Carrier 50SD - User Manual

50SD
Single Packaged Electric Cooling Units
Installation, Start-Up, and Operating Instructions
Sizes 024-060
NOTE: Read the entire instruction manual before starting the
installation.
This symbol → indicates a change since the last issue.
TABLE OF CONTENTS
SAFETY CONSIDERATIONS .....................................................1
RULES FOR SAFE INSTALLATION AND OPERATION.......2
INTRODUCTION ..........................................................................2
RECEIVING AND INSTALLATION ..........................................2
Check Equipment......................................................................2
IDENTIFY UNIT ................................................................2
INSPECT SHIPMENT ........................................................2
Provide Unit Support ................................................................2
ROOF CURB.......................................................................2
SLAB MOUNT ...................................................................2
GROUND MOUNT ............................................................2
Provide Clearances....................................................................2
Field Fabricate Ductwork .........................................................2
Rig and Place Unit....................................................................2
INSPECTION ......................................................................4
INSTALLATION ................................................................4
Connect Condensate Drain .......................................................7
Install Duct Connections ..........................................................7
CONFIGURING UNITS FOR DOWNFLOW (VERTI-
CAL) DISCHARGE ............................................................7
Install Electrical Connection ....................................................9
HIGH-VOLTAGE CONNECTIONS..................................9
SPECIAL PROCEDURES FOR 208-V OPERATION .....9
CONTROL VOLTAGE CONNECTIONS.........................9
STANDARD CONNECTION ..........................................10
TRANSFORMER PROTECTION....................................12
PRE-START-UP ..........................................................................12
START-UP ...................................................................................12
CHECK FOR REFRIGERANT LEAKS..........................12
START UP COOLING SECTION AND MAKE ADJUST-
MENTS..............................................................................12
CHECKING COOLING CONTROL OPERATION .......12
CHECKING AND ADJUSTING REFRIGERANT
CHARGE ...........................................................................12
INDOOR AIRFLOW AND AIRFLOW ADJUST-
MENTS..............................................................................14
For 208/230V.....................................................................14
COOLING SEQUENCE OF OPERATION.....................14
MAINTENANCE.........................................................................14
AIR FILTER......................................................................15
EVAPORATOR BLOWER AND MOTOR.....................15
CONDENSER COIL, EVAPORATOR COIL, AND CON-
DENSATE DRAIN PAN ..................................................16
CONDENSER FAN ..........................................................16
ELECTRICAL CONTROLS AND WIRING ..................16
REFRIGERANT CIRCUIT...............................................16
EVAPORATOR AIRFLOW .............................................17
METERING DEVICE — ACCURATER ........................17
TROUBLESHOOTING ...............................................................17
START-UP CHECKLIST............................................................17
NOTE TO INSTALLER — Before the installation, READ THESE
INSTRUCTIONS CAREFULLY AND COMPLETELY. Also,
make sure the User’s Manual and Replacement 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 components. Only
trained and qualified personnel should install, repair, or service
air-conditioning equipment.
Untrained personnel can perform basic maintenance functions 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. Consult a qualified installer or
service agency for information or assistance. The qualified in-
staller or agency must use only factory-authorized kits or acces-
sories when modifying this product.
Fig. 1—Model 50SD
C99001
Visit www.carrier.com
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 6
Tab 6 8
PC 101 Printed in U.S.A. Catalog No. 50SD-1SI Pg 1 8-05 Replaces: New

Summary

Safety and General Information

Safety Rules for Installation and Operation

Guidelines for safe installation and operational procedures to prevent injury.

Unit Introduction and Overview

Overview of the 50SD unit, its purpose, and basic features.

Unit Installation and Setup

Receiving, Identification, and Inspection

Procedures for checking equipment, unit identification, and shipment inspection.

Unit Support and Placement Options

Instructions for supporting and placing the unit on roof curbs, slabs, or ground.

Site Preparation and Ductwork

Requirements for clearances, field ductwork, and rigging the unit.

Installation Details and Connections

Specific installation steps including inspection, duct connections, and condensate drain.

Electrical and Control Wiring Installation

Detailed instructions for high-voltage and control voltage electrical connections.

Standard Connection and Transformer Protection

Standard electrical connection methods and transformer protection details.

Pre-Start-Up and Start-Up Procedures

Pre-Start-Up Checks and Preparations

Steps to prepare the unit for initial startup, including safety checks and inspections.

Refrigerant Leak Detection and Charge Adjustment

Procedures for leak detection, repair, and refrigerant charge adjustment using superheat.

Airflow and Cooling Control Verification

Checking and adjusting indoor airflow and cooling control operation.

Cooling Sequence of Operation

Explanation of how the cooling cycle operates.

Maintenance and Troubleshooting

Routine Maintenance Tasks

Scheduled maintenance for air filters, coils, blower motors, and electrical connections.

System Component Inspections

Annual inspection of electrical controls, refrigerant circuit, and airflow systems.

Cooling System Troubleshooting Guide

Using the troubleshooting guide for cooling system problems and their remedies.

Start-Up Checklist

A checklist to ensure all proper start-up procedures are followed before unit operation.

Carrier 50SD Specifications

General

Brand	Carrier
Model	50SD
Category	Air Conditioner
Language	English