Table of Contents
RT-SVX34F-EN
5
Variable Air Volume Applications (Traditional
VAV)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Supply Air Temperature Control - Occupied
Cooling and Heating . . . . . . . . . . . . . . . . 47
Supply Air Temperature Control with an
Economizer . . . . . . . . . . . . . . . . . . . . . . . . 47
VHR Relay Output . . . . . . . . . . . . . . . . . . . 47
Zone Temperature Control without a
Night Setback Panel or ICS - Unoccupied
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Zone Temperature Control without a
Night Setback Panel or ICS - Unoccupied
Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Morning Warm-up (MWU) Control . . . . . 47
Daytime Warm-up (DWU) Control . . . . . 47
Supply Duct Static Pressure Control . . . 48
Supply Air Temperature Reset . . . . . . . . 48
VAV Supply Air Tempering (Only Available
with Modulating Gas Heat) . . . . . . . . . . . 48
Constant Volume or Variable Air Volume Ap-
plications (Single Zone or Traditional)
. . . 49
Off Mode . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Zone Temperature - Unoccupied Cooling (CV
or SZ VAV Only) . . . . . . . . . . . . . . . . . . . . 49
Zone Temperature - Unoccupied Heating 49
Mechanical Cooling with an Economizer 49
Gas Heat Control . . . . . . . . . . . . . . . . . . . 49
Electric Heat Control . . . . . . . . . . . . . . . . 50
Clogged Filter Option . . . . . . . . . . . . . . . . 50
Ventilation Override . . . . . . . . . . . . . . . . . 50
Emergency Stop . . . . . . . . . . . . . . . . . . . . 50
Phase Monitor . . . . . . . . . . . . . . . . . . . . . 50
Low Pressure Control . . . . . . . . . . . . . . . . 51
Dehumidification Low Pressure Control . 51
High Pressure Cutout and Temperature Dis-
charge Limit . . . . . . . . . . . . . . . . . . . . . . . 51
Power Exhaust Control (Standard) . . . . . 51
Space Pressure Control - Statitrac . . . . . 51
Power Exhaust Control (Tracking) . . . . . 52
Lead/Lag Control . . . . . . . . . . . . . . . . . . . 52
Coil Frost Protection . . . . . . . . . . . . . . . . . 52
Dehumidification Frost Protection . . . . . 52
VFD Programming Parameters . . . . . . . . 52
Condenser Fan Sequencing Control . . . . .52
Preparing the Unit for Operation
. . . . . . . .53
Electrical Phasing . . . . . . . . . . . . . . . . . . . .54
Voltage Supply and Voltage Imbalance . .54
Starting the Unit
. . . . . . . . . . . . . . . . . . . . . . .55
Test Modes . . . . . . . . . . . . . . . . . . . . . . . . .55
Verifying Proper Fan Rotation . . . . . . . . . .59
Verifying Proper Air Flow (CFM) -
CV or VFD's . . . . . . . . . . . . . . . . . . . . . . . . .59
Exhaust Fan Operation . . . . . . . . . . . . . . .72
Economizer Damper Adjustment
. . . . . . . .74
Economizer (O/A) Dampers . . . . . . . . . . . .74
Manual Fresh Air Damper . . . . . . . . . . . . .75
Starting the Compressor
. . . . . . . . . . . . . . .76
Starting 27.5 to 35 Ton Units . . . . . . . . . .76
Starting 40 to 50 Ton Units . . . . . . . . . . . .76
Compressor Oil . . . . . . . . . . . . . . . . . . . . .77
Scroll Compressor Operational Noises . .85
Compressor Crankcase Heaters . . . . . . . .85
Charging by Subcooling . . . . . . . . . . . . . .85
Measuring Subcooling . . . . . . . . . . . . . . .85
Gas Heat Units
. . . . . . . . . . . . . . . . . . . . . . . .85
Electric Heat Units
. . . . . . . . . . . . . . . . . . . . .86
Final Unit Checkout
. . . . . . . . . . . . . . . . . . . .86
For Constant Volume Units . . . . . . . . . . . .86
For Variable Air Volume Units . . . . . . . . .86
For Single Zone Variable Air Volume
Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87
Pre-Installation
. . . . . . . . . . . . . . . . . . . . . . . . . .88
General Unit Requirements
. . . . . . . . . . . . .88
Downflow/Upflow Models: . . . . . . . . . . . .88
All Units: . . . . . . . . . . . . . . . . . . . . . . . . . . .88
Electrical Requirements
. . . . . . . . . . . . . . . .88
Field Installed Control Wiring . . . . . . . . . .88
Gas Heat Requirements
. . . . . . . . . . . . . . . .88
Sequence of Operation
. . . . . . . . . . . . . . . . . . .89
Mechanical Cooling Sequence
Of Operation
. . . . . . . . . . . . . . . . . . . . . . . . . .89
Units Without an Economizer . . . . . . . . . .89
Economizer Operation Based on Dry Bulb 89