TROUBLESHOOTING

Problem

Possible Cause

Possible Solution

 

 

 

 

Power disconnected.

Check power source.

 

 

 

 

Branch circuit fuse blown or circuit

Replace fuse, reset breaker. If repeats, check fuse

 

or breaker size. Check for shorts in unit wiring and

 

breaker tripped.

Unit does not run

components.

 

 

Loose or disconnected wiring at

Check wiring & connections. Connect per wiring

 

switch.

diagram.

 

Inoperative switch (On-Off).

Test for continuity, 3 and 2, 5 and 6. If bad,

 

replace.

 

 

Problem

Possible Cause

Possible Solution

 

 

 

 

Dirty filter.

Clean as recommended in Owner's Manual.

 

Restricted airflow.

Check for dirty or obstructed coil clean as

 

required.

 

 

Evaporator coil

Inoperative thermostat.

Test for shorted thermostat or stuck contacts.

Short of refrigerant.

De-ice coil and check for leak.

freezes up

 

De-ice coil. Check temperature differential

 

 

 

Partially restricted capillary.

across coil. Touch-test coil return bends for same

 

 

temperature. Test for low running current.

 

Inoperative fan motor.

Test fan motor & replace if inoperative.

Problem

Possible Cause

Possible Solution

 

 

 

 

Excessive heat load.

Test cooling performance of unit. Unit undersized.

 

 

 

 

Restriction in line.

Check for partially iced coil. Check temperature

 

split across coil.

Compressor runs

 

 

Check for presence of oil on silver soldered

continually. Does

 

Refrigerant leak.

connections. Check for partially iced coil. Check

not cycle off.

 

split across coil. Check for low running amperage.

 

 

 

Thermostat contacts stuck.

Check operation of thermostat. Replace if contacts

 

remain closed.

 

 

 

 

 

 

Incorrect thermostat setting.

Set to correct setting.

 

 

 

Problem

Possible Cause

Possible Solution

 

Loss of charge in thermostat bulb.

Replace thermostat.

Thermostat

Thermostat contacts open.

Test for continuity at terminals 1 and 2. Replace if

defective.

does not turn on

 

 

 

compressor

Incorrect wiring or loose wires.

Connect per wiring diagram. Tighten loose wires.

 

 

 

 

System switch open.

Test for continuity at switch terminals 2 and 3.

 

 

 

Problem

Possible Cause

Possible Solution

 

Thermostat set at coldest point

Adjust.

 

 

 

Thermostat

 

Disconnect power to the unit. Remove cover of

Thermostat contacts stuck.

thermostat and check if contact is stuck, if so

does not turn off

 

replace thermostat.

compressor

 

 

Switch (On-Off) shorted.

Test switch for open contacts at terminals 2 and 3

 

with switch in “Off” position.

 

 

24

Page 24 Page 26
Page 25
Image 25
Friedrich R-410A service manual Troubleshooting
Page 24 Page 26

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