Mitsubishi Electric QAHV-N560YA-HPB, Service Handbook

Page: 113 / 176

[
VII
Control ]
- 106 -
HWE1517A GB
Startup sequence rotation
-2- Initial control
 When the power is turned on, the initial processing of the microcomputer is given top priority.
 During the initial processing, processing of the operation signal is suspended and is resumed after the initial processing is
completed.
(Initial processing involves data processing by the microcomputer and initial setup of the LEV opening. This process takes up
to two minutes.)
 During the initial processing ” ” will appear on the LED monitor on the MAIN board.
Initial Control
-3- Compressor frequency
 The maximum frequency will be determined based on the relationship between the water temperature and the outside tem-
perature as well as the ON/OFF status of the Energy-save/Maximum capacity contact.
(The values not on listed in the table are interpolated.)
Control at Start-up
-4- Defrost start/end conditions
Defrost start conditions
Defrost begins when conditions 1) through 3) listed below
are all met.
1) Refrigerant temperature at the air heat exchanger inlet
is at or below the value determined in relation to the
outdoor temperature(*2).
2) Cumulative compressor operation time has reached
35 minutes since the completion of the last defrost op-
eration.
3) Cumulative compressor operation time has reached
35 minutes since the operation-ON signal was sent.
Or the outdoor temperature is -15ºC or below and the
compressor shell bottom SH temperature is at or below
the specified temperature.
Defrost end conditions
Defrost ends when any of the conditions 1) through 4) listed below is met.
1) Maximum defrost time (15 minimum) has been reached. Maximum defrost time is 20% of the cumulative compressor
operation time from the last defrost or from the time operation-ON signal was sent.
2) Three minutes have elapsed since the refrigerant temperature at the air heat exchanger outlet reached 4ºC or above.
3) Low pressure has reached 8.5 MPa or above.
4) High pressure has reached 12.0 MPa or above at the frequency of 30 Hz.
5HIULJHUDQWWHPSHUDWXUHDWWKHDLUKHDWH[FKDQJHULQOHWഒ
2XWGRRUWHPSHUDWXUHഒ
'HIURVWVWDUW
FRQGLWLRQ
0000001906.book 106 ページ ２０１８年７月１９日 木曜日 午前７時２２分