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During the ON phase, the number of fans that are switched on in comparison to the number of those present is a
function of the value set for parameter Fn24.
If a condensation probe has been allocated, the fan control will be in steps with a neutral zone in function of the
value of the condensation probe and the set times.
Fan regulation can be done independently of the compressor or upon request of the compressor in function of the
parameter Fn10 (operation on compressor request): if Fn10=0 condensation control is independent of the
compressor, if Fn10=1 instead, if all of the available compressors are off, the fan is off.
The minimum cut-off is bypassed for time set for parameter Fn14 from switching on the compressor. During this
period, if the regulator requests the fans to switch off, they will be controlled at the minimum speed (one step).
The main function of the regulator with a neutral zone consists in activating/deactivating a number of resources
(discrete power steps) linked to the time in which the delivery probe takes on values outside of the symmetric
proportional band in comparison to the set point value.
For the cooling mode, for example, when the value read by the delivery probe exceeds the SET POINT+(BANDA)/2
threshold value, if the increasing interstep time (set with FN16) has already expired, an increase in power is
implemented and the FN16 time is recounted (increasing interstep time). If the value read by the delivery probe
remains in this range, an additional power increase is activated for each “increasing interstep time” (set with FN16).
The operation is similar for switching off, with the times set by parameter FN17 (decreasing interstep time). Within
the PROPORTIONAL BAND, no variation in power is required.
Hysteresis is not included in this algorithm
.
The addition and removal of power steps must respect the activation and release times between resources
Fn16
and
Fn17
that are loaded upon their activation/release. In case of Neutral Zone regulation, the position of the Setpoint is
always central, independently from the value of the parameter St01. An example is shown below:
Summary of Contents for EWCM 4120
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