Mitsubishi Electric CAHV-P500YB-HPB, Service Handbook

Page: 99 / 169

[
VII
Control ]
- 92 -
HWE15070 GB
-7- LEV in the main circuit
Operating range of the LEV
The opening range of the LEV is between 100 and 2000 (fully open).
LEV operation speed
 Open 133 plus/sec
 Close 200 plus/sec
At startup
 For one minute and thirty seconds after startup, the valve will be fixed to the Initial Setting.
During operation
 Ninety or more seconds after startup, the LEV opening will be controlled every 30 seconds according to the changes in com-
pressor frequency, pressure, and temperature.
 The LEV will be controlled to keep the shell bottom SH in the range between 20 and 25K.
 If the outside temperature reaches 17ºC or above, the MOP function will be triggered to keep the low pressure from rising too
high.
(The LEV opening will be decreased to keep the low pressure at or below 1 MPa.)
 When the outside temperature is high and the water temperature is low (water temperature below 35ºC), the function to keep
the low pressure from rising too high will trip.
(The LEV opening will be decreased so that the compression ratio of 1.5 or above will be maintained.)
Refrigerant Recovery Control
-8- Operation during power failure
Duration of power failure 20 ms or shorter 20 ~ 200ms 200 ms or longer
Detection of power failure Undetectable Instantaneous power
failure
Detection of power failure
Operation during power failure Normal
operation
During an instanta-
neous power failure,
the unit will be con-
trolled according to
the input status of
the circuit board im-
mediately before the
instantaneous power
failure.
All outputs will be turned off immedi-
ately after power failure.
Operation
after power is
restored
Automatic restoration
after power failure is set
to "Enabled" (SW3-2 is
set to ON.)
Normal
operation
The circuit board will
start receiving input.
The unit will be controlled according to
the input status of the circuit board im-
mediately before the power failure, ex-
cept that the input status of the dry
contact after the power is restored will
override the one before the power fail-
ure. For three minutes after the power
is restored, the unit will not operate.
Automatic restoration
after power failure is set
to "Disabled" (SW3-2 is
set to OFF.)
The unit will stop, displaying the error
code for power failure.
The error will be cleared when the op-
eration command signal is off.
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