Daikin LX10F10A, Руководство по обслуживанию

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1.4.4 Defrost Mode
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Hot-Gas Defrost System
A hot gas system is adopted for the heat source;
I.e. the high temperature and high pressure
refrigerant discharged from the compressor is
supplied to the evaporator and drain pan for
defrosting. Since the ice built on the evaporator
is directly and evenly heated up from the inside,
defrosting can be efficiently performed.
●
Display
"DEFROST" is
displayed on the upper
right of the screen.
●
Defrost operation
The pump-down
operation is executed by closing EEV and opening
DMV first.
Then the defrost operation will start by closing
DMV and opening HSV and hot gas is supplied to
the evaporator and drain pan. During defrosting,
the compressor speed is modulated in order to
maintain the optimum hot gas temperature. (High
Pressure Constant Control). The release control
(DMV open, CFM ON) or charge control (ESV ON,
EMV open) is executed for compressor protection.
After termination of defrosting, normal temperature
control operation will start without running EFM for
the first 3 minute by delay timer.
●
In-Range masking
The control temperature temporarily becomes out-
rage during defrosting, but the IN RANGE LED is
kept ON.
This will avoid misunderstanding that there will be a
problem if the IN RANGE LED is turned OFF.
●
Defrost Initiation
Pull-down
Short timer
6Hr
（ 12Hr when RS<-15 ℃）
Automatic
detecting
When supply air temperature does not
drop 0.2
℃ per 1 hr in frozen mode.
"AUTO"
In-Range
Defrost
interval
setting
Defrost interval setting
"3, 6, 9, 12 or 24" Hr
Out-range
timer
Executed by 30 min. timer
after the control temperature
rises out of in-range.
Manual Defrost Executed by MDS key.
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Defrost Initiation Conditions
Timer Count-down Initiation Conditions
Defrost interval (Frozen)
Short timer
Out-range timer
Manual defrost (MDS key)
EOS ≦ 20.0 ℃
Defrost interval (Chilled)
EOS ≦ 20.0 ℃
& EIS<5.0 ℃
If the initiation conditions are not met when timer
counts down, the defrosting will not be initiated.
If "AUTO" is selected, defrosting will be executed
automatically in accordance with the accumulation
of ice on the evaporator coil.
●
Defrost Termination Conditions
Defrosting Time Termination Conditions
＜ 45 minute
EOS ≧ 20 ℃
& (RS ≧ 5 ℃ or RS ≧ 5 ℃ with 10 min.
elapse if RS<-20 ℃ at defrost initiation)
≧ 45 minute
EOS ≧ 30 ℃
& (RS ≧ 15 ℃ or RS ≧ 5 ℃ with 10 min.
elapse if RS<-20 ℃ at defrost initiation)
90 minute
Defrost is forcibly terminated at
90 minutes. (E207
）
Economizer
Reheat coil (option)
Check valve
Condenser
Receiver
Compressor
HPT
HPS
EMV
ESV
LSV
Drier
EEV
LPT
Sight glass
Evaporator
CFM
EFM
RSV HSV
PRV
DMV
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