PRE-START-UP
!WARNING
ENVIRONMENTAL, FIRE, EXPLOSION, ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury or death and/or property damage.
1.Follow recognized safety practices and wear protective goggles when checking or servicing refrigerant system.
2.Relieve and recover all refrigerant from system before touching or disturbing compressor plug if refrigerant leak is suspected around compressor terminals.
3.Never attempt to repair soldered connection while refrigerant system is under pressure.
4.Do not use torch to remove any component. System contains oil and refrigerant under pressure.
5.To remove a component, wear protective goggles and proceed as follows:
a.Shut off electrical power to unit and install lockout tag.
b.Relieve and reclaim all refrigerant from system using both high- and low-pressure ports.
c.Cut component connecting tubing with tubing cutter and remove component from unit.
d.Carefully unsweat remaining tubing stubs when necessary. Oil can ignite when exposed to torch flame.
Proceed as follows to inspect and prepare the unit for initial start-up:
1.Remove all access panels (see Fig. 17).
2.Read and follow instructions on all DANGER, WARNING, CAUTION, and INFORMATION labels attached to, or shipped with unit.
3.Make the following inspections:
a.Inspect for shipping and handling damages, such as broken lines, loose parts, disconnected wires, etc.
b.Inspect for oil at all refrigerant tubing connections and on unit base. Detecting oil generally indicates a refrigerant leak. Leak test all refrigerant tubing connections using electronic leak detector, or liquid-soap solution. If a refrigerant leak is detected, see following Check for Refrigerant Leaks section.
c.Inspect all field- and factory-wiring connections. Be sure that connections are completed and tight.
d.Ensure wires do not touch refrigerant tubing or sharp sheet metal edges.
e.Inspect coil fins. If damaged during shipping and handling, carefully straighten fins with a fin comb.
4.Verify the following conditions:
a.Make sure that condensate drain pan and trap are filled with water to ensure proper drainage.
b.Make sure that all tools and miscellaneous loose parts have been removed.
START-UP
Step 1 — Check for Refrigerant Leaks
Proceed as follows to locate and repair a refrigerant leak and to charge the unit:
1.Locate leak and make sure that refrigerant system pressure has been relieved and reclaimed from both high- and low-pressure ports.
2. Repair leak following accepted practices.
NOTE: Install a filter drier whenever the system has been opened for repair.
3.Add a small charge of Puron (R-410A) refrigerant vapor to system and leak-test unit.
4.Recover refrigerant from system and evacuate to 500 microns if no additional leaks are found.
5.Charge unit with Puron (R-410A) refrigerant, using an accurate scale. Refer to unit rating plate for required charge.
Step 2 — Start-Up Cooling Section And Make Adjustments
Complete the required procedures given in the Pre-Start-Up section before starting the unit. Do not jumper any safety devices when operating the unit. Do not operate the unit when the outdoor temperature is below 40°F (4°C) (unless accessory low-ambient kit is installed). Do not rapid cycle the compressor. Allow 5 minutes between “on” cycles to prevent compressor damage.
CHECKING COOLING CONTROL OPERATION
Start and check the unit for proper cooling control operation as follows:
1.Place room thermostat SYSTEM switch in OFF position. Observe that blower motor starts when FAN switch is placed in ON position and shuts down when FAN switch is placed in AUTO position.
2.Place SYSTEM switch in COOL position and FAN switch in AUTO position. Set cooling control below room temperature. Observe that compressor, condenser fan, and evaporator blower motors start. Observe that compressor and outdoor fan shut down when control setting is satisfied and that indoor blower shuts down after 90 second fan time delay expires.
IMPORTANT: Three-phase, scroll compressors are direction oriented. Unit must be checked to ensure proper compressor 3-phase power lead orientation. If not corrected within 5 minutes, the internal protector will shut off the compressor. The 3-phase power leads to the unit must be reversed to correct rotation. When turning backwards, the difference between compressor suction and discharge pressures may be minimal.
CHECKING AND ADJUSTING REFRIGERANT CHARGE
The refrigerant system is fully charged with Puron (R-410A) refrigerant and is tested and factory sealed.
NOTE: Adjustment of the refrigerant charge is not required unless the unit is suspected of not having the proper Puron (R-410A) charge.
A subcooling charging chart is attached to the inside of the compressor access panel (see Fig. 17). The chart includes the required liquid line temperature at given discharge line pressures and outdoor ambient temperatures.
An accurate thermocouple- or thermistor-type thermometer, and a gauge manifold are required when using the subcooling charging method for evaluating the unit charge. Do not use mercury or small dial-type thermometers because they are not adequate for this type of measurement.
NOTE: Allow system to operate for a minimum of 15 minutes before checking or adjusting refrigerant charge.
IMPORTANT: When evaluating the refrigerant charge, an indicated adjustment to the specified factory charge must always be very minimal. If a substantial adjustment is indicated, an abnormal condition exists somewhere in the cooling system, such as insufficient airflow across either coil or both coils.
