cooling sequence of
operation in this publication as an aid in determining proper
control operation
Refrigerant Circuit
Inspect all refrigerant tubing connections and the unit base for
oil accumulations annually. Detecting oil generally indicates a
refrigerant leak.
WARNING
!
EXPLOSION, SAFETY AND ENVIRONMENTAL
HAZARD
Failure to follow this warning could result in personal
injury, death or equipment damage.
This system uses R--410A refrigerant which has
higher operating pressures than R--22 and other
refrigerants. No other refrigerant may be used in this
system. Gauge set, hoses, and recovery system
must be designed to handle R--410A. If you are
unsure, consult the equipment manufacturer.
If oil is detected or if low cooling performance is suspected,
leak--test
all
refrigerant
leak--detector, halide torch, 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 cooling performance is
suspected, refer to Checking and Adjusting Refrigerant Charge
section.
Evaporator Airflow
The heating and/or cooling air--flow 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 Indoor Airflow and Airflow Adjustments
section to check the system airflow.
R- - 410A Items
The indoor metering device is a TXV type device.
Pressure Switches
Pressure switches are protective devices wired into the 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 R--410A systems. R--22 pressure switches must not be
used as replacements for the R--410A air conditioner.
Low- -Pressure Switch (Air Conditioner
Only)
This switch is located on the suction 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 50 psig
pressure is above this, switch should be closed.
24
tubing
using
an
electronic
(957 Pa). If system
Specifications subject to change without notice.
To check switch:
1. Turn off all power to unit.
2. Disconnect leads on switch.
3. Apply ohmmeter 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 charge so that pressure gauges read 0 psi (0 Pa).
Never open system without breaking vacuum with dry nitrogen.
High- - Pressure Switch
The high--pressure switch is located in the discharge line and
protects against excessive condenser coil pressure. It opens at
650 psig (31.1 kPa). High pressure may be caused by a dirty
condenser coil, failed fan motor, or condenser air recirculation.
To check switch:
1. Turn off all power to unit.
2. Disconnect leads on switch.
3. Apply ohmmeter leads across switch. You should have
continuity on a good switch.
Copeland Scroll Compressor (R- -410A
Refrigerant)
The compressor used in this product is specifically designed to
operate with R--410A refrigerant and cannot be interchanged.
The compressor is an electrical (as well as mechanical) device.
Exercise extreme caution when working near compressors.
Power should be shut off, if possible, for most troubleshooting
techniques. Refrigerants present additional safety hazards.
WARNING
!
FIRE/EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury or death and/or property damage.
Wear safety glasses and gloves when handling
refrigerants. Keep torches and other ignition sources
away from refrigerants and oils.
The scroll compressor pumps refrigerant throughout the system
by the interaction of a stationary and an orbiting scroll. The
scroll compressor has no dynamic suction or discharge valves,
and it is more tolerant of stresses caused by debris, liquid
slugging, and flooded starts. The compressor is equipped with
a noise reducing shutdown device and an internal pressure
relief port. The pressure relief port is a safety device, designed
to protect against extreme high pressure. The relief port has an
operating range between 550 (26.3 kPa) and 625 (29.9 kPa)
psig differential pressure.
Refrigerant
WARNING
!
EXPLOSION, ENVIRONMENTAL HAZARD
Failure to follow this warning could result in personal
injury, death or equipment damage.
This system uses R--410A refrigerant which has
higher operating pressures than R--22 and other
refrigerants. No other refrigerant may be used in this
system. Gauge set, hoses, and recovery system
must be designed to handle R--410A. If you are
unsure, consult the equipment manufacturer.
51901190402
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