2-4 Control Functions

Electronic control valve control

Opening of the electronic control valve is controlled so that the appropriate operating conditions are maintained, based on the signal from each sensor (discharge temperature [TD], intake temperature [TS], outdoor heat exchanger temperature [C1], and indoor heat exchanger temperature [E1, E2]).

Discharge temperature release control

(1)This control lowers the operating frequency of the compressor when electronic control valve control is unable to maintain the appropriate operating conditions because the discharge temperature fails to decline or because there is a sudden increase in the discharge temperature.

(2)If the discharge temperature exceeds 232°F, the compressor is stopped and then restarted. (Error count = 1)

(3)The error count is cleared when operation has continued for 10 minutes after the compressor was restarted.

(4)If (2) repeats 4 times without the error count being cleared (error count = 4), alarm "P03" occurs.

Current release control

The compressor operating frequency is controlled so

2 that the current that is input to the inverter compressor does not exceed the designated value (control value).

Outdoor unit fan control

1. Cooling fan control

(1)The outdoor unit fan minimum speed and maximum speed are determined according to the outdoor air temperature and the operating frequency. The speed is controlled in stages between the minimum speed and maximum speed, based on the outdoor heat exchanger temperature (C2) at that time.

(2)For 60 seconds after start, the outdoor unit fan operates at maximum speed, as determined by the outdoor air temperature and operating frequency at that time. Subsequently, the fan operates at low speed until the outdoor heat exchanger temperature (C2) rises.

(3)If the discharge temperature (TD) sensor is abnormal or has become disconnected, the fan will not operate and a protective device is activated.

2. Heating fan control

(1)The outdoor unit fan minimum speed and maximum speed are determined according to the outdoor air temperature and operating frequency. The speed is controlled in stages between the minimum speed and maximum speed, based on the outdoor heat exchanger temperature (C1) at that time.

2.Processes and functions

(2)If the outdoor heat exchanger temperature (C1) is 75°F or higher continuously for 5 minutes, fan operation may stop (same conditions as when the thermostat is OFF). In this case, the fan will restart after 3 minutes.

(3)This control is not performed during the 3 minutes after start, for 1 minute after defrost ends, and while defrost is in progress.

Coil heating control

(1)This control applies current to the coil of the stopped compressor to heat the compressor in place of the crank case heater.

(2)When the discharge temperature (TD) is less than 77°F, the current application judgment is made based on the outdoor air temperature (TO).

Current application starts when the outdoor air temperature drops to 59°F or below.

Current application stops when the outdoor air temperature rises above 64°F.

Control for prevention of short intermittent operation

In order to protect the compressor, this control does not allow the compressor to be stopped for 10 minutes after operation starts, even if the thermostat OFF signal is received from the indoor unit.

Control for prevention of high cooling loads

This control reduces abnormal high-pressure increases during cooling operation.

(1)If MAX (C1, C2) (C1 & C2: outdoor heat exchanger temperature) is less than 124°F, the compressor performs normal operation.

(2)If MAX (C1, C2) is 124°F or higher and less than 142°F, the revolution of the compressor is controlled to prevent the high pressure being increased.

(3)If MAX (C1, C2) is 142°F or higher, the compressor stops once. The compressor restarts three times, and if the temperature dose not decrease to less than 142°F, the alert "P20" is displayed.

142

124

2-6

Page 136
Image 136
Panasonic R410A service manual Discharge temperature release control, Current release control, Outdoor unit fan control

R410A specifications

Panasonic R410A is a refrigerant that has gained significant popularity in the air conditioning and refrigeration industry due to its favorable environmental properties and performance characteristics. Specifically designed to replace the harmful R22 refrigerant, which is being phased out due to its ozone-depleting potential, R410A offers a more eco-friendly alternative without compromising on efficiency or power.

One of the main features of R410A is its high energy efficiency. It operates at a higher pressure than R22, resulting in better heat transfer capabilities. This increased efficiency translates to lower energy consumption, making units using R410A more cost-effective in the long run. Additionally, R410A is known for its ability to provide excellent cooling performance even in high-temperature environments, making it suitable for a variety of applications, from residential air conditioning systems to commercial refrigeration units.

In terms of composition, R410A is a blend of two hydrofluorocarbons (HFCs), namely R32 and R125. This combination not only minimizes ozone depletion potential (ODP) but also reduces global warming potential (GWP) compared to older refrigerants. Panasonic has emphasized the importance of innovative technologies in its products, and R410A aligns perfectly with the company's commitment to developing sustainable solutions.

Panasonic also integrates advanced technologies to optimize the performance of R410A systems. For example, variable speed compressors, known as inverter technology, enhance system efficiency by adjusting the compressor's speed according to the cooling demand. This ensures that energy is only consumed when needed, further reducing operational costs.

Furthermore, R410A has a wide range of applications, including air conditioning systems, heat pumps, and chillers. Its versatility makes it a popular choice among manufacturers and consumers alike. The refrigerant is also compatible with existing R22 equipment, although specific retrofit procedures must be followed to ensure peak performance and reliability.

In conclusion, Panasonic R410A stands out as an innovative refrigerant choice in the HVAC industry, offering a combination of energy efficiency, environmentally friendly properties, and advanced technologies. As regulatory frameworks continue to tighten on greenhouse gas emissions, R410A and similar refrigerants are expected to play a crucial role in shaping a more sustainable future for air conditioning and refrigeration. Its high performance and lower environmental impact solidify its position as a leading refrigerant in contemporary cooling solutions.