Protective Functions - Sanyo SAP-KRV94EHDX Technical & Service Manual

9-2. 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.
Approx.
53
Approx.
47
a
Area: Automatic capacity control
a.
When Point A has been exceeded, the operation frequency is
b.
reduced by a certain proportion.
Area: Frequency increase is prohibited.
c.
At Point B and below, overload prevention is ended and
d.
control is the same as in the
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.
Freeze-prevention operation is engaged when the
1.
temperature of the indoor heat exchanger is below 6 C.
Restart after freeze-prevention operation occurs when the
2.
temperature of the indoor heat exchanger reaches 8 C or
above.
8
A
6
2
*
a
Area: Automatic capacity control
a.
When the temperature drops below Point A, the operation
b.
frequency is reduced by a certain proportion.
Area: Frequency increase is prohibited.
c.
When the temperature reaches Point C or above, freezing
d.
prevention is ended and control is the same as in the
*
When the temperature drops to below 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.
NOTE
The Freeze Prevention Control during the Low Ambient
Cooling Mode (outside air temperature:15 C or lower) is as
follows.
The compressor stops when the temperature of indoor heat
exchanger becomes less than 2 C.
The compressor restarts when the temperature of indoor heat
exchanger becomes 8 C or higher.
Indoor heat exchanger
A
A. Control start
B. Control end
B
b c d
area.
a
C
B
b c
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
LL
Stopped
NOTE
The fan speed is forcibly changed to "LL" beginning 30 seconds
after the thermostat turns OFF.
Normal 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 20 C or
higher, or until the room temperature reaches 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 ( C)
Approx.
101
Approx.
d
Area: Automatic capacity control.
a.
When the temperature rises above Point A, the operation
b.
frequency is reduced at a specified rate.
area.
a
Area: Further frequency increase is prohibited.
c.
When the temperature falls below Point B, prevention of a rise
d.
in frequency is released and the air conditioner operates as in
area.
a
*
The compressor will stop if the temperature of the compressor
discharge exceeds 120 C due to shortage of gas or other
reason.
41
Set fan speed
Normal operation
25 30
Indoor heat exchanger
temperature ( C)
A
94
a b
At start of operation
Approx. 40
B
c d