Temperature Control; Restrict Of Compressor Starting; Condition And Priority Of Comp. Operation Mode; Control Specification - Panasonic MDF-DU702VH Service Manual

Control specification

１．Temperature control
(1) Outline
This unit controls two comp.s on the H side and the L side in cooperation, and controls the temp. inside
the refrigerator to the set temp. (two-way freezing).
Furthermore, since the two comp.s are of inverter type and the number of revolutions can be changed,
PID control is used in the vicinity of the set temp. inside the compartment.
(2)
Setting（user）
Item
Chamber temp.
Compressor delay
(3)

Restrict of compressor starting

・ Immediately after turning on the power supply or immediately after recovery from power failure, do not
start the compressor for the compressor delay time.
・ When stopping the compressor, do not start for 3 minutes.
(4) Compressor mode
Name
NORMAL
ON
OFF
(5)

Condition and Priority of comp. operation mode

・
The condition and the priority of comp. operation mode as following bellow table.
When the state overlap, the comp. operation mode is determined by the priority.
For each state、
・
For the power failure and demo mode, both are same comp. running operation mode. So, they are
coedited as same level.
・
Test Program and capirariy heater control are not run within being higher priority condition.
If higher priority condition starts, these are stopped.
Priority Condition
High Power failure, Demo mode
Security operation （ There is also priority in
this）
Test Program
Capi heater control
Low Other than those above
Comp.Control in service menu
Set range
-90 ℃～ -50 ℃
3 min～ 15 min
Action
Temperature control by NORMAL
MODE
Basically it is the same as NORMAL
model, and both comp.s are always
ON without temp. control. The
rotational speed is maintained constant
speed operation
Both comp.s are always OFF
-25-
Default
-80 ℃
3 min
Condition
During normal operation
During security operation (chamber
temp. unknown)
Demo mode, Power failure
Security operation (comp. protection
temp. alarm)