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After inspecting the electrical controls and wiring, replace the
access panels (see Fig. 17). 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
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.
WARNING
!
EXPLOSION, SAFETY AND ENVIRONMENTAL
HAZARD
Failure to follow this warning could result in personal
injury, death or equipment damage.
This system uses Puron (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
Puron. If you are unsure, consult the equipment
manufacturer.
If low cooling 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 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.
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.
Puron Items
The indoor metering device is either a TXV or orifice type device
depending on size.
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 Puron
(R- -410A) systems. R- -22 pressure switches must not be used as
replacements for the Puron (R- -410A) air conditioner.
Low Pressure Switch (24 size 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 at 50 psig
(957 Pa). 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 ohmmeter leads across switch. You should have
continuity on a closed 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
with
the
proper
electrical
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.
Compressor (Puron Refrigerant)
The compressor used in this product is specifically designed to
operate with Puron (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.
For models that have a scroll compressor, the 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 Puron (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
Puron. If you are unsure, consult the equipment
manufacturer.
This system uses Puron (R- -410A) refrigerant which has higher
operating pressures than R- -22 and other refrigerants. No other
refrigerant may be used in this system. Gage set, hoses, and
recovery system must be designed to handle Puron. If you are
unsure, consult the equipment manufacturer. Failure to use Puron
compatible servicing equipment or replacement components may
result in property damage or injury.
31
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