Summary of the content on the page No. 1
38AKS028-044
Air-Cooled Condensing Units
50/60 Hz
Installation, Start-Up and
Service Instructions
CONTENTS
Page
SAFETY CONSIDERATIONS
SAFETY CONSIDERATIONS...................1 Installing,startingup,andservicingair-conditioningequip-
ment can be hazardous due to system pressures, electrical
BEFORE INSTALLATION .....................1-3
components, and equipment location (roofs, elevated struc-
Rigging......................................1
tures, etc.).
Placing Unit ...............................
Summary of the content on the page No. 2
Table 1A — Physical Data — English UNIT 38AKS 028 034 044 COMPRESSOR Reciprocating Semi-Hermetic No. ...Type 1...06E9265 1...06E9275 1...06E9299 No. Cyls (ea)...Speed, Rpm (60/50 Hz) 6...1750/1460 Capacity Steps 3 Oil Charge*, Pt 20.0 20.0 19.0 Oil Pressure Switch (psi) Set Points — Cutout 6 6 2 Differential — Cut-in 14 Max. Crankcase Heater (watts) 180 Protection See Note Capacity Control (Psig) Suction Pressure Unloader(s) No. 1 Unloader Settings Load 76 76 76 Unload 58 58 58 No. 2 Unloader Se
Summary of the content on the page No. 3
PlacingUnit— There must be 4 ft (1220 mm) for ser- vice on all sides of unit, and a minimum of 8 ft (2440 mm) clear air space above unit. For multiple units, allow 8 ft (2440mm)separationbetweenunitsforairflowandservice. MountingUnit— Whenunitisinproperlocation,use ofmountingholesinbaserailsisrecommendedforsecuring unit to supporting structure or for mounting unit on vibra- tion isolators, if required. Fasteners for mounting unit are field supplied. Be sure to mount unit level to ensure proper oil
Summary of the content on the page No. 4
NOTE:All dimensions are in inches (mm). Fig. 3 — Compressor Mounting Receiver— No receiver is provided with the unit; it is recommended that onenot be used. PipingProcedure— Donotremoverun-aroundpipe from suction and liquid line stubs until piping connections arereadytobemade.Passnitrogenorotherinertgasthrough pipingwhilebrazing,topreventformationofcopperoxide. Installfield-suppliedthermostaticexpansionvalve(TXV) in liquid line ahead of each evaporator section. For 2-stage cooling,thefield-supplie
Summary of the content on the page No. 5
Table 2A — Refrigerant Piping Sizes — 60 Hz SINGLE SUCTION RISERS LENGTH OF INTERCONNECTING PIPING, FT (M) UNIT 16-25 (4.9-7.6) 26-50 (7.9-15.2) 51-75 (15.5-22.8) 76-100 (23.2-30.5) 101-200 (30.8-60.9) 38AKS LSL S L S L S L S 7 5 7 1 7 1 7 1 7 1 028 ⁄8 1 ⁄8 ⁄8 2 ⁄8* ⁄8 2 ⁄8* ⁄8 2 ⁄8* ⁄8 2 ⁄8* 7 1 7 1 7 1 1 1 1 5 034 ⁄8 2 ⁄8 ⁄8 2 ⁄8 ⁄8 2 ⁄8 1 ⁄8 2 ⁄8 1 ⁄8 2 ⁄8* 7 1 7 1 1 5 1 5 1 5 044 ⁄8 2 ⁄8 ⁄8 2 ⁄8 1 ⁄8 2 ⁄8*1⁄8 2⁄8*1⁄8 2⁄8* L— Liquid Line S— Suction Line *IMPORTANT — Requires a double suction
Summary of the content on the page No. 6
closedtopreventanexcessiveaccumulationofrefriger- PowerSupply— Electricalcharacteristicsofavailable antinthecompressoroil. powersupplymustagreewithunitnameplaterating.Supply voltage must be within limits shown in Table 3. 3. Power entry is one end only. 4. Maximum field wire sizes allowed by lugs on terminal IMPORTANT:Operatingunitonimpropersupplyvolt- block are: age,orwithexcessivephaseimbalance,constitutesabuse andmayaffectCarrierwarranty.SeeUnbalanced3-Phase UNIT WIRE V-Ph-Hz 38AKS SIZE* Suppl
Summary of the content on the page No. 7
FIELD CONNECTIONS UNBALANCED 3-PHASE SUPPLYVOLTAGE — Never operate a motor where a phase imbalance in supply voltage 1. Main Power — Bring wires from the fused disconnect is greater than 2%. Use the following formula to determine switch through hole in bottom rail of unit to control box the percent voltage imbalance: 11 12 (Fig. 6 and 7) and connect terminals , , and % Voltage Imbalance 13 line side of terminal blockTB1 (see Fig. 8 and 9A max voltage deviation from average voltage = 100 x or9B).
Summary of the content on the page No. 8
LEGEND NEC — National Electrical Code VAV — VariableAir Volume NOTES: 1. Theremustbeminimum(2440mm)8ft.clearairspaceabove unit. 2. The approximate operating weight of the unit is: 50 AND 60 HZ WT WT UNIT (Lb) (Kg) 38AKS028 1650 748 38AKS028C 1804 818 38AKS034 1803 818 38AKS034C 2009 911 3. A‘‘C’’inthemodelnumberindicatesunithasfactory-installed copper coil. Fig. 6 — Dimensional Drawing, 38AKS028,034 8
Summary of the content on the page No. 9
LEGEND NEC — National Electrical Code NOTES: 1. Theremustbeminimum(2440mm)8ft.clearairspaceabove unit. 2. The approximate operating weight of the unit is: 50 HZ AND 60 HZ WT WT UNIT (Lb) (Kg) 38AKS044 2437 1106 38AKS044C 2745 1246 3. A‘‘C’’inthemodelnumberindicatesunithasfactory-installed copper coil. Fig. 7 — Dimensional Drawing, 38AKS044 9
Summary of the content on the page No. 10
10 LEGEND NOTES: 1.FactorywiringinaccordancewiththeNEC.Anyfield AFS — Airflow Switch modifications or additions must be in compliance CB — Circuit Breaker with all applicable codes. EQUIP — Equipment 2.Allfieldinterlockcontactsmusthaveminimumrat- FU — Fuse ing of 180 va pilot duty plus capacity required for GND — Ground field-installed equipment. All field interlock con- LLS1 — Liquid Line Solenoid for tactsinthe24-vcontrolcircuitmusthaveminimum Solenoid Drop Control ratingof70vapilotdutypluscapacity
Summary of the content on the page No. 11
11 LEGEND BPR — Bypass Relay FM — Fan Motor C— Contactor, Compressor FU — Fuse DB — Circuit Breaker GND — Ground CR — Control Relay LLSV — Liquid Line Solenoid Valve CM — Control Module NEC — National Electrical Code (U.S.A.) EQUIP — Equipment TB — Terminal Block FC — Fan Contactor TRAN — Transformer Fig. 9A — Component Arrangement — 60 Hz
Summary of the content on the page No. 12
12 LEGEND BPR — Bypass Relay C— Contactor, Compressor CB — Circuit Breaker CR — Control Relay CM — Control Module EQUIP — Equipment FC — Fan Contactor FM — Fan Motor FU — Fuse GND — Ground LLSV — Liquid Line Solenoid Valve NEC — National Electrical Code (U.S.A.) TB — Terminal Block TDR — Time Delay Relay TRAN — Transformer Fig. 9B — Component Arrangement — 50 Hz
Summary of the content on the page No. 13
Thestart-upofthecompressorcanoccurbetween3seconds START-UP and approximately 5 minutes from the time the control cir- Initial Check cuit is energized due to the anti-short cycle feature of the control module (CM). ChargeSystem— Actualstart-upshouldbedoneonly Do not attempt to start the condensing unit, even mo- undersupervisionofaqualifiedrefrigerationmechanic.Re- mentarily, until the following steps have been com- fer to charging charts. pleted. Compressor damage may result. SeeFig.10-12forthepa
Summary of the content on the page No. 14
14 Fig. 10 — 38AKS028 Charging Chart, 50/60 Hz
Summary of the content on the page No. 15
15 Fig. 11 — 38AKS034 Charging Chart, 50/60 Hz
Summary of the content on the page No. 16
16 Fig. 12 — 38AKS044 Charging Chart, 50/60 Hz
Summary of the content on the page No. 17
FORSERVICINGONLY—Tospeedupthe5-minuteanti- Complete Unit Stoppage shortcycle,atemporaryjumpermaybeplacedbetweenter- CAUSES—Interruptionofsuppliedpower,compressorover- minals T1 and T6 of the control module. temperature protection, or open HPS causes compressor stoppage. RESTART — The unit recycles and restarts automatically This jumper must be removed after servicing is com- undertheCMwhenpowerisrestored.StoppagebyHPS,or plete. Failure to remove this jumper is considered abu- compressor circuit
Summary of the content on the page No. 18
TRAN1 CM CR1 FC2 FC3 FC C1 CB2 CB1 TRAN2 TB3 TB2 COMPRESSOR ENDAND RIGHT-SIDE VIEW COMPRESSOR END, CONTROL PANEL REMOVED LIQUID LINE SERVICE VALVE COMPRESSOR END, RIGHT-SIDEACCESS DOOR OIL PRESSURE SAFETY SWITCH COMPRESSOR END, LEFT-SIDEACCESS DOOR (JUNCTION BOX COVER REMOVED) Fig. 13 — 38AKS Unit with Access Panels Removed 18
Summary of the content on the page No. 19
FanAdjustment — Adjust fan as shown in Fig. 14. CapacityControl— Capacity control is by 2 suction pressure actuated unloaders. Each controls 2 cylinders. Un- loadersarefactoryset(seeTable1Aor1B)butmaybefield adjusted. Number 1 unloader is on cylinder bank on same side of compressor as terminal box. CONTROLSET POINT — The control set point (cylinder load point) is adjustable from 0 to 85 psig (0 to 586 kPag). Toadjust,turncontrolsetpointadjustmentnut(Fig.15)clock- wise to its bottom stop. In this
Summary of the content on the page No. 20
OilPressureSafetySwitch(OPS)— TheOPSin Head Pressure Control — Control maintains ad- the control circuit stops the compressor and unit, if proper equatedischargepressureunderlowambienttemperaturecon- oilpressuredifferentialisnotestablishedatstart-upormain- ditions. See Table 5. tainedduringoperation.IfOPSstopstheunit,determinethe FAN CYCLING —These 38AKS units have standard pro- causeandcorrectbeforerestartingunit.Failuretodosowill visionforfullyautomaticintermediate-seasonheadpressure constitut
