Carrier 50TFQ008-012 specifications Pre-Start-Up

PRE-START-UP

Failure to observe the following warnings could result in serious personal injury:

1.Follow recognized safety practices and wear protec- tive goggles when checking or servicing 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.

4.Relieve all pressure from the system before touching or disturbing anything inside the compressor terminal box if a refrigerant leak is suspected around the com- pressor terminals. Use accepted methods to recover 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.Relieve all pressure from the system using both the high and low-pressure ports. Use accepted methods to recover refrigerant.

c.Cut the component connection tubing with 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, CAU- TION, 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.

b.Inspect for oil at all refrigerant tubing connections and on the unit base. Detecting oil generally indi- cates a refrigerant leak. Leak-test all refrigerant tubing connections using an electronic leak detec- tor, halide torch, or liquid-soap solution.

c.Inspect all field-wiring and factory-wiring con- nections. Be sure that connections are completed and tight. Ensure that electrical wires do not contact refrigerant tubing.

d.Inspect the coil fins. If damaged during shipping and handling, carefully straighten the fins with a fin comb.

4.Verify the following conditions:

a.Make sure that the outdoor-fan blades are correctly positioned in the fan orifice. Refer to Outdoor-Fan Adjustment section on page 48 for more details.

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

c.Make sure that the 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

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

Return-Air Filters — Make sure that the correct filters are installed in the unit (see Table 1). Do not operate the unit without return-air filters.

Outdoor-Air Inlet Screen — The outdoor-air inlet screen must be in place before operating the unit.

Compressor Mounting — Compressors are internally spring mounted. Do not loosen or remove the compressor hold- down bolts.

Internal Wiring — Check all electrical connections in unit control boxes; tighten as required.

Refrigerant Service Ports — Each refrigerant system has 3 Schrader-type service gage ports: One on the suction line, one on the cooling mode liquid line, and one on the compressor discharge line. Be sure that the caps on the ports are tight. The port on the cooling mode liquid line and one port on the discharge line have protective devices installed on them.

HIGH FLOW REFRIGERANT VALVES — Two high flow valves may be located on the hot gas tube coming out of the compressor and the suction tube going into the compressor. Large black plastic caps identify these valves with O-rings inside screwing the cap and onto a brass body. No field access to these valves is available at this time. Ensure the plastic caps remain on the valves and are tight or the possibility of refriger- ant leakage could occur.

Compressor Rotation — It is important to be certain that the scroll compressor (size 012 only) is rotating in the proper direction. To determine whether or not the compressor is rotating in the proper direction:

1.Connect service gages to the suction and discharge pres- sure fittings.

2.Energize the compressor.

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

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

1.Note that the indoor fan 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. Re-energize 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 heating/cooling.

Cooling — To start the unit, turn on main power supply. 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 on closure of the contactor.

Check the unit charge. Refer to Refrigerant Charge section on page 48.

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 the unit off temporarily until the space temperature exceeds the thermostat setting.

The compressor restart is accomplished by manual reset at the thermostat by turning the selector switch to OFF position and then ON position.

44