Defrost Operation Ras-3Hvrc2 - Hitachi UTOPIA RAS-4HVRP2E Service Manual

5 Control System
Standard operation sequence RAS-3HVRC2 and RAS-(4-6)H(V)(R/N)(C/P)2E

5.5.4 Defrost operation RAS-3HVRC2

Heating
Operation
Start Condition is
Defrost Operation
Defrost Operation
Defrosting
Stop Condition is
approved
No
100 SMGB0136 rev.0 - 07/2021
No
(Y52H) Energize
Defrosting
Yes
approved
Compressor
(MC) Stop
Indoor
suction, Air
temperature
Yes
Thermo settings
Less than preset
temperature
Operation at Slo Fan
MIF
Speed
Operation at Low Fan
MIF
Speed
(*) Refer to Service Manual for the timing diagram of the reversing valve.
Four-way valve (21)
Energization OFF
(52H) Energize
Compressor
Elapsed
time 30 s (MC) Operation
Yes
No
Thermo settings
Temperature +2°C or higher
< 77°F
≥ 86°F
(25°C)
IU Air
(30°C)
Outlet Temp.
≥ 77°F (25°C) and
< 86°F (30°C)
I.U: Indoor Unit
: Actuator
Display during
defrosting
Auxiliary Electric heater (H)
operation
Indoor fan (MFE) Stop
Outdoor fan (MFC) Stop
Four-way
valve (21)
Energization ON
(*)
Display disappears
during defrosting
Indoor fan in slow
wind speed
Compressor MC
Stop
MIF Operation at
Set Fan Speed