Carrier 48NLT - Manual

HEATING & COOLING
48NLT, NMT, NET, NHT AND NVT 018-060
Packaged Heating/Cooling Units
Installation, Start-Up and Service Instructions
CONTENTS
SAFETY CONSIDERATIONS
General ...................................
Job Data ..................................
Page
. 1
. 1
. 1
1-10
. 1
RECEIVING AND INSTALLATION....................
Step 1 — Check Equipment ............................
• IDENTIFY MACHINE
• INSPECT SHIPMENT
Step 2 — Provide Unit Support............................... 4
• ROOF CURB
• SLAB MOUNT
Step 3 — Provide Ciearances .................................4
Step 4 — Rig and Place Unit....................................4
Step 5 — Connect Condensate Drain..................... 5
Step 6 -
instali Venting ...................................... 6
Step 7 - Instail Gas Piping................................. 6
Step 8 — Instail Duct Connections.....................7
Step 9 -
Instail Electrical Connections.............8
• HIGH VOLTAGE CONNECTIONS
• SPECIAL PROCEDURES FOR 208-V
OPERATION
• CONTROL VOLTAGE CONNECTIONS
• HEAT ANTICIPATOR SETTING
• TRANSFORMER CIRCUIT PROTECTION
PRE-START-UP
START-UP..........
MAINTENANCE
10,11
11-20
20-26
NOTE TO INSTALLER — Before the installation, READ
THESE INSTRUCTIONS CAREFULLY AND COM­
PLETELY. Also, make sure the User’s Manual and Re­
placement Guide are left with the unit after installation.
SAFETY CONSIDERATIONS
Installation and servicing of air conditioning equipment
can be hazardous due to system pressure and electrical com­
ponents. Only trained and qualified personnel should in­
stall, repair or service air conditioning equipment.
Untrained personnel can perform basic maintenance func­
tions of cleaning coils and 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 extinguisher available for all brazing operations.
A WARNING
Improper installation, adjustment, alteration, service, main­
tenance or use can cause carbon monoxide poisoning, fire
or an explosion which can result in personal injury or
unit damage. Consult a qualified installer, service agency
or gas supplier for information or assistance. The quali­
fied installer or agency must use only factory-authorized
kits or accessories when modifying this product.________
Fig. 1 - Model 48NLT, NMT, NET, NHT and NVT
A WARNING
Before performing service or maintenance operations
on unit, turn off unit main power switch. Electrical shock
could cause personal injury.
General - The 48NLT, NMT, NET, NHT and NVT
units are fully self-contained, combination gas heating/
cooling units designed for outdoor installation. See Fig. 1.
The units are shipped in a vertical configuration and may
be installed either on a rooftop or converted to horizontal
configuration when placed on a ground-level cement slab.
Job Data — Necessary information consists of:
machine location drawings, piping drawings, field wiring
diagrams and rigging guide.
RECEIVING AND INSTALLATION
Step 1 — Check Equipment
IDENTIFY MACHINE — The machine model number and
serial number are stamped on machine identification plate.
Check this information against shipping papers and job data.
INSPECT SHIPMENT — Inspect for shipping damage while
machine is still on shipping pallet. If machine appears to be
damaged or is torn loose from its anchorage, have it exam­
ined by transportation inspectors before removal. Forward
claim papers directly to transportation company. Manufac­
turer is not responsible for any damage incurred in transit.
Check all items against shipping list. Immediately notify
the nearest Carrier Air Conditioning office if any item is
missing.
To prevent loss or damage, leave all parts in original pack­
ages until installation.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obiigations.
Book|1 |4 PC 111 Catalog No 564-920 Printed in U.S,A. Form 48NT-20SI Pg 1 11-91 Replaces: 48NT-19SI
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