SJE Rhombus VARIOspeed LCD Manual De Inicio Rápido página 8

Parameter List
3. Advanced Pumping Functions
Pre-charge Frequency (P. 127)
The Pre-charge function should be used for pumping applications where a slow fill of the piping system is required to
reduce water hammer. The Pre-charge Frequency should be set to the frequency at which the VFD will operate while in
Pre-charge mode. Default value: 30 Hz
Pre-charge Ending Level (P. 761)
The Pre-charge Ending Level should be set to the system pressure at which the VFD will exit the Pre-charge function
and start the normal pressure control operation. Default value: 9999 (disabled)
Pre-charge Ending Time (P. 762)
The Pre-Charge Ending Time should be set to the maximum amount of time in which the VFD will operate in Pre-charge
mode before starting the normal pressure control operation. Default value: 9999 (disabled)
Caution! Always set Pre-charge pressure (P.761) below the pressure set point (P.133). It is recommended for
the Pre-charge pressure to be set at least 20PSI below the pressure set point, even when only using Pre-charge timer.
PID Output Hold (P. 1361, P. 1362)
PID Output Hold is used to reduce the power consumption of the VFD by eliminating unnecessary acceleration and
deceleration during relatively stable flow conditions. The VFD accomplishes this by monitoring the deviation of the sys-
tem pressure, called the PID Output Hold Range, compared to the Set Pressure. If only a small deviation from the Set
Pressure is detected, the output frequency is held constant after the Detection Time for PID Output Hold period of time.
The PID Output Hold function will exit once the system pressure falls outside of the PID Output Hold Range, compared
to the Set Pressure, after the Detection Time for PID Output Hold period of time.
P. 1361 - Detection Time for PID Output Hold
The Detection Time for PID Output Hold is the delay time that the VFD will wait before entering or exiting the PID Output
Hold function. The Detection Time for PID Output Hold is measured in seconds. Default value: 5 sec
P. 1362 - PID Output Hold Range
The PID Output Hold Range is measured in the percentage of the scaled pressure transducer. For example, if the pres-
sure transducer used has a full scale value of 200 psi and a ±2 psi deviation from the Set Pressure is desired for the
PID Output Hold function, then the PID Output Hold Range would be set to "1.0" (±Deviation ÷ Transducer Scale * 100
 2 ÷ 200 * 100 = 1.0). Default value: 9999 (disabled)
Detection time for PID output hold
Set Point
Output
Frequency
8
(Pr.1361)
Deviation
System Pressure
PID output is held.
Detection time for PID output hold
(Pr.1361)
VARIOspeed
PID output hold range (Pr.1362)
Time
Time
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