Carrier Air Conditioner Pressure Switch Settings Psig kPa, Switch Cutout CUT-IN, 30GTN,R Units

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Safety Devices — Chillers contain many safety devices and protection logic built into electronic control. Following is a brief summary of major safeties.

COMPRESSOR PROTECTION

Circuit Breaker — One manual-reset, calibrated-trip magnetic circuit breaker for each compressor protects against overcur- rent. Do not bypass or increase size of a breaker to correct problems. Determine cause for trouble and correct before resetting breaker. Circuit breaker must-trip amps (MTA) are listed on individual circuit breakers, and on unit label diagrams.

30GTN,R and 30GUN,R070 (50 Hz), 080-110 and 230B- 315B Compressor Protection Board (CPCS) — The CPCS is used to control and protect compressors and crankcase heaters. Board provides following features:

compressor contactor control

crankcase heater control

ground current protection

status communication to processor board

high-pressure protection

One large relay is located on CPCS that controls crankcase heater and compressor contactor. In addition, this relay pro- vides a set of contacts that the microprocessor monitors to de- termine operating status of compressor. If the MBB determines that compressor is not operating properly through signal con- tacts, control locks compressor off.

The CPCS contains logic that can detect if current-to- ground of any winding exceeds 2.5 amps; if so, compressor shuts down.

A high-pressure switch with a trip pressure of 426 ± 7 psig (2936 ± 48 kPa) is mounted on each compressor; switch setting is shown in Table 34. Switch is wired in series with the CPCS. If switch opens, CPCS relay opens, processor detects it through signal contacts, and compressor locks off. A loss-of-charge switch is also wired in series with the high-pressure switch and CPCS.

If any of these switches opens during operation, the com- pressor stops and the failure is detected by the MBB when sig- nal contacts open. If lead compressor in either circuit is shut down by high-pressure switch, ground current protector, loss of charge switch, or oil pressure switch, all compressors in the cir- cuit are locked off.

30GTN,R and 30GUN,R 130-210,230A-315A and 330A/B-420A/B — A control relay in conjunction with a ground fault module replaces the function of the CPCS (above). To reset, press the push-button switch (near the Mar- quee display).

Table 34 — Pressure Switch Settings,

psig (kPa)

SWITCH

CUTOUT

CUT-IN

High Pressure

426

± 7

320

± 20

30GTN,R Units

(2936

± 48)

(2205

± 138)

High Pressure

280 ± 10

180

± 20

30GUN,R Units

(1830

± 69)

(1240

± 138)

Loss-of-Charge

7 (48.2)

22 (151.6)

LOW OIL PRESSURE PROTECTION — Lead

compres-

sor in each circuit is equipped with a switch to detect low oil pressure. Switch is connected directly to processor board. Switch is set to open at approximately 5 psig (35 kPa) and to close at 9 psig (62 kPa) maximum. If switch opens when compressor is running, CR or processor board stops all com- pressors in circuit. During start-up, switch is bypassed for 2 minutes.

CRANKCASE HEATERS — Each compressor has a 180-w crankcase heater to prevent absorption of liquid refrigerant by oil in crankcase when compressor is not running. Heater power

source is auxiliary control power, independent of main unit power. This assures compressor protection even when main unit power disconnect switch is off.

IMPORTANT: Never open any switch or disconnect that deenergizes crankcase heaters unless unit is being serviced or is to be shut down for a prolonged period. After a prolonged shutdown or service, energize crank- case heaters for 24 hours before starting unit.

COOLER PROTECTION

Freeze Protection — Cooler can be wrapped with heater cables as shown in Fig. 34, which are wired through an ambi- ent temperature switch set at 36 F (2 C). Entire cooler is cov- ered with closed-cell insulation applied over heater cables. Heaters plus insulation protect cooler against low ambient tem- perature freeze-up to 0° F (–18 C).

IMPORTANT: If unit is installed in an area where ambi- ent temperatures fall below 32 F (0° C), it is recom- mended that inhibited ethylene glycol or other suitable corrosion-inhibitive antifreeze solution be used in chilled-liquid circuit.

Low Fluid Temperature — Main Base Board is programmed to shut chiller down if leaving fluid temperature drops below 34 F (1.1 C) for water or more than 8° F (4.4° C) below set point for brine units. The unit will shut down without a pumpout. When fluid temperature rises to 6° F (3.3° C) above leaving fluid set point, safety resets and chiller restarts. Reset is automatic as long as this is the first occurrence.

Loss of Fluid Flow Protection — Main Base Board contains internal logic that protects cooler against loss of cooler flow. Entering and leaving fluid temperature sensors in cooler detect a no-flow condition. Leaving sensor is located in leaving fluid nozzle and entering sensor is located in first cooler baffle space in close proximity to cooler tubes, as shown in Fig. 34. When there is no cooler flow and the compressors start, leaving fluid temperature does not change. However, entering fluid temper- ature drops rapidly as refrigerant enters cooler through EXV. Entering sensor detects this temperature drop and when enter- ing temperature is 3° F (1.6° C) below leaving temperature, unit stops and is locked off.

Loss-of-Charge — A pressure switch connected to high side of each refrigerant circuit protects against total loss-of-charge. Switch settings are listed in Table 34. If switch is open, unit cannot start; if it opens during operation, unit locks out and cannot restart until switch is closed. Low charge is also moni- tored by the processor when an EXV is used. The loss-of- charge switch is wired in series with the high-pressure switch on each circuit’s lead compressor.

LEGEND

T — Thermistor

Fig. 34 — Cooler Heater Cables

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Contents Safety Considerations ContentsGeneral ContentsIntroduction Major System Components Unit Sizes and Modular Combinations 30GTN,RUnit Sizes and Modular Combinations 30GUN,R Unit Nominal Section a Section B 30GTN,R Tons Unit 30GTN,RCarrier Comfort Network CCN Interface Control Module CommunicationThermistor Designations Status Switches Output RelayPage 24 V Control Schematic, Unit Sizes 24 V Control Schematic, Unit Sizes 080-110, 230B-315B CCN LEN Data Communication Port Main Base Board Operating Data 040-110 130-210Thermistor T3 and T4 Locations Compressor Thermistor Locations T7 and T8 Regular Wiring Plenum Wiring Alpha 1895 American ManufacturerBelden 8205 Columbia D6451 Manhattan M13402 M64430 Quabik 6130Compressor Protection Control System Module Sizes Stepper Motor 12 VDC CEPL130351 Part Load Data Percent Displacement, Standard Units Displacement Compressors30GUN,R Approx110, 290B 255A 60 Hz330A/B 360B 50 Hz390B 60 Hz 390B 50 HzB1† A1,B1 A1†,A2,B1 A1*,B1†,B2 Unloaded compressor Two unloaders, both unloaded 170, 270A 190, 290A, 360A/BA1*,B1*,B2 Required Hardware for Additional Unloaders 150-210Head Pressure Control PumpoutPower FAN Arrangement FAN Relay Normal ControlService Test See Both main power Scrolling Marquee DisplayModes GEN.O TestRun Status Mode and Sub-Mode Directory SUB-MODE Keypad Range Item Expansion Comment Entry ViewStrt VersSUB-MODE Keypad Range Item Expansion Comment Entry Test Service Test Mode and Sub-Mode DirectoryOuts Pressure Mode and Sub-Mode Directory Temperature Mode and Sub-Mode DirectorySet Point Mode and Sub-Mode Directory Inputs Mode and Sub-Mode Directory Reading and Changing Chilled Fluid Set PointSUB-MODE Keypad Range Item Expansion Comment Entry GEN.I CrctConfiguration Mode and Sub-Mode Directory Outputs Mode and Sub-Mode DirectorySUB-MODE Keypad Range Item Expansion Comment Entry GEN.O OPT1 OPT2CCN EMM240 RsetExample of Temperature Reset Return Fluid Configuration SUB-MODE Keypad Display Item Expansion Comment Entry RsetExample of Configuring Dual Chiller Control Slave Chiller Example of Configuring Dual Chiller Control Master ChillerSUB-MODE Keypad Entry Display Item Expansion Comment Rset Example of Compressor Lead/Lag Configuration Time Clock Mode and Sub-Mode DirectorySUB-MODE Keypad Display Item Expansion Comment Entry OPT2 SUB-MODE Keypad Entry Item Expansion Comment Range TimeSetting an Occupied Time Schedule Operating Mode and Sub-Mode DirectoryMode no Item Expansion Description Operating ModesAlarms Mode and Sub-Mode Directory Example of Reading and Clearing AlarmsConfiguring Temperature Reset Mode Keypad SUB-MODEConfiguration Entry ExpansionRED LED Entry Expansion Configuration Configuring Demand Limit DLS2Troubleshooting To 20 mA Demand LimitingPage Alarm and Alert Codes T051By Control Method Cause Code Alert GENERATED? EWTFSM LCWT153 T155T170 T173T203 T204T205 T206Service Electronic ComponentsOil Charge Compressor OIL RequiredCooler Thermistor Locations Plugs Components for Part Number PluggingCondenser Coils Cooler Head Bolt Tightening Sequence Typical Tube SheetCondenser Fan Adjustment Hz Low Noise Fan Option Units Dimension FAN TypePrinted Circuit Board Connector Refrigerant Feed Components Each circuit hasThermistors Temperature Sensors Drop B 5K Thermistor Temperature F vs Resistance/VoltageDrop a 5K Thermistor Temperature C vs Resistance/Voltage Temp Voltage Resistance Drop 200,510 Pressure Switch Settings Psig kPa Switch Cutout CUT-IN30GTN,R Units 30GUN,R UnitsPRE-START-UP System CheckTemperature Limits for Standard Units TemperatureMaximum Ambient Temperature 125 START-UP and OperationRefrigerant Circuit Field WiringNominal and Minimum Cooler Fluid Flow Rates CWP ALMHgbps Energy Management Module EMM Wiring Compressor Expansion Board CXB Accessory Wiring Unit Configuration Settings OPTIONS1 Options ConfigurationDescription Status Default Units Point Description Status Default PointAlarmdef Alarm Definition Table OPTIONS2 Options ConfigurationAppendix a CCN Tables Resetcon Temperature Reset and Demand Limit Brodefs Broadcast POC Definition TableAunit General Unit Parameters Circaan Circuit a Analog ParametersCircadio Circuit a Discrete Parameters Description Status Units Point ForceableCircban Circuit B Analog Parameters Circbdio Circuit B Discrete ParametersOptions Unit Parameters Strthour Description Status Units PointDescription Status Units Point Defaults CurrmodsLine Description Point CSM/FSM Equipment Table Type 621H, BlockDescription Status Point Appendix B Fluid Drop Pressure Curves Cooler Fluid Pressure Drop Curves 30GUN,GUR040-110Cooler Fluid Pressure Drop Curves 30GUN,GUR130-210 Appendix B Fluid Drop Pressure CurvesCooler Pressure Drop KEY Appendix B Fluid Drop Pressure Curves Cooler Fluid Pressure Drop Curves 30GUN,GUR230B-315B Cooler Fluid Pressure Drop Curves 30GTN,GTR040-110 Cooler Fluid Pressure Drop Curves 30GTN,GTR130-210 Appendix B Fluid Drop Pressure Curves Module B 30GTN,GTR230,245 Module B 30GTN,GTR255,290,315 Service Training Call for Free CatalogRemove and use for job file Preliminary Information START-UP Checklist for Comfortlink Chiller SystemsEquipment Chiller Model no Preliminary Equipment Check Check box if complete System Fluid Volume in Loop Type System UnitStart-UpUnit Start-Up Description Status Units Value Ctrl CcnaCcnb BaudSlct Heating Cooling Setpoint Select CND.P RMT.A All Units

Air Conditioner specifications

Carrier Air Conditioners have long been synonymous with reliability and innovation in climate control. Founded by Willis Carrier, the inventor of modern air conditioning, the brand has continuously set industry standards through state-of-the-art technologies and features designed to enhance indoor comfort.

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In conclusion, Carrier air conditioners represent a perfect blend of cutting-edge technology, energy efficiency, and user comfort. Their emphasis on sustainability and smart features positions them as a leading choice for homeowners seeking reliable and innovative climate control solutions. Whether for cooling a small room or an entire house, Carrier remains a trusted name in air conditioning.