Aaon CN-140 Manuel d'utilisateur

CN Series Condensing Units Installation, Operation, & Maintenance If the information in this ma

CN Series Feature String Nomenclature Model Options : Unit Feature Options GEN MJREV SIZE SERIES MNREV VLT A1 A2 A3 A4 A5 1 2A 2B 3A 3B 4 5

CN Series Feature String Nomenclature Model Options : Unit Feature Options GEN MJREV SIZE SERIES MNREV VLT A1 A2 A3 A4 A5 1 2A 2B 3A 3B 4 5

12 General Information AAON CN Series condensing units are complete air-cooled condensing units ranging from 55 to 140 tons of cool

13 Failure to observe the following instructions will result in premature failure of your system, and possible voiding of

14 Compressor life will be seriously shortened by reduced lubrication, and the pumping of excessive amounts of liquid oil and liquid refriger

15 Installation Unit Placement The AAON CN Series is designed for outdoor applications and mounting at ground level or on a rooftop

16 Figure 1 - Curb Mounting with Dimensions Figure 2 - Steel Mounting Rail with Dimensions Figure 3 - Concrete Pad Mounting with Dimensions L

17 the flashings must be installed on each end of the unit to complete the finished seal at the base. The flashings are unit specific and designed

18 Mounting Isolation For roof mounted applications or anytime vibration transmission is a factor, full perimeter vibration

19 reducing installation costs, and reducing the potential for leakage. However, as pipe diameters narrow, pressure-reducing frictional forc

20 may provide additional sub-cooling to the refrigerant. When routing the liquid line through high temperature areas, insulation of the

21 sized to return oil at minimum load, while the larger diameter pipe should be sized so that flow through both pipes provides acceptable pre

22 Hot Gas Bypass Piping Considerations for Evaporator Below Condensing Unit The line must slope downward from the HGB valve toward the eva

23 LAC Valve The LAC valve is a non-adjustable three way valve that modulates to maintain receiver pressure. As the receiver pressu

24 Condenser Flooding In order to maintain head pressure in the refrigeration system, liquid refrigerant is backed up in the condens

25 Figure 8 - Terminal Block Startup technician must check for proper motor rotation and check fan motor amperage listed on the mot

26 Startup (See back of the manual for startup form) Before the startup of the condensing unit be sure that the following i

27 2. Determine the direction of rotation Right, R, is clockwise when facing the discharge side of the fan and Left, L, is counterc

28 6. Determine the current blade pitch and the pin location for the new blades Table 3 - Condenser Fan Pin Location Type Bushing Mount Blade Pi

29 Fan Assembly Bushings The fan assembly bushings should be tightened to the specifications listed in the following table. Table 5 - Fan

3 Table of Contents Safety ...

30 Maintenance General Qualified technicians must perform routine service checks and maintenance. This includes reading and recording the

31 For units equipped with low ambient (0°F) option see the special charging instructions at the end of this section. Checking Liquid Sub-cooling

32 The system is undercharged if the superheat is too high and the sub-cooling is too low. Correct an undercharged system by adding refrigerant t

33 Table 8 - R-410A Refrigerant Temperature-Pressure Chart °F PSIG °F PSIG °F PSIG °F PSIG °F PSIG 20 78.3 47 134.7 74 213.7 101 321.0 128 463.2 2

34 Lubrication All original motors and bearings are furnished with an original factory charge of lubrication. Air-Cooled Condenser The air-

35 Microchannel Coil Cleaning Documented routine cleaning of microchannel coils with factory provided e-coating is required to

36 Refrigerant Piping Diagrams Figure 14 - A/C Only Piping, AHU Above CU

37 Figure 15 - A/C Only Piping, AHU Below CU

38 Figure 16 - Modulating Hot Gas Reheat Piping, AHU Above CU

39 Figure 17 - Modulating Hot Gas Reheat Piping, AHU Below CU

4 Index of Tables and Figures Tables: Table 1 - Service Clearances...

40 Figure 18 - Hot Gas Bypass Piping, AHU Above CU

41 Figure 19 - Hot Gas Bypass Piping, AHU Below CU

42 Figure 20 - Modulating Hot Gas Reheat with Hot Gas Bypass Piping, AHU Above CU

43 Figure 21 - Modulating Hot Gas Reheat with Hot Gas Bypass Piping, AHU Below CU

44 CN Series Startup Form Job Name:_______________________________________________ Date:______________ Address:________________________________

45 Compressors/DX Cooling Check Rotation Number Model # L1 L2 L3 Head Pressure PSIG Suction Pressure PSIG Crankcase Heater Amps 1 2

46 Condenser Fans Alignment Check Rotation Nameplate Amps________ Number hp L1 L2 L3 1 2 3 4 5 6 7 8

47 Maintenance Log This log must be kept with the unit. It is the responsibility of the owner and/or maintenance/service contractor t

48 Literature Change History March 2014 Initial version.

5 Safety ELECTRIC SHOCK, FIRE OR EXPLOSION HAZARD Fail

AAON 2425 South Yukon Ave. Tulsa, OK 74107-2728 Phone: 918-583-2266 Fax: 918-583-6094 www.aaon.com CN Series Installation, Operation, & Ma

6 FIRE, EXPLOSION OR CARBON MONOXIDE POISONING HAZ

7 PVC (Polyvinyl Chloride) and CPVC (Chlorinated Pol

8 1. Startup and service must be performed by a Factory Trained Service Technician 2. The uni

CN Series Feature String Nomenclature Model Options : Unit Feature Options GEN MJREV SIZE SERIES MNREV VLT A1 A2 A3 A4 A5 1 2A 2B 3A 3B 4 5