ELECTRONIC CONTROL SEQUENCE OF OPERATION

Mode Control

The mode control pad(s) allow the selection of the operating modes of the unit.

There is a two second delay before the mode activates its appropriate relay.

OPERATING SEQUENCE / CHARACTERISTICS AND FEATURES

Compressor Operation

The run state of the compressor is determined by the difference between the indoor ambient temperature and the set temperature. See specific mode of operation for details.

Compressor Time Delay: 180 seconds

This feature is initiated every time the compressor is de- energized, either due to:

(1)satisfying the temperature set point

(2)changing mode to fan only

(3)a power interruption or

(4)turning the unit off

The compressor is also time delayed for 3 minutes when the control is first plugged in or power is restored after failure. When the compressor cycles off as a result of satisfying the “load”, the time delay is typically timed out during the off cycle. Compressor time delay is bypassed by “Test Mode”.

Return Air Temperature Sensor

The control range is 60°F to 90°F +/- 2.0°F.

Frost Protection Sensor

Temperature settings:

Disable the compressor when sensing 30 +/- 3°F for 2 min. continuously.

Enable compressor @ 55 +/- 5°F.

The fan should not be affected by the Frost Protection. It should continue to function normally if freeze protection is called for.

COOL Mode for XQ Models

When in the COOL mode, the control will turn on the compressor when the indoor temperature is 1.5°F above the set point and turn off the compressor when the ambient gets below the set point by 1.5°F. The fan will run continuously.

MONEY SAVER Mode

When in MONEY SAVER mode, the system will be turned on when the indoor temperature gets above the set point by 0.75°F and turns off when the indoor temperature gets below the set point by 0.75°F. The fan will turn on 5 seconds before the compressor and turn off 5 seconds after the compressor stops. If the compressor is delayed the fan will continue to run while the compressor restarts. If the thermostat remains satisfied for more than approximately 9 minutes, the fan will turn on for a period of 90 seconds for air sampling. Operation in MONEY SAVER mode will light both the MONEY SAVER and COOL indicators.

FAN ONLY Mode

When in the FAN ONLY mode, the compressor will not operate. The fan will run continuously at the user-selected speed (see “Fan Speed Set” below). Smart Fan is not available in FAN ONLY Mode.

Fan Speed Set

XQ fan speed is changed by pressing FAN SPEED button and scrolling through F1, F2, F3 and SF (Smart Fan) in the digital display.

There will be a 2 second delay before the fan speed changes to prevent unnecessary switching of the relays during fan speed selection.

SMART FAN

On the XQ model, smart fan is activated by pressing the FAN SPEED button and scrolling through speeds until “SF” appears in the digital display. Using the remote control, Smart Fan is selected by the fourth push of Fan Speed button.

Smart fan changes fan speeds based on the temperature differential between the ambient and set temperatures.

Checking Room Temperature

Check the room temperature at the electronic control pad by pressing the “FAN SPEED” button and the “TEMP” button at the same time on XQ models.

The indoor temperature will display for 10 seconds. Indoor temperature can be viewed in all modes, including the TEST mode. The display can be changed back to SET temperature by pressing any key, except the ON/OFF button, or after 10 seconds has elapsed.

Keep Alive

The electronic control has a memory to retain all functions and status as set up by the user in the event of a power failure. Once power is restored to the unit there is a two second delay before the fan comes on and approximately three minutes delay before the compressor is activated, providing that the mode was set for cooling and the set point temperature has not been met in the room.

reboot/reset the control board

With unit on, press “MODE” and “TEMP/HOUR ” buttons simultaneously for 10 seconds. If the panel will reboot, you will hear the fan come on and the temperature window will read 60 degrees. If this happens, turn the unit off for about 10 seconds and then turn it back on to finish the reboot cycle. If the panel does not reboot, you possibly need to replace it.

11

Page 11 Page 13
Page 12
Image 12
Friedrich R-410A Electronic Control Sequence of Operation, Operating Sequence / Characteristics and Features, Smart FAN
Page 11 Page 13

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