Error Handling; Fan Control; Table Auto Mode - Panasonic MDF-DU702VH Service Manual

First at 2500 rpm,
Return to 3000 rpm with cascade temperature below -20 ° C
⑥ Transition conditions from the initial startup period to the constant-speed initial period (OR)
・Initial startup period has passed 120 sec or more
・Other than the conditions below
Extended for 30 sec when the cascade temp. is higher than the threshold (-10 ° C) and the cascade temp.
drop detection.
During the startup period, if the ambient temp. is 32 ° C or more, increase the H rotation to 4000 rpm
⑦ Transition conditions to constant speed initial period or constant speed period
・Detect maximum peak value of the cascade temp. and it is -30 ℃ or less.

【Error handling】

If the following conditions occur, reset the microcomputer once
・Command failure occurred 20 times consecutively
If the above condition occurs even after resetting the microcomputer, it outputs a communication failure
warning.
If the communication failure is canceled, the alarm is canceled.
【Addition】
If the following condition (AND) under the constant speed period and the forced-ON mode,
change the L side rotational speed from 3000 to 3150.
･Set temp. is -86 °C or less
･Chamber temp. is -83 °C or less (return to 3000 rpm at -82 °C over)
If the following conditions, change the rotation speed during PID control from 3000 to 3150.
･Set temp. is -83 °C or less
３．Fan control
(1) Control
The fan is operated in the following mode against the compressor operation.
table FAN operation mode
Name
A_ON
A_OFF
AUTO
※１Temporary setting in manufacturing process and service work.
Then, the state transition of AUTO mode is shown in the table below.
・ FAN_OFF : 31℃（Ambient temp. measurement value）
FAN_ON : 32℃（Ambient temp. measurement value）
① AUTO mode
FAN_ON≦T
FAN_OFF<T<FAN_ON refer to ※2 T≦FAN_OFF

Table AUTO mode

State
No. FAN
C11 Stop
C12 Run
Control policy
※2
If it does not match either state of link with comp. or AB_ON, it is compatible with comp.
Operation
Fan is always On
Fan is always Off
Change control according to ambient
temp.
both A and B,ON
T≦FAN_OFF
Link with H comp. ※2
Link with H comp. ※2
Link with H comp. ※2
Condition
When On is set by FAN control※1
When Off is set by FAN control※1
Normal
When Auto is set by FAN control
Link with comp.
Chamber temp.(T)
FAN_OFF<T<FAN_ON
※2
※2
none
-27-
FAN_ON≦T
ON C12
(none) ―
Always ON