Bryant R-22 service manual Pressure Switches, Personal Injury Hazard

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Pressure Switches

Pressure switches are protective devices wired into control circuit (low voltage). They shut off compressor if abnormally high or low pressures are present in the refrigeration circuit. Puron pressure switches are specifically designed to operate with Puronr systems. R-22 pressure switches must not be used as replacements for the Puronr air conditioner or heat pump. Puronr pressure switches are identified by a pink stripe down each wire.

Low-Pressure Switch (AC Only)

The low-pressure switch is located on suction line and protects against low suction pressures caused by such events as loss of charge, low airflow across indoor coil, dirty filters, etc. It opens on a pressure drop at about 50 psig for Puron and about 27 for R22. If system pressure is above this, switch should be closed. To check switch:

1.Turn off all power to unit.

2.Disconnect leads on switch.

3.Apply ohmmeter leads across switch. You should have continuity on a good switch.

NOTE: Because these switches are attached to refrigeration system under pressure, it is not advisable to remove this device for troubleshooting unless you are reasonably certain that a problem exists. If switch must be removed, remove and recover all system charge so that pressure gages read 0 psi. Never open system without breaking vacuum with dry nitrogen.

!CAUTION

PERSONAL INJURY HAZARD

Failure to follow this caution may result in personal injury.

Wear safety glasses, protective clothing, and gloves when handling refrigerant.

To replace switch:

1. Apply heat with torch to solder joint and remove switch.

!CAUTION

PERSONAL INJURY HAZARD

Failure to follow this caution may result in personal injury.

Wear safety glasses when using torch. Have quenching cloth available. Oil vapor in line may ignite when switch is removed.

2.Braze in 1/4-in. flare fitting and screw on replacement pressure switch.

High-Pressure Switch (AC & HP)

The high-pressure switch is located in liquid line and protects against excessive condenser coil pressure. It opens around 610 or 670 psig for Puron and 400 psig for R22 (+/- 10 for both). Switches close at 298 (+/- 20) psig for R-22 and 420 or 470 (+/-

25)psig for Puron. High pressure may be caused by a dirty condenser coil, failed fan motor, or condenser air re-circulation. To check switch:

1.Turn off all power to unit.

2.Disconnect leads on switch.

3.Apply ohmmeter leads across switch. You should have continuity on a good switch.

NOTE: Because these switches are attached to refrigeration system under pressure, it is not advisable to remove this device for troubleshooting unless you are reasonably certain that a problem exists. If switch must be removed, remove and recover all system charge so that pressure gauges read 0 psi. Never open system without breaking vacuum with dry nitrogen.

!CAUTION

PERSONAL INJURY HAZARD

Failure to follow this caution may result in personal injury.

Wear safety glasses, protective clothing, and gloves when handling refrigerant.

To replace switch:

1. Apply heat with torch to solder joint and remove switch.

!CAUTION

PERSONAL INJURY HAZARD

Failure to follow this caution may result in personal injury.

Wear safety glasses when using torch. Have quenching cloth available. Oil vapor in line may ignite when switch is removed.

2.Braze in 1/4-in. flare fitting and replace pressure switch.

Loss of Charge Switch (HP Only)

Located on liquid line of heat pump only, the liquid line pressure switch functions similar to conventional low-pressure switch.

Because heat pumps experience very low suction pressures during normal system operation, a conventional low-pressure switch cannot be installed on suction line. This switch is installed in liquid line instead and acts as loss-of-charge protector. The liquid-line is the low side of the system in heating mode. It operates identically to low-pressure switch except it opens at 23 (+/- 5) psig for Puron and 7 (+/- 5) psig for R22 and closes at 55 (+/- 5) psig for Puron and 22 (+/- 5) for R22 Two-stage heat pumps have the low-pressure switch located on the suction line. The two-stage control board has the capability to ignore low-pressure switch trips during transitional (defrost) operation to avoid nuisance trips. Troubleshooting and removing this switch is identical to procedures used on other switches. Observe same safety precautions.

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Contents Table of Contents Application GuidelineAIR Conditioner and Heat Pump Model Number Nomenclature Table of Contents TWO Stage NON-COMMUNICATINGTWO Stage Communicating Serial Number NomenclatureIntroduction Safety ConsiderationsInstallation Guideline Required Field-Installed Accessories for Heat Pumps AccessoriesRequired Field-Installed Accessories for Air Conditioners Accessory Descriptions Base / Mid-Tier / Deluxe 4-sided Baffle Assembly LOW-AMBIENT Cooling GuidelineDeluxe 3-sided Baffle Assembly and Dimensions Basic Cabinet Designs Cabinet AssemblyLong Line Guideline Access Compressor Or Other Internal Cabinet Components Legacy RNC and Legacy Line Control Box Identification Labeling Figure LabelsContactor Aluminum WireElectrical CapacitorCycle Protector Time-Delay RelayCrankcase Heater Pressure Switches Personal Injury HazardDefrost Thermostat Defrost Control BoardIf defrost thermostat is stuck closed Troubleshooting HK32EA001 If outdoor unit will not runDefrost Speedup If defrost thermostat is stuck openCooling Five-Minute Compressor DelayQuiet Shift HeatingCompressor Plug Troubleshooting HK32EA003Fan Motor Low-Voltage TerminalsLocked Rotor Compressor FailuresMechanical Failures Runs, Does Not PumpNoisy Compressor Split Post Grommet part number KA75UG100Unit Personal Injury Hazard Single-Phase MotorsElectrical Failures Compressor Oil Refrigeration SystemRefrigerant Brazing Synthetic Roof Precautionary ProcedureServicing Systems on Roofs With Synthetic Materials Oil ChargingPersonal Injury and Unit Damage Hazard Service Valves and PumpdownPumpdown Procedure Heating Piston AccuRaterr Heat Pumps Only AccuRaterr Components Used in R-22 Heat PumpsReversing Valve Reversing Valve Heating Mode, Solenoid De-EnergizedSuction Line Filter Drier Install Liquid-line Filter Drier Indoor ACLiquid Line Filter Drier Accumulator AccumulatorTXV Operation Install TXVThermostatic Expansion Valve TXV Unit Operation HazardReplacing TXV on Indoor Coil post-2006 Make Piping ConnectionsReplacing TXV on an Indoor Coil pre-2006 Personal Injury and Environmental HazardCoil Removal Refrigeration System RepairLeak Detection Fire HazardCompressor Removal and Replacement System Clean-Up After BurnoutDeep Vacuum Method Check ChargeEvacuation Low Superheat with Normal or Low Suction Pressure Troubleshooting with SuperheatBasic Diagnostics Low Superheat with High Suction PressurePseudo Evaporator Superheat Instructions High Superheat with Normal or High Suction PressureHunting Superheat Puron System Suction Pressure Drop Example22 System Suction Pressure Drop PuronrRefrigerant Pressure Temperature Chart Psig22 Refrigerant Pressure Temperature Relationship PsigPuron Subcooling Chart Liquid Line Temperature F Liq Press Subcooling F PsigPuron Superheat Chart Superheat F Psig22 Subcooling Chart Liquid Line Temperature F PT F Subcooling F Pres Psig22 Superheat Chart Model Plug TWO-STAGEApplication Guidelines Model Plug InformationDefrost General InformationLow Ambient Cooling Airflow Selection for 315AAV/355AAV FurnacesForced Defrost Liquid-Line Solenoid AccessoryDefrost Hold All 286A units must be charged in high stage onlyUtility Interface With Evolution Control One Minute Stage Change Time Delay on 286ANA/187ANA ModelsCooling and Heating Operation Compressor Operation on 286ANA/187ANA ModelsECM Fan Motor Troubleshooting Outdoor Fan Motor OperationThermistors Time DelaysMuffler, Accumulator, Reversing Valve RVS Control BOX Troubleshooting Compressor Voltage Sensing 230V Line Power Disconnect Detection230v Brown-Out Protection Defeated Contactor Shorted DetectionFailed Thermistor Default Operation Unloader Test ProcedureTemperature Thermistors Thermistor Sensor ComparisonTroubleshooting Status CodesEdge Thermidistat Models T6-PRH-01 or T6-NRH-01 TWO-STAGE 286B/289B/180B/187B General Information Heating Check Chart Procedure All 286B units must be charged in high stage onlyCompressor Operation on 289B/180B Models Low Stage High Stage Low & High Model Control Box Incoming PowerTroubleshooting 187B & 286B Start Circuit Contactor And CapacitorTroubleshooting HK38EA015 circuit board 286B Models Compressor Thermal Cutout 289B Compressor Thermal CutoutOutdoor Coil Thermistor OCT Attachment Status Codes Single Stage Furnace with 2-Stage Air Conditioner Airflow Selections ECM Furnaces TWO Stage NON-COMMUNICATING 127A/226AOperating Ambient Airflow Selection for FV4C Fan Coils non-communicatingDefrost Speedup System Function and Sequence of OperationCompressor Operation Check Charge Indoor Thermostat Control Options TWO Stage Communicating 167A/266AAirflow Selections for ECM Furnaces non communicating Evolution Controlled Low Ambient Cooling Defrost HoldMajor Components For Evolution Control only, Green communications Comm Light Communication and Status Function LightsOutdoor Fan Motor Operation 2230V Brown-Out Protection Defeated No 230V at Compressor Contactor Thermistor CurveOutdoor Coil Thermistor OCT Attachment 167A / 266A Troubleshooting Status CodesCare and Maintenance Final Check-Out Puronr R-410A Refrigerant Quick Reference GuideAIR Conditioner Troubleshooting Chart Heat Pump Troubleshooting Heating Cycle Heat Pump Troubleshooting Cooling Cycle TWO-STAGE 286A/288A 180A/187A Index of TablesDescription Table # TWO-STAGE 286B/288B 180B/187BCatalog No. SM01---6
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R-22 specifications

The Bryant R-22 stands out in the landscape of residential heating and cooling systems with its combination of efficiency, durability, and modern technology. Designed primarily for homeowners seeking comfortable climate control solutions, the R-22 model delivers consistent performance throughout varying seasonal extremes.

One of the main features of the Bryant R-22 is its high energy efficiency. Rated with a SEER (Seasonal Energy Efficiency Ratio) that meets or exceeds industry standards, this air conditioning unit is designed to reduce energy consumption while providing optimal cooling. This not only helps in lowering monthly utility bills but also promotes environmentally responsible usage.

Another notable characteristic is the unit's durability. Constructed with a robust cabinet and high-quality components, the R-22 is built to withstand the rigors of daily use, with protective features that enhance its longevity. The cabinet comes with a powder-coated finish that resists corrosion and harsh weather conditions, ensuring that the unit stays functional and aesthetically pleasing for years.

The Bryant R-22 also incorporates advanced technology to improve user experience. One such innovation is the SmartSet technology, which allows homeowners to program their unit to optimize comfort levels according to their specific needs. This programmable capability enhances energy savings and ensures that the home remains at the desired temperature when residents are present.

Moreover, the unit features a Quiet Operating System that significantly reduces noise levels, making it suitable for residential areas where noise might be a concern. The design minimizes vibrations and optimizes airflow, creating a comfortable environment without disruptive sounds.

For added convenience, the Bryant R-22 is compatible with various thermostat options, including Wi-Fi-enabled models. This allows users to control their home's climate from anywhere using a smartphone app, facilitating effortless adjustments and monitoring of energy usage.

Finally, the Bryant R-22 is backed by a solid warranty, providing peace of mind for homeowners. This commitment to quality and customer satisfaction is a testament to Bryant’s dedication to producing reliable and efficient HVAC solutions. Overall, the Bryant R-22 is an exemplary choice for those looking to enhance their home comfort with the latest in HVAC technology.
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