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AUTO-FRESH DEFROST
During heating operation is stopped, and when auto-fresh condition is established, defrost operation will be performed while
operation is stopped.
Auto-fresh consists of balancing period at start of defrost for [TDF414] seconds Reverse cycle period for MAX 12
minutes.
When all the following conditions are established, auto-fresh is executed:
Defrost request signal is present.
Start conditions for auto-fresh
(1)
15 minutes of auto-fresh inhibit period has elapsed.
All indoor units are stopped.
1
3
2
Compressor delay command is sent from indoor unit when operation is stopped.
Compressor is ON when operation is stopped.
5
4
If any one of following conditions is established, auto-fresh is released:
Unit auto-fresh not applied: FULL CLOSE when balancing for 30 seconds has elapsed at start of defrost.
Unit auto-fresh applied : Synchronized with step-up of rotation speed of compressor, opened by [DFSPPS] pulses and
reaches MAX opening degree [DEFSMX] when rotation speed of compressor reaches [DEFMAX].
Heat exchange temperature returns (heat exchange temperature
≥
DEFOFF)
Release condition of auto-fresh
(2)
Outputs during auto-fresh
[Indoor unit defrost request]: Transmitted only to unit to which auto-fresh is applied (indoor unit stopped last).
[Compressor]: Accelerated by DFSTEP min
-1
/TDFSPT seconds and reaches defrost MAX speed [DEFMAX].
[Electric expansion valve]:
(3)
Failure occurred.
12 minutes of defrost MAX time has elapsed.
1
3
2
Shifted to auto-fresh in defrost mode when operation is stopped.
Note
(4)
All indoor units must be stopped to fulfill condition for auto-fresh.
If signal is delayed, auto-fresh condition will not be established.
Either unit 1 or unit 2 or unit 3 started operation.
Released during start of balancing period : Stopped or started after remaining balancing period has elapsed.
Released during reverse cycle period : Stopped or started after balancing for 3 minutes.
4
Unit 1
Unit 2
Unit 1
Unit 2
Unit 1
Unit 2
Compressor
rotation speed
Outdoor fan
Heating output
Cooling output
Defrosting signal
Request
Re
versing valv
e
Oper
ation
Compressor
Turns on for
cooling
Balancing period 3min.
Balancing period [TDF414] sec.
Auto-fresh inhibit period 15min.
DEFMAX
Reverse cycle period (max. 12 minutes)
TSKTM2
SDRCT2
WMAX1
WMAX2
WMAX3
30sec.
30sec.
80sec.
Hold
Hold
DFCTPS$
DFPSMX$
DFSPPS$ Pulse
30sec.
15sec.
Defrosting sequence
DFSTEP min
-1
/
TDFSPT sec.
Defrosting request
Balancing request
Balancing request
Unit 1
Unit 2
Electr
ic e
xpansion v
alv
e
480
0
480
0
520
520
MODEL RAM-55QH4
Содержание RAM-55QH4
Страница 31: ... 30 CAPACITY DIAGRAM RELATED TO THE PIPING LENGTH MODEL RAM 65QH4 ...
Страница 37: ...CIRCUIT DIAGRAM MODEL RAM 55QH4 39 L C023 C022 C002 C001 C025 C024 N ...
Страница 38: ...CIRCUIT DIAGRAM MODEL RAM 65QH4 41 L C023 C022 C002 C001 C025 C024 N ...
Страница 41: ... 45 ...
Страница 47: ... 53 Outdoortemperature STAROTP_C TSKTM1_C1 Outdoortemperature STAROTP_C TSKTM1_C2 ...
Страница 48: ... 55 ...
Страница 49: ... 57 ...
Страница 50: ... 59 ...
Страница 51: ... 61 ...
Страница 69: ... 79 5A ...
Страница 76: ... 86 ...
Страница 92: ... 105 ...
Страница 93: ... 106 ...
Страница 99: ... 112 TROUBLESHOOTING OF THE SYSTEM POWER MODULE ...
Страница 100: ... 113 ...
Страница 101: ... 114 ...
Страница 103: ... 116 three three inlet 3 Cut off the three pipes at the side and bottom of Reversing valve ...
Страница 104: ... 117 ELECTRIC EXPANSION VALVE PIPE THERMISTOR POSITION CHARTS MODEL RAM 55QH4 MODEL RAM 65QH4 ...
Страница 109: ...HITACHI PM NO 0217E Printed in Malaysia RAM 55QH4 RAM 65QH4 ...