TRANSFORMER CONTAINS A MANUAL RESET OVERCURRENT PROTECTOR

IT WILL NOT AUTOMATICALLY RESET

DISCONNECT POWER PRIOR TO SERVICING

THIS COMPARTMENT MUST BE CLOSED EXCEPT WHEN SERVICING

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

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 outdoor-fan blade is correctly positioned in

fan orifice.

b. Make sure that condensate drain pan and trap are filled

Fig. 19ÐTransformer Label

C99058

with water to ensure proper drainage.

c. Make sure that all tools and miscellaneous loose parts have

SPECIAL PROCEDURES FOR 208-V OPERATION

1.Disconnect the yellow primary lead (w110) from the trans- former. See unit wiring label (See Fig. 12 through 14).

2.Connect the yellow primary lead (w110) to the transformer terminal labeled 200v.

Indoor blower-motor speeds may need to be changed for 208-v operation. Refer to indoor airflow and airflow adjustments section.

PRE-START-UP

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

1.Follow recognized safety practices and wear protective goggles 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 electri- cal sources are disconnected.

4.Relieve and recover all refrigerant from system before touching or disturbing anything inside terminal box if refrigerant leak is suspected around compressor terminals.

5.Never attempt to repair soldered connection while refrig- erant 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 proceed as follows:

a.Shut off electrical power to unit.

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 neces- sary. Oil can ignite when exposed to torch flame.

Use the Start-Up Checklist supplied at the end of this book and proceed as follows to inspect and prepare the unit for initial start-up:

1.Remove access panel.

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 refrig- erant leak is detected, see following Check for Refrigerant Leaks section.

 

been removed.

5.

Compressors are internally spring mounted. Do not loosen or

 

remove compressor hold-down bolts.

6.

Each unit system has 2 Schrader-type ports, one low-side

 

Schrader fitting located on the suction line, and one high-side

 

Schrader fitting located on the compressor discharge line. Be

 

sure that caps on the ports are tight.

MOTOR

FAN GRILLE

1/8" MAX BETWEEN

MOTOR SHAFT

MOTOR AND FAN HUB

C99009

Fig. 20ÐFan Blade Clearance

START-UP

Using the Start-Up Checklist supplied at the end of this book, proceed as follows:

Step 1ÐCheck for Refrigerant Leaks

Locate and repair refrigerant leaks and charge the unit as follows:

1.Use both high- and low-pressure ports to relieve system pressure and reclaim remaining refrigerant

2.Repair leak following accepted practices.

NOTE: Install a bi-flow filter drier whenever the system has been opened for repair.

3.Check system for leaks using an approved method.

4.Evacuate refrigerant system and reclaim refrigerant if no additional leaks are found.

5.Charge unit with R-22 refrigerant, using a volumetric- charging cylinder or accurate scale. Refer to unit rating plate for required charge. Be sure to add extra refrigerant to compensate for internal volume of filter drier.

Step 2ÐStart-Up Adjustments

Complete the required procedures given in the Pre-Start-Up section on this page before starting the unit. Do not jumper any safety devices when operating the unit. Do not operate the unit in Cooling mode when the outdoor temperature is below 40°F (unless accessory low-ambient kit is installed). Do not rapid-cycle the compressor. Allow 5 min. between ``on'' cycles to prevent compressor damage.

CHECKING COOLING AND HEATING CONTROL OPERA- TION Ð Start and check the unit for proper 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 within 60 sec. when FAN switch is placed in AUTO position.

15

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Carrier 50JS Special Procedures for 208-V Operation, Pre-Start-Up, ÐCheck for Refrigerant Leaks, ÐStart-Up Adjustments

50JS specifications

The Carrier 50JS is a high-performance rooftop unit designed for commercial applications, combining advanced technology with energy efficiency to deliver optimal heating and cooling performance. Its compact design allows for easy installation, making it an ideal choice for various settings such as retail spaces, schools, and office buildings.

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