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Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Catalog No. 04-53480165-01
Printed in U.S.A.
Form 48-50N-7T
Pg 1
12-2020
Replaces: 48-50N-6T
Controls, Start-Up, Operation,
Service and Troubleshooting
CONTENTS
Page
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . 2
GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Conventions Used in This Manual . . . . . . . . . . . . . . . 4
BASIC CONTROL USAGE . . . . . . . . . . . . . . . . . . . . . 4
ComfortLink Controls . . . . . . . . . . . . . . . . . . . . . . . . . 4
. . . . . . . . . . . . . . . . . . . . . . . . . . 4
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
. . . . . . . . . . . . . . . . . . . . . . . 5
CCN Tables and Display . . . . . . . . . . . . . . . . . . . . . . . 5
Unit Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Internal Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Accessory Installation . . . . . . . . . . . . . . . . . . . . . . . . 7
Crankcase Heaters . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Evaporator Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Gas Heat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
CONTROLS QUICK START . . . . . . . . . . . . . . . . . . . 27
VAV Units Using Return Air Sensor or Space
Temperature Sensor . . . . . . . . . . . . . . . . . . . . . . . 27
Multi-Stage CV and SAV Units with Mechanical
Thermostat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Multi-Stage CV and SAV Units with Space Sensor . 27
Economizer Configurations . . . . . . . . . . . . . . . . . . . 27
Indoor Air Quality Configurations . . . . . . . . . . . . . . 28
Exhaust Configurations . . . . . . . . . . . . . . . . . . . . . . 28
Set Clock on VFD . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Programming Operating Schedules . . . . . . . . . . . . 29
SERVICE TEST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Service Test Mode Logic . . . . . . . . . . . . . . . . . . . . . 29
Independent Outputs . . . . . . . . . . . . . . . . . . . . . . . . 29
Fans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Actuators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
. . . . . . . . . . . . . . . . . . . . . . . 33
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
SERVICE COMPONENT TESTS . . . . . . . . . . . . . . . . 34
Control Description (Overview) . . . . . . . . . . . . . . . . 34
Auto-Component Test Control Descriptions . . . . . 34
Digital Scroll Compressor (A1)
Auto-Component Test . . . . . . . . . . . . . . . . . . . . . 35
EXV Auto-Component Test . . . . . . . . . . . . . . . . . . . 35
Refrigerant Charge Auto-Test (without Liquid
Sensors) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Minimum Load Valve Auto-Component Test . . . . . 36
Supply Fan Auto-Component Test . . . . . . . . . . . . . .36
THIRD PARTY CONTROL . . . . . . . . . . . . . . . . . . . . .37
Thermostat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Alarm Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Remote Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
VFD Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Supply Air Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Demand Limit Control . . . . . . . . . . . . . . . . . . . . . . . .37
Economizer/Outdoor Air Damper Control . . . . . . . .37
CONTROLS OPERATION . . . . . . . . . . . . . . . . . . . . .39
Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
Unit Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . .42
Cooling Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Heating Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60
Static Pressure Control . . . . . . . . . . . . . . . . . . . . . . .69
Fan Status Monitoring . . . . . . . . . . . . . . . . . . . . . . . .71
Dirty Filter Switch . . . . . . . . . . . . . . . . . . . . . . . . . . .72
Economizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73
Building Pressure Control . . . . . . . . . . . . . . . . . . . .82
Smoke Control Modes . . . . . . . . . . . . . . . . . . . . . . . .84
Indoor Air Quality Control . . . . . . . . . . . . . . . . . . . . .84
Humidification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .88
Dehumidification and Reheat . . . . . . . . . . . . . . . . . .89
Humidi-MiZer Adaptive Dehumidification System . 90
Temperature Compensated Start . . . . . . . . . . . . . . .93
Carrier Comfort Network
(CCN) . . . . . . . . . . . . . . .93
Alert Limit Configuration . . . . . . . . . . . . . . . . . . . . . .94
Sensor Trim Configuration . . . . . . . . . . . . . . . . . . . .96
Discrete Switch Logic Configuration . . . . . . . . . . . .97
Display Configuration . . . . . . . . . . . . . . . . . . . . . . . .98
VFD Configurations . . . . . . . . . . . . . . . . . . . . . . . . . .98
Remote Control Switch Input . . . . . . . . . . . . . . . . .100
Hot Gas Bypass . . . . . . . . . . . . . . . . . . . . . . . . . . . .100
Space Temperature Offset . . . . . . . . . . . . . . . . . . .100
TIME CLOCK CONFIGURATION . . . . . . . . . . . . . . .101
Hour and Minute (HH.MM) . . . . . . . . . . . . . . . . . . . .101
Month of Year (MNTH) . . . . . . . . . . . . . . . . . . . . . . .101
Day of Month (DOM) . . . . . . . . . . . . . . . . . . . . . . . .101
Day of Week (DAY) . . . . . . . . . . . . . . . . . . . . . . . . . .101
Year (YEAR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101
Local Time Schedule (SCH.L) . . . . . . . . . . . . . . . . .101
Local Holiday Schedules (HOL.L) . . . . . . . . . . . . .101
Daylight Savings Time (DAY.S) . . . . . . . . . . . . . . .101
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . .103
Complete Unit Stoppage . . . . . . . . . . . . . . . . . . . . .103
Single Circuit Stoppage . . . . . . . . . . . . . . . . . . . . .103
WeatherExpert
®
48/50N2,N3,N4,N5,N6,N7,N8,N9
Packaged Rooftop Cooling Units with Gas Heat,
Optional Electric Heat, or Hydronic Heat and
Comfort
Link Controls Version 10.x
Summary of Contents for WeatherExpert 48N2
Page 135: ...135 Fig 18 48 50N Typical Power Schematic Nominal 075 Ton Unit Shown ...
Page 136: ...136 Fig 19 48 50N Typical Power Schematic Nominal Ton 90 150 Units Shown ...
Page 137: ...137 Fig 20 48 50N Main Base Board Input Output Connections ...
Page 138: ...138 Fig 21 48 50N RXB EXB CEM Input Output Connections a48 9307 ...
Page 139: ...139 Fig 22 48 50N EXV SCB Input Output Connections a48 9308 ...
Page 140: ...140 Fig 23 48N Typical Modulating Gas Heat Unit Control Wiring ...
Page 141: ...141 Fig 24 50N Typical Electric Heat Unit Control Wiring ...
Page 144: ...144 Fig 27 48N Typical Gas Heat Section Wiring Nominal Ton 120 to 150 Units ...
Page 145: ...145 Fig 28 48 50N Typical Power Component Control Wiring 460 v ...
Page 146: ...146 Fig 29 48 50N Component Control Wiring 575 v Nominal Ton 075 to 150 Units ...
Page 147: ...147 Fig 30 48 50N Component Arrangement Power Box ...
Page 148: ...148 Fig 31 48 50N Component Arrangement Control Box ...
Page 240: ...240 APPENDIX D VFD INFORMATION CONT Fig G VFD Bypass Wiring Diagram WHEN USED ...