Hitachi RAS-18YH4 Service Manual page 33

Heating set temperature
(remote control set temperature
(+))
Dash period
Fan speed set to "auto"
Start
Start/stop button
Thermo judgment
Max. 3 min.
Defrost signal
Preheating released
Preheating judgment
Ultra-Hi
30sec. 30sec.
Hi
Indoor fan
Med
10sec.
Lo
Ultra-Lo
Operation lamp
1 min.
WMAX2
Max.
(WMAX)
NOTE (10)
Rating
(WSTD)
Wtd
3000
WMIN
0
Outdoor fan
Reversing valve (cooling "on" model)
Notes:
(1) Condition for entering into Hot Dashed mode. When fan set to "Hi" or "Auto mode" and i) Indoor temperature is lower than 18°C, and ii) outdoor temperature is lower than 10°C,
and iii) Temperature difference between indoor temperature and set temperature has a corresponding compressor rpm (calculated value in Table 3) larger than WMAX.
(2) Hot Dashed will release when i) Room temperature has achieved the set temperature + SFTDSW. ii) Thermo off.
(3) During Hot Dashed operation, thermo off temperature is set temperature (with shift value) +3°C. After thermo off, operation continue in Fuzzy control mode.
(4) Compressor minimum "ON" time and "OFF" time is 3 minutes.
(5) During normal heating mode, compressor maximum rpm WMAX will maintain for 120 minutes if indoor temperature is higher than 18°C. No time limit constrain if outdoor temperature is
lower than 4°C.
(6) During Hotkeep or Defrost mode, indoor operation lamp will blink at interval of 0.5 seconds "ON" and 0.5 second "OFF".
(7) When heating mode starts, it will enter into Hotkeep mode if indoor heat exchanger temperature is lower than YNEOF + 0.33°C.
(8) When fan is set to "Lo", compressor rpm will be limited to WBEMAX. When fan is set to "Med", compressor rpm will be limited to WJKMAX.
(9) In "Ultra-Lo" fan mode, if indoor temperature is lower than 18°C, indoor fan will stop. If indoor temperature is higher than 18°C + 0.33°C, fan will continue in "Ultra-Lo" mode.
During Hotkeep or Defrost mode, fan will continue in "Ultra-Lo" mode.
(10) During Hot Dashed, when room temperature reaches set temperature + SFTDSW compressor rpm is actual rpm x DWNRATEW.
Basic Heating Operation
Stop Start Stop
Thermo
OFF
30sec. 30sec. 30sec. 30sec.
10sec. 10sec.
15sec.
Control by Control by Control by
heat exchanger temperature heat exchanger temperature heat exchanger temperature
15sec. 15sec. 15sec.
18˚C
Start
Thermo OFF
Preheat released
30sec. 30sec. 30sec. 30sec.
10sec.
15sec.
Control by Control by
10sec. heat exchanger temperature heat exchanger temperature
3min.
15sec.
Table 3 Compressor rpm
compressor rpm
Notes:
1. See the data in Table 1-Table 2 on
Stop
Thermo
OFF
15sec.
15sec.
Temperature
Calculated
difference
(with shift value)
1900 min –1 1.66°C
2400 min –1 2.00°C
–1
2900 min 2.33°C
–1
3400 min 2.66°C
3900 min –1 3.00°C
4400 min –1 3.33°C
4900 min –1 3.66°C
page 47 & 49 for each constant in
capital letters in the diagrams.
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