Hitachi RAM-60QH4 Manuel De Service page 56

MODEL RAM-60QH4
◇ Expansion valves
• The expansion valves are initialized when power is supplied. The valve for unit 1 is fully closed (520
pulses), and then that for unit 2 is fully opened (480 pulses). When the valve for unit 1 is fully closed
(0 pulse), start-up is possible.
• The start openings are held during the steady speed period when the compressor is started. After the
steady speed period is finished, the TD control is entered. The start openings are set to PSTARTH when
the outdoor temperature at start 40˚C or more, and to PSTART when it is less than 40˚C.
◇ Compressor rotation speed
• When the compressor is started, the SDRCT1 speed / TSTKTM1 second is held.
After the steady speed period is finished, the speed increases at the rate of SDSTEP speed / TSKSPT
second until the target speed is reached.
Power
Unit 1
Unit 2
Heating output
Cooling output
Turns on
for cooling
Turns on
for heating
Outdoor fan
Operation
Rush-in
prevention
Power
approx. 100ms
Compressor
rotation speed
Hold
520
480
Unit 1
0
Hold 500ms Hold 500ms Hold 500ms
Hold Hold
520
480
Unit 2
0
※ TSKTM1, SDRCT1, SDSTEP, TSKSPT, CMAX2, PSTART and PSTARTH are EEPROM data.
1s
1s
1s
100ms
TSKTM1-C
Start enabled
SDRCT1-C
31.25pps 31.25pps
「Outdoor temperature ≧ 40˚C」PSTARTC2K$
Hold Hold
Initialization finished
「Outdoor temperature ≧ 40˚C」PSTARTC2K$
Hold
Hold 500ms
Cooling
Cooling
Start sequence
SDSTEP min
sec.
< TD control + ∆N correction + distribution control >
PSTARTC2$
< TD control + ∆N correction + distribution control >
PSTARTC2$
– 68 –
CMAX2
-1 / TSKSPT