FILE NO. SVM-09036
-
25
-
7-4-1. Low-Temperature Limit Control
The microcontroller detects the indoor heat exchanger
temperature to prevent the indoor heat exchanger from
freezing.
The compressor and outdoor fan motor are controlled
as shown in Fig. 7-4-1.
Fig. 7-4-1
6
(°C)
2
Compressor Outdoor fan
ON
Less than 2°C continues
for 5 minutes
OFF
Heat exchanger
temperature
7-4. Drescription of Safety and Reliability Prevention Function
7-4-2 High-Temperature Limit Control
The microcontroller detects the indoor heat exchanger
temperature to prevent pressure of a refrigerating cycle
from increasing excessively.
The compressor and outdoor fan motor are controlled
as shown in Fig. 7-4-2.
Fig. 7-4-2
62
(°C)
55
54
Compressor Outdoor fan
OFF
OFF
ON
ON
OFF
ON
Heat exchanger
temp.
7-
4-3
. Defrost Operation *
Heat pump model only
When the indoor unit is in heating operation, if the
refrigerant evaporation temperature detected by the
outdoor heat exchanger sensor is under the specified
temperature, the outdoor unit starts the defrosting
operation. At this time, the 4-way valve relay and the
outdoor fan motor are turned off. The indoor fan motor
is also turned off by the cold draft preventing control of
the indoor microcomputer. Then, [PRE. DEF.] lamp on
the indoor unit comes on.
The defrosting operation stops and the 4-way valve
relay, outdoor fan motor and the indoor fan motor are
turned on automatically when the refrigerant
evaporation increases to the specified temperature, or
when the defrosting time is over 12 minutes.
7-
4
-
3-1
. Defrost starting condition
Teo - Te
≤
-3°C at least 20 sec or ~ 60 min
A-Zone : If -10°C > Teo
≥
- 18°C, defrost will
after operation.
start when.
Teo - Te
≥
2.5°C at teat 20 sec or
~ 30 min after operation.
B-Zone : If Te
≤
-18°C, defrost start instantaneously
(Suddenly) 00 ~ 25 min ofter operation
C-Zone : If -2ºC
≥
Teo
≥
-10°C defrost will start when
Td3 Td4
Finish time record
Start time record
Defrost time rate : (Td/Tt) x 100
Heating time rate : (Tt - Td) x Tt
7-
4-3-2
. Defrost finish condition.
1) If Te
≥
3°C at least 60 sec -->4 way value on.
2) If Te
≥
8°C --> 4 way value on.
Timing
Fig. 7-
4-3
Operation time (4 Loops = Tt)
Td1
Td2
*Heat pump model only
