Evco c-pro nano RACK User Manual download pdf (Page 60)

C-PRO NANO RACK E C-PRO MICRO RACK APPLICATION MANUAL

Page 60

6.5 Adjustment of condensation

The management of condensation foresees control through discharge pressure fans: according to the type of

control (sideband control or neutral zone control) and according to the use or disuse of the inverter for a finer

adjustment, four types of adjustment are considered.

6.5.1 Sideband adjustment

Sideband control uses the characteristics of the PI regulators (proportional and integral) or the P regulators

(proportional) to establish when to plug in or unplug the fans used, in order to regulate the turn-on or the

shutdown of the various devices inside the differential band.

The parameters relative to the first circuit are the following:

- SPF1 = Setpoint fans (SP)

- PF14 = Type of adjustment = 0

- PF16 = Integral time (TI)

- PF17 = Lateral band (BP)

- PG41 = Number of fans

The number of fans supplies the Maximum Number of Steps with which the proportional band is divided.

The purpose of the PI adjustment is to obtain a null error in this scheme.

The above figure shows the behavior of the band adjustment (SP, SP +BP). Based on the value of the discharge

pressure, the adjustment adds or subtracts the number of fans to be requested. In this adjustment, the band is

found entirely on the setPoint.

It is possible to choose if the control will refer to the PI adjustment or only to the P adjustment, by setting the

parameter for the integral action, which is the integration time (Ti). Specifically, if this parameter is set to the

value of zero, the adjustment is only proportional, otherwise, it also becomes integral. The Ti corresponds to the

time needed by the integral action to become equal to the proportional action, in the hypothesis of a constant

error: the speed of such action is proportionally linked to the value of the integration time. The default

parameter is 600 seconds, so the adjustment uses the proportional + integral characteristic.

As for the compressors, even with the sideband adjustment of the fans it is possible to improve the behavior of

the adjustment band, using the parameter PF78 Sideband steps overlapping factor.

SP SP + BP

Fans

Max fans

Discharging

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Evco c-pro nano RACK User Manual Page 60