Forced Cooling; Execution Condition; Operation Status - Hitachi RAM-71QH5 Service Manual

MODEL RAM-71QH5

FORCED COOLING

In order to accumulate refrigerant, units operate in cooling cycle.
Execution condition and operation status are shown below.

[Execution condition]

With neither indoor unit 1, 2, 3 and 4 not operated, when forced cooling switch is turned ON, forced cooling will be
performed.
Always operation status of indoor units are monitored and forced cooling is inhibited when operation of any unit is detected.

[Operation status]

Outdoor unit fan: Fixed in LO.
Compressor rotation speed: Fixed in 3000min
Expansion valve/reversing valve : Set in normal conditions.
[Note]
During forced cooling, if failure occurs in outdoor unit, thermostat is turned off. However, it is not counted.
Since rotation speed of compressor is fixed in 3000min
not performed.
The following shows the operation state of forced cooling.
Power
Service switch
Unit 1
Unit 2
Unit 3
Unit 4
Operation
Rust in prevention
Power
Turns on
for heating
Outdoor fan
Compressor
rotation speed
100ms
520
480
0
520
480
0
520
480
0
520
480
0
TSKTM1_C and PSTARTC2$ are EEPROM data.
.
-1
1S 1S
100ms
Initialization
-1 during forced cooling, steady speed period of compressor at start is
Forced cooling request
Forced cooling request
Forced cooling request
Forced cooling request
1S
[TSKTM1_C ]
*
<Td control + N compensation + Diving control>
[PSTARTC3 ]
*
<Td control + N compensation + Diving control>
[PSTARTC3 ]
*
<Td control + N compensation + Diving control>
[PSTARTC3 ]
*
<Td control + N compensation + Diving control>
[PSTARTC3
– 46 –
Balancing request
Balancing request
Balancing request
Balancing request
15 sec
Balancing period 3 min
80 sec
Hold
Hold
Hold
Hold
]
*