Unit Preparation, Return-Air Filters, Cooling

50HE,HJ

PRE-START-UP

!WARNING

FIRE, EXPLOSION, ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal injury, death, and/or property damage.

1.Follow recognized safety practices and wear protective goggles when checking or servicing a refrigerant system.

2.Do not operate the compressor or provide any electric power to the unit unless the compressor terminal cover is in place and secured.

3.Do not remove the compressor terminal cover until all electrical sources are disconnected and tagged with lockout tags.

4.Relieve all pressure from the system before touching or disturbing anything inside the terminal box if a refrigerant leak is suspected around the compressor terminals. Use accepted methods to recover the refrigerant.

5.Never attempt to repair a soldered connection while the refrigerant system is under pressure.

6.Do not use a torch to remove any component. The system contains oil and refrigerant under pressure. To remove a component, wear protective goggles and proceed as follows:

a.Shut off electrical power to the unit and tag disconnect.

b.Recover refrigerant to relieve all pressure

from the system using both high-pressure and low-pressure ports.

c. Cut component connection tubing with a tubing cutter, and remove the component from the unit.

d. Carefully unsweat the remaining tubing stubs when necessary. Oil can ignite when exposed to a torch flame.

Proceed as follows to inspect and prepare the unit for initial start-up:

1.Remove all access panels.

2.Read and follow instructions on all 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, or 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, halide torch, or liquid-soap solution.

c.Inspect all field-wiring and factory-wiring connections. Be sure that connections are completed and tight. Be sure that wires are not in contact with refrigerant tubing or sharp edges.

d.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 condenser-fan blade are correctly positioned in fan orifice. See Condenser-Fan Adjustment section for more details.

b.Make sure that air filter(s) is in place.

c.Make sure that condensate drain trap is filled with water to ensure proper drainage.

d. Make sure that all tools and miscellaneous loose parts have been removed.

START-UP

Step 1 —Unit Preparation

Make sure that the unit has been installed in accordance with installation instructions and applicable codes.

Step 2 —Return-Air Filters

Make sure the correct filters are installed in the unit (See Table 1). Do not operate the unit without return-air filters.

Step 3 —Outdoor-Air Inlet Screens

Outdoor-air inlet screen(s) must be in place before operating the unit.

Step 4 —Compressor Mounting

Compressors are internally spring mounted. Do not loosen or remove the compressor holddown bolts.

Step 5 —Internal Wiring

Check all electrical connections in unit control boxes; tighten them as required.

Step 6 —Refrigerant Service Ports

Each unit system has 4 Schrader-type service ports: one on the suction line, one on the liquid line, and 2 on the compressor discharge line. Be sure that caps on the ports are tight.

Step 7 —High Flow Valves

Two high flow refrigerant valves are located on the hot gas tube coming out of the compressor and the suction tubes. Large black plastic caps distinguish these valves with O-rings located inside the caps. No field access to these valves is available at this time. Ensure the plastic caps are in place and tight or the possibility of refrigerant leakage could occur.

Step 8 —Compressor Rotation

On 3-phase units be certain that the compressor is rotating in the proper direction. To determine whether or not compressor is rotating in the proper direction:

1.Connect the service gauges to suction and discharge pressure fittings.

2.Energize the compressor.

3.The suction pressure should drop and the discharge pressure should rise, as is normal on any start-up.

If the suction pressure does not drop and the discharge pressure does not rise to normal levels:

1.Note that the indoor fan (006 and 007 three-phase units only) is probably also rotating in the wrong direction.

2.Turn off power to the unit and tag disconnect.

3.Reverse any two of the unit power leads.

4.Turn on power to the unit and energize the compressor.

The suction and discharge pressure levels should now move to their normal start-up levels.

NOTE: When the compressor is rotating in the wrong direction, the unit makes more noise and does not provide cooling.

Step 9 —Cooling

Set the space thermostat to the OFF position. Set the system selector switch at COOL position and the fan switch at AUTO position. Adjust the thermostat to a setting below room temperature. The compressor starts when contactor closes.

Check cooling effects at a setting below room temperature. Check the unit charge. Refer to Refrigerant Charge section.

Reset the thermostat at a position above room temperature. The compressor will shut off.

To Shut Off Unit - Set the system selector switch at OFF position. Resetting the thermostat at a position above room temperature shuts off the unit temporarily until the space temperature exceeds the thermostat setting. Units are equipped