Hitachi RAS-3HVRNS - Page 156

Outdoor fan control during heating operation
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29
26
23
20
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Fan step:
30% area
Outdoor temperature (ºC)
Operation
30% area (1*)
Yes
No
Pressure
switch for control:
OFF ON
Is fan operated
for more than
3 min.?
No
No
Yes
≥ 100%
TrL ≥ TrL1+2
Is fan operated
for more than
3 min.?
A
Yes
Yes
No
No
Temp. on the top
of comp. ≥ 100ºC
and EVO ≥ 400 pulse
Pressure switch
for control: ON
Outdoor liquid
pipe temp. (Te)
same condition
Pressure
switch for control:
OFF ON
VL decreased and
pressure switch for
control: ON
Is fan operated
more than 3 min.?
Is fan operated
more than 3 min.?
110%
1 step up
1 step down
Yes
TrL≥TrL1+2
ratio 100%
Temp. on the top
of comp. ≥ 95ºC
No
No
No
Yes
> 7 ºC
≤ 1 ºC
Yes
Yes
Yes
No
2 step down
No
Yes
No
Yes
No
Yes
A
Yes
*1
Inlet air temp. of
indoor unit (ºC)
Outdoor temperature (ºC)
No
No
ratio 110%
No
Yes
Yes
Outdoor liquid
pipe temp. (Te)
≤ 7ºC
> 1 ºC
TrL: Indoor unit liquid pipe temp.
TrL1: Indoor unit liquid pipe
temp. on switching PSC for
control ON
5 Control System
148
SMGB0060 rev. 1- 12/2010