ENG
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intake probe (air on) Sr error: MPXone starts control based on the outlet probe Sm alone, considering
a new set point (St*) determined by the formula:
If night-time operation has been set with the intake probe as the control probe, the controller considers
/4=100 and uses the outlet probe. The new set point becomes:
Note:
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if ro=0 the function is not active;
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for night-time operation the new set point is added to the value defined by r4 (= automatic night-
time set point variation);
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in the event of errors on both probes, the controller switches to duty setting operation.
Example
Sm fault in daytime operation, with /4=50, St=-4, Sr=0, Sm=-8, ro (recommended) = 0-(-8) = 8. Then the
new control probe will be Sr with:
St*= -4+8 (100-50)/100=0.
If the fault is on Sr, the new control probe will be Sm with:
St*= -4-8 ·50/100=-8.
ON time for duty setting operation (par. c4)
Duty setting is a special function used to maintain control in emergency situations with errors in the
temperature control probes, until a service intervention. In the event of a temperature probe error,
MPXone uses the other probe available and adjusts the set point according to the setting of parameter
ro. In the event of errors on both probes, MPXone switches to a special mode called “duty setting”. The
controller is activated at regular intervals, operating for a time equal to the value set for the duty setting
parameter c4, and off for a fixed time of 15 minutes.
Code Description
Def Min Max UOM User
User
terminal
c4
ON time for duty setting operation (Toff = 15 minutes fixed)
0 = compressor/valve always OFF
100 = compressor/valve always ON
0
0 100 min
M
NO
Fig.5.o
Ref.
Description
R
Control
c4
ON time
Ref.
Description
t
Time
With duty setting active, during the ON time the solenoid/compressor icon remains on, while it flashes
during the OFF time.
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| 5. Functions
0300086EN rel. 1.0 – 04.09.2018
