Carrier 48LDT004 - User Manual

Carrier Corporation • Syracuse, N Y 13221
Combination Heating/Cooling Units
INDEX
Page
SAFETY CONSIDERATIONS. 1
INSTALLATION .1-16
Step 1 — Provide Unit Support . 1
• ROOF CURB
• SLAB MOUNT
Step 2 — Field Fabricate Ductwork. 1
Step 3 — Rig and Place Unit. 1
• POSITIONING
Step 4 — Install Flue Hood . 3
Step 5 — Trap Condensate Drain . 3
Step 6 — Install Gas Piping. 3
Step 7 — Make Electrical Connections. 3
• FIELD POWER SUPPLY
• FIELD CONTROL WIRING
• HEAT ANTICIPATOR SETTINGS
Step 8 — Make Outdoor Air Inlet Adjust¬
ments and Install Outdoor Air Hood. 10
• OPTIONAL OUTDOOR AIR DAMPER
• OPTIONAL ECONOMIZER
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INSTALLATION
NOTE: 004,005,006 size units in California require
the installation of an accessory NOx baffle. Refer to
Accessory NOx Baffle Installation Instructions for
details.
Step 1 — Provide Unit Support
ROOF CURB (Downshot Units Only) — Assemble
and install accessory roof curb in accordance with
instructions shipped with curb. Curb details and
information required to field fabricate a roof curb
are shown in Fig. 1. Install insulation, cant strips,
roofing and flashing as shown. Ductwork must be
attached to curb.
Step 9 — Adjust Evaporator Fan Speed. 16
START-UP.16,17
SERVICE.18-22
SAFETY CONSIDERATIONS
Installation and servicing of air conditioning
equipment can be hazardous due to system pressure
and electrical components. Only trained and quali¬
fied service personnel should install, repair or
service air conditioning equipment.
Untrained personnel can perform basic mainte¬
nance functions of cleaning coils and filters and
replacing filters. All other operations should be per¬
formed 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.
Curb should be level. Unit leveling tolerance is
1/16 in. per linear foot in any direction. This is
necessary for unit drain to function properly. Refer
to Accessory Roof Curb Installation Instructions
for additional information as required.
SLAB MOUNT(Horizontal Units Only) — Provide
a level concrete slab that extends a minimum of 6 in.
beyond unit cabinet. The slab should be 8 in. thick
with 4 in. above grade. Install a gravel apron in front
of condenser air inlet to prevent grass and foliage
from obstructing airflow. Trap condensate drai.n.
Allow for trap when pouring slab.
Step 2 — Field Fabricate Ductwork — On
downshot units secure all ducts to roof curb and
building structure.
lHiiH Insulate and weatherproof all external duct¬
work, joints and roof openings with flashing and
mastic in accordance with applicable codes.
Ducts passing through an unconditioned space
must be insulated and covered with a vapor barrier.
A minimum clearance is not required around
ductwork. Cabinet return air static shall not exceed
-.35 in. wg with economizer or -.45 in. wg without
economizer.
Step 3 — Rig and Place Unit — Inspect unit for
transportation damage. File any claim with trans¬
portation agency. Keep upright and do not drop.
Carrier Corporation 1984
Form 48H.L-7SI

Carrier 48LDT004 Specifications

General

Model	48LDT004
Product Type	Air Handler
Airflow	1600 CFM
Voltage	208/230V
Phase	1
Refrigerant	R-410A
Motor Type	PSC
Cabinet Construction	Galvanized steel
Tonnage	4 tons

Summary

Safety Considerations

General Safety Precautions

Installation and servicing of air conditioning equipment can be hazardous due to system pressure and electrical components. Only trained personnel should perform these tasks.

Pressure Testing Warning

WARNING: When pressure testing field-supplied gas piping at pressures above 0.5 psig, unit components must be disconnected from piping to prevent damage and hazards.

Installation - Unit Support and Rigging

Step 1: Provide Unit Support

Assemble and install accessory roof curb in accordance with instructions shipped with curb. Ensure proper leveling and insulation for water integrity.

Step 2: Field Fabricate Ductwork

Step 3: Rig and Place Unit

Installation - Gas and Electrical

Step 6: Install Gas Piping

Step 7: Make Electrical Connections

Check all electrical connections in unit control boxes. Ensure proper wiring, grounding, and compliance with National Electrical Code and local requirements.

Start-Up Procedures

Unit Preparation

Ensure unit is installed per instructions and applicable codes. Verify correct filters are installed and outdoor air screens are in place.

Cooling Start-Up

Heating Start-Up

Service - Cleaning Procedures

Evaporator Coil Cleaning

Turn unit power off, remove access panel, disconnect wiring, and slide fan motor housing out to clean the coil.

Condenser Coil Cleaning

Inspect coil monthly. Clean annually or as needed by location. Shine flashlight to check for dirt between coil sections.

Service - Adjustments and Charging

Condenser Air Fan Adjustment

Refrigerant Charge Procedure

Use standard evacuating techniques. Weigh in the specified amount of refrigerant per unit nameplate or charging chart.

Service - Burner System Operations

Main and Pilot Burner Service

Automatic Pilot Adjustment

Pilot Light Troubleshooting