Carrier 48/50HJ004-014 specifications Pre-Start-Up, Service

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 and gloves when checking or servicing refrigerant system.

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

3.Do not remove compressor terminal cover until all electrical sources are disconnected and tagged accordingly.

4.Relieve all pressure from system before touching or disturbing any connections inside compressor ter- minal box. If refrigerant leak is suspected around compressor terminals, use accepted methods to recov- er refrigerant.

5.Never attempt to repair or solder any components while refrigerant system is under pressure.

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

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

b.Recover refrigerant to relieve all pressure from system, using both high- and low-pressure ports.

c.Cut component connection 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.

Refer to 48/50HJ Installation Instructions for Pre-Start-Up information for the rooftop unit section. Proceed as follows to inspect and prepare the unit for initial start-up:

1.Remove filter access panel, blower access panel, and con- trol panel access cover on the energy recovery section.

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 or handling damages such as broken lines, loose parts, or disconnected wires.

b.Inspect for oil at all refrigerant tubing connections and on unit base. Detecting oil usually indicates a refrigerant leak. Leak-test all refrigerant tubing connections using an electronic leak detector, halide torch, or liquid-soap solution.

c.Inspect all field and factory wiring connections Be sure that connections are completed and tight.

d.Inspect upper (supply) and lower (exhaust) coils for damage and refrigerant leaks. If fin damage is noted, carefully straighten fins using a fin comb.

4.Tighten compressor holddown bolts to 5.5 to 6.5 ft-lbs of torque.

5.Verify the following:

a.If installed, ensure optional supply and exhaust blower wheel set screws are tight and wheels are centered within the blower housing.

b.Make sure supply and exhaust air filters are in place.

c.Make sure the condensate drain is of correct dimensions and primed with water to ensure proper drainage.

d.Reinstall all access panels.

e.Ensure all tools and miscellaneous parts have been removed.

START-UP

Refer to the 48/50HJ Installation Instructions for informa- tion on Start-Up for the rooftop unit section.

Unit Preparation — Make sure the unit has been in- stalled in accordance with installation instructions and applica- ble codes.

Supply and Exhaust Filters — Make sure filters are correctly installed on unit. Do not operate without filters in place.

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

Compressor Mounting — Compressors are internally spring-mounted. Ensure wooden shipping block has been removed from under the compressor and holddown bolts are in place.

Internal Wiring — Check all low and high voltage con- nections for proper locations. Ensure connections are tight.

Cooling — Set Light Commercial Thermidistat mode selec- tion to Cooling and fan mode to Auto. Ensure thermostat has been adjusted to a setting below room temperature. Refer to Table 2 for correct unit operation.

Heating — Set Light Commercial Thermidistat mode se- lection to Heating and fan mode to Auto. Ensure thermostat has been adjusted to a setting below room temperature. Refer to Table 2 for correct unit operation.

Operating Sequence — Refer to Step 5 — Conduct Light Commercial Thermidistat Start-Up and Checkout on page 33, and Table 2 for energy recovery section operating sequence. See Fig. 17.

SERVICE

Refer to base unit installation instructions or 62AQ Installa- tion Instruction for all service information.

Fuse Box (48HJ012,014 — 208/230-3-60 Units Only) — Certain 48HJ units contain a fuses for the power supply. The fuse box is located in the compressor section in a single point box. See Fig. 18. Replacement fuses are cartridge type, non-renewable, time delay FRN type of the appropriate size and voltage. Refer to existing fuse size and voltage for replacement.

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