EVCO c-pro nano RACK User Manual
Page 49
C-PRO NANO RACK E C-PRO MICRO RACK APPLICATION MANUAL
Page 49
Steps will be loaded at PC78% of the proportional band; the steps will be unloaded at 100 – PC78% of the
proportional
band.
If for example PC78 has value 60%, the steps will be loaded between 60% of the proportional band and its
maximum value (100%); steps will be unloaded between 40% of the proportional band and its minimum value
(0%).
It appears clear that by using such a division of the steps as indicated in the image, the interval of activity of
each single step is higher than the classical geometrical division, with the clear advantage that the proportional
band may be diminished, to favor a higher precision of adjustment, and/or the activations of the steps occur less
frequently, that is, the breakaways of the compressors decrease, favoring the mechanical duration of the
compressors themselves.
6.3.2
Neutral zone adjustment
This adjustment implies the definition of a neutral zone in which no decision of activation or deactivation will
be made, which means that no breakaways will be required for any device.
The parameters relative to the first circuit are the following:
7
SPC1 = Setpoint compressors (SP)
8
PC14 = Type of adjustment = 1
9
PC18 = Neutral Zone (NZ)
10
PC19 = Differential outside the neutral zone (diff)
11
PC20 = Minimum time of Turn-on (TOnMin)
12
PC21 = Maximum time of Turn-on (TOnMax)
13
PC22 = Minimum time of shutdown (TOffMin)
14
PC23 = Maximum time of shutdown (TOffMax)
Outside the neutral zone, the turn-on or shutdown requests for the various steps supplied by the compressors
will follow this logic:
1
Turn-on: when the pressure of suction exceeds the threshold value setpoint + neutral zone
2
Shutdown: when the pressure goes below the setPoint
In this type of adjustment, the neutral zone is found entirely to the right of the setPoint.
SP
SP + BP
Gradini
Max Gradini
Aspirazione
PC78 %
Inserimento
Rilascio
SP
SP + e
SP + Zona + diff
SP - diff
TOnMin
TOnMax
TOffMax
TOffMin
Neutral zone
Switching on
Switching off
Suction