Protective Functions - Sanyo KMHS0772 Technical & Service Manual

7-2. 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.
127
(53)
Approx.
117
(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.
1. Freeze-prevention operation is engaged when the
temperature of the indoor heat exchanger is below 43°F(6°C).
2. Restart after freeze-prevention operation occurs when the
temperature of the indoor heat exchanger reaches 46°F(8°C)
or above.
46
(8)
A
43
(6)
36
(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 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.
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.
• 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.
d
area.
a
34
Set fan speed
At stability of operation
At start of operation
77 86 Approx. 104
(25) (30)
Indoor heat exchanger
temperature °F(°C)
(40)