Table of Contents
6 OAU-SVX01H-EN
Model Number Descriptions . . . . . . . . . . . . . . 8
Horizon Outdoor Air Unit . . . . . . . . . . . . . . . 8
General Information . . . . . . . . . . . . . . . . . . . . 11
Overview of Manual . . . . . . . . . . . . . . . . . 11
Model Number Description . . . . . . . . . . . 11
Unit Nameplate . . . . . . . . . . . . . . . . . . . . 11
Compressor Nameplate . . . . . . . . . . . . . . 11
Unit Description . . . . . . . . . . . . . . . . . . . . 11
Indoor Fan Failure Input . . . . . . . . . . . . . 11
Low Pressure Control ReliaTel Control . 11
Refrigerant Circuits . . . . . . . . . . . . . . . . . 11
High Pressure Control ReliaTel Control . 11
Space Temperature / RH Sensor (Optional)
12
High Temperature Sensor . . . . . . . . . . . . 12
Outdoor Air Temperature and Relative Hu-
midity Sensor . . . . . . . . . . . . . . . . . . . . . . 12
Hot Gas Reheat . . . . . . . . . . . . . . . . . . . . . 12
100 Percent Outdoor Air Hood with Damper
and Filters . . . . . . . . . . . . . . . . . . . . . . . . . 12
Modulating Indirect Fired Gas Burner . . 12
Through the Base Electrical with Disconnect
Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Through the Base Gas Piping . . . . . . . . . 12
Hinged Access Doors . . . . . . . . . . . . . . . . 12
Modulating Electric Heat . . . . . . . . . . . . . 12
Unit Inspection . . . . . . . . . . . . . . . . . . . . . . . 13
First Aid Measures . . . . . . . . . . . . . . . . . . 13
Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Unit Clearances . . . . . . . . . . . . . . . . . . . . 13
Unit Clearances, Curb Dimensions, and Dimen-
sional Data
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
OAK Units . . . . . . . . . . . . . . . . . . . . . . . . . 14
OAN Units . . . . . . . . . . . . . . . . . . . . . . . . . 18
Unit Weight and Rigging . . . . . . . . . . . . . . . . 22
Unit Weight . . . . . . . . . . . . . . . . . . . . . . . . 22
Rigging . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Ductwork . . . . . . . . . . . . . . . . . . . . . . . . . . 25
General Unit Requirements . . . . . . . . . . . 25
Main Electrical Power Requirements . . . .26
Condensate Drain Configuration . . . . . . .26
Chilled Water Connection Size and Location
27
Filter Installation . . . . . . . . . . . . . . . . . . . . .27
Field Installed Power Wiring . . . . . . . . . . .27
Main Unit Power . . . . . . . . . . . . . . . . . . . . . .28
Standard Wiring . . . . . . . . . . . . . . . . . . . . .29
Voltage Imbalance . . . . . . . . . . . . . . . . . . .29
Electrical Phasing (Three-Phase Motors) .30
Compressor Crankcase Heaters . . . . . . . .30
Main Unit Display and ReliaTel Controls .31
Field-Installed Control Wiring . . . . . . . . . .31
Control Power Transformer . . . . . . . . . . .31
Controls Using 24 Vac . . . . . . . . . . . . . . . .32
Controls Using DC Analog Input/Output
(Standard Low Voltage Multiconductor Wire)
32
DC Conductors . . . . . . . . . . . . . . . . . . . . . . . .33
Factory-Provided Sensors . . . . . . . . . . . . . .33
Pre-Start Check List . . . . . . . . . . . . . . . . . . . . . .34
System Configuration and Pre-Start . . . . . . .35
Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
Indirect Fired Gas Heating Startup . . . . . . .38
Startup Procedure . . . . . . . . . . . . . . . . . . .39
Safety Controls . . . . . . . . . . . . . . . . . . . . . .42
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Monthly Maintenance . . . . . . . . . . . . . . . . . .43
Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Supply/Return Air Smoke Detector Mainte-
nance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Cooling Season . . . . . . . . . . . . . . . . . . . . .43
Heating Season . . . . . . . . . . . . . . . . . . . . .43
Condenser Coil Cleaning . . . . . . . . . . . . . .44
Final Process . . . . . . . . . . . . . . . . . . . . . . . . . .45
Performance Data . . . . . . . . . . . . . . . . . . . . . . .47
Superheat and Refrigeration Circuit Data .57
Non-Heat Pump Units . . . . . . . . . . . . . . . .57
ASHP Units . . . . . . . . . . . . . . . . . . . . . . . . .61
Alarms and Troubleshooting . . . . . . . . . . . . .65