Hitachi RAC-18SX8 Service Manual page 97

Temperature setting
The temperature setting is determined based on the room temperature that was effective at operation startup.
"Room temperature setting" = current room temperature +
lower limit 26℃)
Region judgment
The regions comprise "low-temperature stop region," "weak heating region, " and "dehumidification region."
(1) At operation startup
(1.1) Low-temperature stop region
・When the room temperature ＜
1℃
(1.2) Dehumidification region
・When the external temperature ＞
20℃
(1.3) Weak heating region
・When the external temperature ≦ 20℃
(2) During operation
(2.1) "Weak heating region" "dehumidification region" ⇒ "low-temperature stop region"
・When the room temperature ＜ 1℃
(2.2) Return from the "low-temperature stop region"
・When the room temperature ≧ 1℃
(In this case, region judgment is performed at the time of operation startup.)
(2.3) "Weak heating region" ⇒ "dehumidification region" (either of the following)
(a) When the maximum operation time "60 minutes" has elapsed
(b) The minimum operation time has elapsed and when the humidity ＞ 45% and the room temperature
≧ temperature setting
(c) When the minimum operation time has elapsed and when the external temperature
※The minimum operation time is 15 minutes if shifted from the dehumidification region, and 30 minutes
in all other cases.
(2.4) "Dehumidification region" ⇒ "weak heating region" (either of the following)
(a) Minimum operation time "30 minutes" has elapsed and when the humidity
(b) Minimum operation time "30 minutes" has elapsed and when the room temperature
(3) OFF timer reserved
Some 30 minutes before the OFF timer setting, forcible operation will start. Provided that it will stop if the room
temperature ＜ 1℃
(3.1) Dehumidification will be performed from "30 minutes until 7 minutes before" the OFF timer setting.
(3.2) Weak heating operation will be performed from "7 minutes before until the time is up" as set in the OFF timer.
Balancing time
The same as other dehumidification modes.
(1) "Weak heating region, dehumidification region" ⇒ "low-temperature region" --- 3 minutes
(2) "Weak heating region" ⇒ "dehumidification region" --- 1 minute
(3) "Dehumidification region" ⇒ "weak heating region" -- 3 minutes
4℃ (provided that the upper limit is 29℃ and the
≧ 29℃
≦
45%
≦ 15℃
Laundry
Operation details
(1) Weak heating region
(1.1) Room temperature control
・When the room temperature
(forcibly balanced for 3 minutes).
・When the room temperature
(forcibly operated for 3 minutes).
(1.2) Humidity control
・Nothing in particular.
(1.3) Outputs
(a) Indoor unit
・As per the fan speed settings. If AUTO, "MED." (When the thermometer is off, too, the product will run at
a specified fan speed.)
(b) Operation display
・The operation lamp is lit up.
(c) Outdoor unit
・Fixed at the Lo tap.
(d) Compressor speed (the temperature hysteresis is 0.66℃)
・Room temperature ＜ temperature setting
・Room temperature ＜ temperature setting ---- 1,800
・Room temperature ≧ temperature setting --- DMIN
(e) Other
・The other outputs are the same as the other dehumidification modes.
(2) Dehumidification region
(2.1) Room temperature control
・Nothing in particular.
(2.2) Humidity control
・Nothing in particular. The product will not stop at low humidity.
(2.3) Outputs
(a) Indoor unit
・It conforms to the fan speed setting. If AUTO, "super-HI."
(While the thermometer is off, too, the product will run at the specified fan speed.)
(b) Operation display
・The operation lamp is lit.
(c) Outdoor unit
・This is selected according to the external temperature.
(The same as heating dry in other dehumidification modes. Provided that no correction will be performed.)
(d) Compressor speed
・Normally 1,600.
・2,000 during powerful operation.
(e) Other
・The other outputs are the same as the other dehumidification modes.
≧ temperature setting + 1.33℃, the thermometer will become turned off
≦
temperature setting + 0.66℃, the thermometer will become turned on
-2℃ --- 2,800
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