RN SERIES Packaged Rooftop Units, Heat Pumps,

& Outdoor Air Handling Units

Installation, Operation & Maintenance

o Do not store gasoline or other flammable

vapors and liquids in the vicinity of this or any other appliance

o WHAT TO DO IF YOU SMELL GAS Do not try to light any appliance. Do not tough any electrical switch; do not

use any phone in your building. Leave the building immediately. Immediately call your gas supplier from a

phone remote from the building. Follow the gas suppliers instructions.

If you cannot reach your gas supplier, call the fire department.

o Installation and service must be performed by a qualified installer, service agency or the gas supplier.

WARNING

FIRE OR EXPLOSION HAZARD

Failure to follow safety warnings exactly could result in serious injury, death or property damage. Be sure to read and understand the installation, operation and service instructions in this manual. Improper installation, adjustment, alteration, service or maintenance can cause serious injury, death or property damage. A copy of this IOM should be kept with the unit.

WARNING

3

Table of Contents

Safety .............................................................................................................................................. 7 RN Base Model Description ......................................................................................................... 12 General Information ...................................................................................................................... 22

Codes and Ordinances............................................................................................................... 22 Receiving Unit .......................................................................................................................... 23 Packaged Direct Expansion (DX) Units ................................................................................... 24 Gas or Electric Heating ............................................................................................................. 25 Wiring Diagrams ....................................................................................................................... 27 Condensate Drain Pan ............................................................................................................... 27

Installation..................................................................................................................................... 27 Locating Units ........................................................................................................................... 27 Setting the Curb ........................................................................................................................ 29 Forklifting the Unit (6-25 and 30 ton) ...................................................................................... 30 Lifting the Unit ......................................................................................................................... 30 Duct Connection ....................................................................................................................... 34 Seismic Curb Installation .......................................................................................................... 35 Outside Air Rain Hood ............................................................................................................. 39 Metal Mesh Filters (6-25 and 30 ton Units) .............................................................................. 40 Electrical ................................................................................................................................... 41

Variable Speed Compressors ................................................................................................ 43 Thermostat Control Wiring ................................................................................................... 44

Gas Heating ............................................................................................................................... 45 Piping Sizing Examples ........................................................................................................ 46 Inlet and Manifold Pressures ................................................................................................ 47 Gas Pressure Regulator & Overpressure Protection Device ................................................. 47 Piping Supports ..................................................................................................................... 47 Additional Gas Piping Considerations .................................................................................. 47 Leak Testing.......................................................................................................................... 49

Refrigerant-to-Water Heat Exchanger ...................................................................................... 49 Open Loop Applications ....................................................................................................... 49 Freezing Water in the Heat Exchanger ................................................................................. 50 Water Piping ......................................................................................................................... 51

Condensate Drain Piping .......................................................................................................... 53 Heating Coils ............................................................................................................................ 53 Chilled Water Coil .................................................................................................................... 54

Startup ........................................................................................................................................... 55 Supply Fans ............................................................................................................................... 55 Power Return Axial Flow Fans ................................................................................................. 56 (16-25 and 30 tons) ................................................................................................................... 56 Power Return and Exhaust Axial Flow Fans (26 and 31-140 tons) .......................................... 58 Filters ........................................................................................................................................ 59 Adjusting Refrigerant Charge ................................................................................................... 59

Checking Liquid Sub-Cooling .............................................................................................. 60 Checking Evaporator Superheat ........................................................................................... 60

4

Adjusting Sub-cooling and Superheat Temperatures ........................................................... 61 Gas Heater Startup .................................................................................................................... 63 Condenser Fan Electronically Commutated Motor (ECM) Startup ......................................... 64 VFD Controlled Condenser Fan Startup ................................................................................... 65

Operation....................................................................................................................................... 65 Thermostat Operation ............................................................................................................... 65 Packaged DX Cooling Operation and Control .......................................................................... 65 Gas Heater Operation ................................................................................................................ 66 Electric Heating Operation ....................................................................................................... 66 Steam or Hot Water Preheating and Heating Operation ........................................................... 66 Chilled Water or Non-Compressorized DX Cooling Operation ............................................... 66

Maintenance .................................................................................................................................. 67 Gas Heating ............................................................................................................................... 67 Gas Heat Exchanger Removal .................................................................................................. 68 DX Cooling ............................................................................................................................... 68 Condenser Fans (6-25 and 30 ton) ............................................................................................ 69 Condensate Drain Pans ............................................................................................................. 69 Evaporator Coil (6-25 and 30 ton) ............................................................................................ 70 Brazed Plate Heat Exchanger Cleaning .................................................................................... 70 E-Coated Coil Cleaning ............................................................................................................ 71 Supply Fans ..........................................................................................