Hitachi RAC-18SX8 Service Manual page 89

Dehumidifying operation
Dehumidification temperature
setting
(remote control temperature
setting + SHIDD)
30' 15'
(Limit time elapsed) (Forcible operation) (Limit time elapsed) (Limit time elapsed)
(Forcible operation) (Forcible operation)
Fan speed set to AUTO Fan speed set to AUTO Fan speed set to AUTO
START/STOP switch
Operation lamp
Temperature judgment
Weak heating Cooling dry
Operation status Weak heating Heating dry Heating dry
Room temperature category
Category 1 Category 2 Category 1 Category 2 Category 3
HI
MED
Indoor unit
LOW
SILENT
1' 2' 1'
15" 30" 15" 30"
Outdoor unit
1" 1"
Latch-type reversing valve
1"
1' 1'
Room two-way valve
Open
90"
90"
90" 90" 90"
ＷＡ Ｒ Ｌ ＯＷ １
Ｓ Ｔ Ａ Ｒ Ｃ Ｐ Ｌ
ＷＡＲＬＯＷ１ ・ ２ ＷＡＲＬＯＷ１ ・ ２
WAMDRY1・2・3
ＷＡＭ Ｄ Ｒ Ｙ １ ・ ２ ・ ３
ＷＡ Ｒ Ｌ ＯＷ２ ＷＡ Ｒ Ｌ ＯＷ２
COLDR
DMIN
Notes:
(1) The product determines the room temperature category and external temperature category as shown in Tables 1, 2, and 3 according to the room temperature and
external temperature, and performs control as shown in Tables 4 and 5.
(2) For the outdoor unit, its operation pattern is controlled as shown in Table 6 according to the room temperature category and external temperature category.
(3) If the operation status shown in Table 5 makes a state transition depending on the changes in room temperature or external temperature, the product will perform cycle
balancing with a compressor stop time as shown in Table 7.
(4) The operation time with the operation status in "weak heating" is up to 30 minutes. If the room temperature does not rise to room temperature category 2 after that time
limit has elapsed, the product will forcibly perform a "heating dry" operation for 15 minutes. (If the temperature does not rise to the room temperature setting, the product
will repeat "weak heating" and "heating dry.")
(5) When the external temperature ≧ 27℃, the operation in the heating region is inhibited. (The heating region will become a heating dry region.)
(6) When the temperature judgment is low humidity in room temperature category 2, the product will be stopped. (The compressor stop time at that time is 3 minutes or
more.) Provided that the product will not stop in clothes drying mode.)
(7) The temperature setting for dehumidifying operation must be set to the room temperature measured at the time of operation startup. Provided that the lower limit is 13℃
and the upper limit is 26 ℃. The fan speed is MED.
(8) The temperature setting for drying clothes must be the room temperature at the time of operation startup. Provided that the lower limit is 20℃ and the upper limit is 26℃.
The fan speed is HI.
(9) Dew control is operated in room temperature category 2 (WAMDRY1) only. The product will not stop even at low temperature. Weak heating will be activated at a room
temperature of 10℃ or less. The fan speed is MED.
(10) The humidity setting is about 50% in standard mode, about 40% in powerful mode, and about 60% in sleep mode.
(11) In room temperature category 2 or 3, the difference from the room temperature setting and humidity will cause the outdoor unit and compressor speed to be corrected
between C and J as shown in Table 6. Provided that, if the external temperature ≧ 29℃, the lower limit will be H.
(12) If the product is stopped in "heating dry" or "cooling dry," the outdoor unit will run for 30 seconds with the outdoor unit pattern J.
Room Temperature
３ ０ ' １ ５ '
(Limit time elapsed) (Forcible operation)
High humidity
Weak cooling Heating dry Weak heating Heating dry
Category 4 Category 2 Category 1 Category 2
1' 3' 1'
30"
15"
1" 1"
1'
100'
COLMAX-COLMIN
1"
90"
STPSPTM1 ・ 2 ・ 3
90"
WARLOW1
WAMDRY1・2・3
WARLOW2
ＷＡＭ Ｄ Ｒ Ｙ １ ・ ２ ・ ３
ＣＯ Ｌ Ｄ Ｒ Ｙ
Table 1 Room temperature category
(at the time of operation startup)
Room temperature Room
(relative value from the temperature
temperature setting)
category
＋a℃
＋b℃
DRLWT ℃
−
High humidity
Low
humidity
Heating dry
Table 4 Control by room temperature category
Room
temperature Compressor speed
category
COLMAX
Category 4
COLMIN
30" 30"
Category 3
COLDRY
WAMDRY3
Category 2
WAMDRY2
WAMDRY1
Category 1
WARLOW1
90"
WAMDRY1・2・3
Table 6 Control pattern for the outdoor unit
3' minimum
Pattern Control sequence
Ａ
SS1
Ｂ
SS3
Ｃ
Lo
Ｄ
SS1
Ｅ
SS2
Ｆ
SS3
Ｇ
SS4
Ｈ
SS5
Ｉ
SS6
Ｊ
SS7
(T1=GFSTM1,T2=GFSTM2)
Table 2 Room temperature category
(during operation)
Room temperature category
Room temperature
When the room When the room
(relative value from the
When the room temperature declines temperature declines
temperature setting) temperature rises (when shifted from (when shifted from
category 3) category 4)
Category 4
Category 4
＋a℃
Category 3
Category 3
＋b℃
＋1.0℃
Temperature setting
Category 2
Category 2
−1.0 ℃
DRLWLT ℃
−
Category 1
Category 1
Table 5 Outdoor unit control (initial values) according to the room
temperature and external temperature
External temperature
Room two- Latch-type
Room
way valve four-way valve temperature category
Fully Cooling
open position Category 4
Fully closed Cooling position
Fully
Cooling
Category 3
position
closed
Fully open Heating position
Category 2
Category 1
The outdoor unit patterns I and J are used for correction.
Table 7 Stop times in a state transition of the
operation status
Compressor
State transition
stop time
4'
Weak cooling ⇒ heating dry
T1
Heating dry ⇔ cooling dry
4'
Cooling dry ⇒ weak cooling
T2
Heating dry ⇒ weak cooling
Heating dry ⇒ weak heating
Weak heating ⇒ heating dry
Table 8 Relative values from the temperature setting
State External temperature External temperature
transition
＜32℃ ≧32℃
ａ
DRCLCHK1
ｂ
DRCDCHK1
Note:
1. For the constants expressed in uppercase alphabet letters in the figure,
see the data in PWRITE-ZU.
– 111 –
Table 3 External temperature category
External temperature category
External
temperature When the external When the external
temperature rises temperature declines
Category 4
29℃
27℃
Category 3
20℃
18℃
Category 2
10℃
8℃
Category 1
category Category 1 Category 2 Category 3 Category 4
Weak Weak Weak Weak
Operation status
cooling cooling cooling cooling
Outdoor unit
C C C C
control pattern
Cooling Cooling Cooling Cooling
Operation status
dry dry dry dry
Outdoor unit
B B G H
control pattern
Cooling
Operation status Heating dry Heating dry Heating dry
dry
Outdoor unit
A A F H
control pattern
Weak Weak Weak
Operation status Heating dry
heating heating heating
Outdoor unit
C C C C
control pattern
None
None
3 minutes
3 minutes
3 minutes
1 minute
DRCLCHK2
DRCDCHK2