8-2. Protective Functions
Overload prevention during heating
During HEAT operation, the temperature of the indoor heat exchanger is used to control the frequency and lessen the load on the compressor before the protective device is activated.
Indoor heatexchanger | temperature °F(°C) | Approx. |
| A |
| Indoor heat exchanger |
127 |
|
| A. Control start | |||
|
|
| ||||
(53) |
|
|
| B. Control end | ||
|
|
|
| |||
Approx. |
|
|
| B | ||
117 |
|
|
| |||
|
|
|
| |||
(47) |
|
|
|
| ||
| a | b | c | d |
a.Area: Automatic capacity control
b.When Point A has been exceeded, the operation frequency is reduced by a certain proportion.
c.Area: Frequency increase is prohibited.
d.At Point B and below, overload prevention is ended and control is the same as in the a area.
Freeze prevention
During COOL or DRY operation, freezing is detected and operation is stopped when the temperature of the indoor heat exchanger matches the conditions below.
1.
2.Restart after
Indoor heat exchanger | temperature °F(°C) | 46 |
|
|
| C |
(8) |
|
|
|
| ||
43 |
| A | B |
| ||
(6) |
|
|
|
| ||
36 |
|
|
|
| ||
(2) | * |
|
|
| ||
|
|
| a | b | c | d |
a.Area: Automatic capacity control
b.When the temperature drops below Point A, the operation frequency is reduced by a certain proportion.
c.Area: Frequency increase is prohibited.
d.When the temperature reaches Point C or above, freezing prevention is ended and control is the same as in the a area.
*When the temperature drops to below 36°F(2°C) (continuously for 2 minutes or longer), the compressor stops. Once the freeze condition is detected, the air conditioner will work less than the maximum frequency until it is turned off.
Cold-air prevention during heating
During heating, the fan speed is set to "LL" (very low) or stopped. As the temperature of the indoor heat exchanger rises, the fan speed is changed to the set speed.
High |
|
| Set fan speed |
|
|
| |
| At stability of operation |
| |
|
|
| At start of operation |
LL |
|
|
|
Stopped | 77 | 86 | Approx. 104 |
| |||
| (25) | (30) | (40) |
Indoor heat exchanger
temperature °F(°C)
NOTE
•The fan speed is forcibly changed to "LL" beginning 30 seconds after the thermostat turns OFF.
•At stability of operation refers to operation when the room temperature has approached the set temperature.
•When HEAT operation starts, the indoor fan is stopped until the temperature of the indoor heat exchanger reaches 68°F(20°C) or higher, or until the room temperature reaches 59°F(15°C) or higher.
Compressor discharge temperature control
This function controls the operation frequency to prevent the compressor discharge temperature from rising more than a specified temperature.
Compressor discharge temperature °F(°C)
Approx. | A |
|
|
214 |
|
|
|
(101) |
|
|
|
Approx. |
|
| B |
201 |
|
| |
|
|
| |
(94) |
|
|
|
a | b | c | d |
a.Area: Automatic capacity control.
b.When the temperature rises above Point A, the operation frequency is reduced at a specified rate.
c.Area: Further frequency increase is prohibited.
d.When the temperature falls below Point B, prevention of a rise in frequency is released and the air conditioner operates as in a area.
*The compressor will stop if the temperature of the compressor discharge exceeds 248°F(120°C) due to shortage of gas or other reason.
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