Carrier 50PG20 Installation Instructions Manual

50PG20---28
Single Package Rooftop Units
Electric Cooling with Electric Heat Option and
COMFORTLINKt with PURONR (R---410A) Refrigerant
IMPORTANT: This installation instruction contains basic unit
installation information including installation of field control
devices. For information on unit start-up, service, and operation,
refer to the unit Controls, Start-Up, Operation, Service, and
Troubleshooting Instructions also enclosed in the unit literature
packet.

TABLE OF CONTENTS

SAFETY CONSIDERATIONS
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Step 1 - - Provide Unit Support
Step 2 - - Remove Shipping Rails
Step 3 - - Rig and Place Unit
Step 4 - - Field Fabricate Ductwork
Step 5 - - Make Unit Connections
Step 6 - - Trap Condensate Drain
Step 7 - - Make Electrical Connections
Step 8 - - Install Outdoor- -Air Hood
Step 9 - - Position Optional Power Exhaust or
Barometric Relief Damper Hood
Step 10 - - Non- -Fused Disconnect
Step 11 - - Install All Accessories
Step 12 - - Configure Controls

SAFETY CONSIDERATIONS

Installation and servicing of air-conditioning equipment can be
hazardous due to system pressure and electrical components. Only
trained and qualified service personnel should install, repair, or
service air-conditioning equipment.
Untrained personnel can perform the basic maintenance functions
of replacing filters. All other operations should be performed by
trained service personnel. When working on air-conditioning
equipment, observe precautions in the literature, tags and labels
attached to the unit, and other safety precautions that may apply.
Follow all safety codes. Wear safety glasses and work gloves. Use
quenching cloth for unbrazing operations. Have fire extinguishers
available for all brazing operations.
Recognize safety information. This is the safety- -alert symbol
When you see this symbol on the furnace and in instructions or
manuals, be alert to the potential for personal injury.
Installation Instructions
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Understand the signal words DANGER, WARNING, and
CAUTION. These words are used with the safety- -alert symbol.
DANGER identifies the most serious hazards which will result in
severe personal injury or death. WARNING signifies a hazard
which could result in personal injury or death. CAUTION is used
to identify unsafe practices which may result in minor personal
injury or product and property damage. NOTE is used to highlight
suggestions which will result in enhanced installation, reliability, or
operation.
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1
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UNIT OPERATION AND SAFETY HAZARD
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Failure to follow this warning could cause personal
injury, death and/or equipment damage.
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Puron (R- -410a) refrigerant systems operate at higher
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pressures than standard R- -22 systems. Do not use R- -22
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service equipment or components on Puron refrigerant
equipment.
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25
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ELECTRICAL SHOCK HAZARD
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Failure to follow this warning could cause personal
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injury or death.
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Before performing service or maintenance operations
on unit, turn off main power switch to unit and install
lockout tag. Ensure electrical service to rooftop unit
agrees with voltage and amperage listed on the unit
rating plate.
IMPORTANT: Units have high ambient operating limits. If limits
are exceeded, the units will automatically lock the compressor out
of operation. Manual reset will be required to restart the
compressor.
Step 1 -Provide Unit Support
Roof Curb
Assemble or install accessory roof curb in accordance with
instructions shipped with this accessory. (See Fig. 1.) Install
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insulation, cant strips, roofing, and counter flashing as shown.
Ductwork can be installed to roof curb before unit is set in place.
Ductwork must be attached to curb and not to unit. Curb must be
level. This is necessary to permit unit drain to function properly.
Unit leveling tolerance is ±
Refer to Accessory Roof Curb Installation Instructions for
additional information as required. When accessory roof curb is
used, unit may be installed on class A, B, or C roof covering
material. Carrier roof curb accessories are for flat roofs or slab
mounting.
WARNING
WARNING

INSTALLATION

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/ in. per linear ft in any direction.
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