Friedrich R-410A service manual Connecting a Remote Wall Thermostat

Page 33

Low Voltage Interface Connector

WARNING

ELECTRIC SHOCK HAZARD

Disconnect power to the unit before servicing. Failure to follow this warning could result in serious injury or death.

All Kuhl and Kuhl + units have a low voltage interface connector through which a Remote Wall Thermostat, Desk Control and Auxiliary Fan’s Relay can be connected. The interface connector is located on the left side behind the decorative front cover.

Interface Connector Location

Figure 1

Table 1

 

Interface Connector Definitions

 

 

 

Front Panel. Wire jumper between FP and

FP

F2 enables front panel operation. Jumper off

 

enables remote wall t-stat operation.

F2

Used with F1 to provide 24 VAC to external

fan relay. (See above for use with FP)

 

 

 

F1

Used with F2 to provide 24 VAC to

external fan relay.

 

 

 

D2

Used with D1 for desk control on or off

operation.

 

 

D1

Used with D2 for desk control on or off

operation.

 

 

C

Common Ground Terminal

 

 

GH

Call for high fan

GL

Call for low fan

B

Call for heat pump reversing valve

 

 

Y

Call for compressor

 

 

W

Call for heating

R

24V Power from Electronic Control to Wall

 

 

Adding a Remote Wall Thermostat

An external thermostat may be added to the air conditioner to provide remote temperature sensing and control.

Thermostat Selection

Friedrich recommends the use of either the Friedrich RT4 or RT5. These thermostats are single stage heat/cool, manual changeover. The RT4 is a digital display thermostat with single speed fan control. The RT5 features a digital display, two fan speed selection, filter check light, temperature limiting, status indicator light, room temperature offset, backlight and battery backup. Other thermostats may be used as long as they are single stage heat/cool and are configured correctly for the unit.

Thermostat terminals requirements:

For cooling only units: C, R, G, Y.

For cooling with electric heat units: C, R, G, Y, W.

For heat pump units: C, R, G, Y, W, B.

For two fan speeds, thermostat must have 2 fan speed selection.

During Heat Pump Mode:

The B terminal must be continuously energized. The W terminal must have 24 VAC output to call for heat. The control board decides on whether to turn on the Heat Pump Heat (compressor) or Electric Heat. The Y terminal should not have 24 VAC output during heat mode.

Connecting a Remote Wall Thermostat

To enable the remote thermostat operation, remove the jumper between terminals FP & F2 on the interface connector. Connect the thermostat using Figure 1 and Table 1 as a guide.

Procedure

1)Unplug the unit.

2)Unscrew and remove the decorative front cover. (Page 30)

3)Locate the Interface Connector (24 VAC terminal strip (See figure 1 at left) and remove the jumper wire at FP and F2.

4)Make the wire connections according to the configuration needed for your unit (see above or page 68 for wiring diagrams).

5)Once each wire is matched and connected, the unit is now ready to be controlled by the thermostat.

6)Reattach the decorative front cover (see page 30).

Note: Under T-Stat operation the front panel is disabled except the Maintenance functions (see page 29 for details).

32

Page 32 Page 34
Image 33
Page 32 Page 34
Contents Cool with Electric Heat Cool OnlyHeat Pump with Electric Heat Heat Pump Volt YS10M10Table Of Contents Your safety and the safety of others are very important Important Safety InformationRefrigeration System Repair Hazards Property Damage Hazards Model and Serial Number Location IntroductionUnit Identification Performance Data SpecificationsInstallation Information / Sleeve Dimensions Electrical Data Electric Shock HazardFire Hazard Make sure the wiring is adequate for your unit Control Panel Operation Special Functions System Exit Back FAN Mode Speed Display Schedule Enter Key Sequence Action Digital Control Panels Access Codes SummaryRemote Control Operation Remote Control Operation Introduction Electronic Control System MaintenanceElectronic Control System Maintenance Operation Following functions Can be Tested Test mode BypassesFactory USE only To Clear Error Codes’ HistoryFront Panel Unit OperationSystem Set Point Mapping Figure COOL-HEAT SET PointsCompressor Operation Electronic Control Sequence of OperationHeat Control Heat Pump Only Heating Mode Control OperationCondition Heat Pump With Electric Heat OperationElectric Heat Operation in Cool with Electric Heat Units Compressor Lock Out Time Fan Mapping Unit Operation with a WALL-STAT During Heat ModeRemoving the Front Cover Swing Out Replacing the Indoor Coil ThermistorConnecting a Remote Wall Thermostat Remote Wall Thermostat Location Capacitors Components TestingCapacitor Check with Capacitor Analyzer Capacitor ConnectionsHeating Element Testing the Heating Element Electric Shock HazardHeating Element Heat Pump Models Drain PAN ValveRefrigeration Sequence of Operation Refrigeration system under high pressure 410A Sealed System Repair ConsiderationsEquipment Required 410A Sealed Refrigeration System RepairsEquipment Must be Capable Risk of Electric ShockMethod Of Charging / Repairs Burn HazardFreeze Hazard Overcharged Refrigerant Systems Undercharged Refrigerant SystemsRestricted Refrigerant System Metering Device Hermetic Components CheckCheck Valve Capillary Tube SystemsReversing Valve DESCRIPTION/OPERATION Testing the Reversing Valve Solenoid Coil Reversing Valve in Heating ModeChecking the Reversing Valve Procedure For Changing Reversing Valve Touch Test in Heating/Cooling CycleExplosion Hazard Compressor Checks Single Phase Resistance Test Ground TestChecking Compressor Efficiency Compressor Replacement Recommended procedure for compressor replacementHigh Temperatures High Pressure Hazard Routine Maintenance Sleeve / Drain Decorative Front CoverClearances Standard Filter Cleaning Installation Instructions Battery type Lithium, 3 Volts, #CR2450 Control Panel Battery Change ProcedureService and Assistance Room AIR Conditioner Unit Performance Test Data Sheet Icon Error Codes and Alarm StatusProblem Possible Cause Possible Solution Troubleshooting TipsTroubleshooting Tips Problem Possible Cause Possible Solution Cooling only Room AIR Conditioners Troubleshooting TipsReplace fuse, reset breaker. If repeats, check Possible Cause Possible Solution Problem Possible Cause Possible Solution Bad outdoor coil thermistor Replace thermistor Heat / Cool only Room AIR Conditioners Troubleshooting TipsHeat Pump Room AIR Conditioners Trouble Shooting Tips Troubleshooting Chart Heat PumpProblem Possible Cause Action System Cools When Heating is Desired Electrical Troubleshooting Chart Heat PumpHeat Pump YESMalfunction of Valve Normal Function of ValveDischarge Electronic Control Board Components IdentificationCool W/O Electric Heat Remote Wall Thermostat Wiring DiagramsKuhl Electronic Control Cool only Models SchematicSL28M30A, SL36M30A ES12M33A, ES15M33A EM18M34A, EM24M34A KUHL+ Electronic Control Cool with Electric Heat ModelsEL36M35A KUHL+ Electronic Control Cool with Electric Heat ModelYS10M10A KUHL+ Electronic Control Heat Pump only ModelHeat YL24M35A KUHL+ Electronic Control Heat Pump with Electric Heat ModelThis Table Applies to All Thermistors THERMISTORS’ Resistance ValuesReplacement Remote Control Configuration Instructions Checking the Remote Control’s OPT # Code Replacement Instructions Aham PUB. NO. RAC-1 Cooling Load Estimate Form Heat Gain from Quantity FactorsDAY Heat Load Form Following is an example using the heat load formHeating Load Form Friedrich Room Unit Heat Pumps Windows & Doors Area, sq. ftInfiltration Windows & Doors AVG Room AIR Conditioners Limited Warranty Technical Support Contact Information Friedrich AIR Conditioning CO
Related manuals
Manual 32 pages 34.87 Kb Manual 47 pages 33.75 Kb Manual 16 pages 9.01 Kb Manual 32 pages 56.71 Kb

R-410A specifications

Friedrich R-410A is an advanced refrigerant widely used in HVAC (Heating, Ventilation, and Air Conditioning) systems, known for its high efficiency and environmental friendliness. As a hydrofluorocarbon (HFC) blend, R-410A has become the preferred alternative to R-22, which is being phased out due to its ozone-depleting potential. One of the main features of R-410A is its high latent heat of vaporization, which allows for efficient heat transfer and improved cooling performance in air conditioning units.

Technologically, R-410A operates at higher pressures than older refrigerants, meaning systems designed for R-410A need to be built with more robust components to safely handle these pressures. This results in a more compact system design that offers enhanced performance and reliability. The dual-component nature of R-410A—composed of difluoromethane (R-32) and pentafluoroethane (R-125)—provides an optimal balance of thermodynamic properties, leading to superior energy efficiency, especially in variable speed applications.

In terms of characteristics, R-410A has a higher cooling capacity, which enables HVAC systems to effectively cool larger spaces or run more efficiently when cooling smaller areas. The refrigerant is non-toxic and non-flammable, which enhances safety during its use. In addition, R-410A has a lower global warming potential relative to other refrigerants, making it a more environmentally responsible choice for modern cooling systems.

Moreover, R-410A systems typically require less refrigerant charge due to their efficiency, contributing to reduced greenhouse gas emissions. The adoption of R-410A aligns with regulatory trends aimed at minimizing the environmental impact of refrigerants in cooling applications.

Overall, the Friedrich R-410A refrigerant embodies a combination of technology and environmental stewardship, making it a cornerstone of contemporary HVAC design. Its ability to provide effective and energy-efficient cooling solutions while being compliant with modern environmental regulations positions R-410A as the refrigerant of choice for engineers and installers focused on sustainability and performance in air conditioning systems.
Top Page Image Contents