Carrier 50NQ User Manual

50NQ
Single-Package Heat Pumps
HEATING A COOLING
Installation, Start-Up and Service Instructions
CONTENTS
Page
SAFETY CONSIDERATION. 1
INSTALLATION.1-7
Step 1—Moving and Setting Unit in Place.4
• ROOFTOP INSTALLATION
• GROUND-LEVEL INSTALLATION
• CLEARANCES
Step 2— C ondensate Disposal. 4
Step 3—Duct Connections.6
Step 4—Electrical Connections.6
• HIGH-VOLTAGE CONNECTIONS
• PROCEDURES FOR 208V
• CONTROL VOLTAGE CONNECTIONS
• HEAT ANTICIPATOR SETTING
• CIRCUIT BREAKER
PREPARING UNIT FOR START-UP.7
START-UP AND ADJUSTMENTS.9
CARE AND MAINTENANCE.10
NOTE TO INSTALLER: Leave these instructions and the
User’s Manual with the equipment user after installation.
INTRODUCTION
Model 50NQ Packaged Heat Pump Units are fully self-
contained, heating/cooling units designed for outdoor instal¬
lation. These units may be installed either on a rooftop or
ground-level slab. For rooftop downflow applications, an
accessory roof-mounting curb may be used.
SAFETY CONSIDERATIONS
Installing and servicing air conditioning equipment can be
hazardous due to system pressure and electrical compo¬
nents. Only trained and qualified service personnel should
install or service air conditioning equipment.
Untrained personnel can perform basic maintenance func¬
tions such as cleaning coils and filters and replacing filters.
All other operations should be performed by trained service
personnel. When working on air conditioning equipmei^,
observe precautions in the literature and on tags and labels
attached to unit.
Follow all safety codes. Wear safety glasses and work
gloves. Use quenching cloth for brazing operations. Have
fire extinguisher available.
Recognize safety information: This is the safety-alert sym¬
bol A, when you see this symbol on the unit and in instruc¬
tions or manuals, be alert to the potential for personal
injury.
Understand the signal word—DANGER, WARNING or
CAUTION. These words are used with the safety-alert sym¬
bol. DANGER identifies the most serious hazards which
will result in severe personal injury or death. WARNING,
on the other hand could result in personal injury or death.
CAUTION is used to identify unsafe practices, which would
Fig. 1—Model 50NQ
result in minor personal injury or product and property
damage.
1. This installation must conform with all applicable local
and national codes.
2. The power supply (volts, hertz, and phase) must corre¬
spond to that specified on unit rating plate. (See Fig. 4
for location.)
3. The electrical supply provided by the utility must be
sufficient to handle load imposed by this unit.
4. Refer to the dimensional drawings (Figs. 2 and 3) for
locations of electrical inlets, condensate drain, duct
connections, and required clearances before setting
unit in place.
5. Unit designed for outdoor installation on wood flooring
or on class A, B, or C roof covering materials.
GENERAL
Model 50NQ Packaged Heat Pump has been designed and
tested in accordance with ARI Standard 240, 270 and U.L.
Standard 559.
These units are factory-charged with R-22 refrigerant.
Installation is simple: connect air ducts, high- and low-
voltage wiring, condensate drain, and install a field-supplied
air filter.
All units can be connected into existing duct systems that
are properly sized and designed to handle an airflow of 375
to 450 Cfm per each 12,000 Btuh of rated cooling capacity.
Refer to pre-sale literature for detailed air delivery capacity.
NOTE: When installing any accessory item, see the manu¬
facturer’s Installation Instructions packaged with the
accessory. The Qualified Agency must use factory author¬
ized kits or accessories when modifying this unit.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
PC 101 Catalog No 565-116 Printed in U.S.A Form 50NQ-1SI Pg 1 7-89 Replaces: New
Book
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Tab
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Carrier 50NQ Specifications

General

HSPF	Up to 9.5
Sound Level	as low as 72 dB
Refrigerant	R-410A
Operating Temperature (Cooling)	55 to 125 °F
Warranty	10-year limited parts warranty

Summary

SAFETY CONSIDERATION

INSTALLATION PROCEDURES

Step 1-Moving and Setting Unit in Place

Guidance on safely moving and positioning the unit for installation.

PREPARING UNIT FOR START-UP

Procedures for preparing the unit before initial startup.

START-UP AND ADJUSTMENTS

Steps and adjustments required for starting the unit.

CARE AND MAINTENANCE

Guidelines for maintaining the unit for optimal performance and longevity.

Moving and Setting Unit in Place

Condensate Disposal

Duct Connections

Electrical System Details

High-Voltage Connections

Instructions for connecting high-voltage power to the unit.

208-V Operation Procedures

Control Voltage Connections

Preparing Unit for Start-Up

Refrigerant Leaks and Checks

Refrigerant Leak Procedures

Procedures for identifying, repairing, and testing for refrigerant leaks.

Checking Refrigerant Charge

Start-Up and Adjustments

Indoor Airflow and Adjustments

Care and Maintenance

Coil and Drain Pan Cleaning

Metering Device Servicing

Checking Start Thermistor

Troubleshooting: Cooling Cycle

Troubleshooting: Heating Cycle