VARISCO PSDrive 11, Инструкция по установке, эксплуатации и обслуживанию

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Parameter Default Description
EEPROM writing
ON/OFF
OFF Setting the writing mode of the parameters transmitted via MODBUS:
ON : The data is saved in EEPROM
OFF : The data is not saved in EEPROM
Change PASS-
WORD1
Press ENT
The ENT key may be used to change the installer level password (level 1) (default 001).
10. Constant pressure operation
10.1. Introduction
The PSDrive can manage the rotation speed of the pump in such a way as to keep the pressure con-
stant as the water demand changes. A pressure sensor placed as close as possible to the pump is
used for this purpose.
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2
3
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5
6 7
1: Inverter; 2: Pump; 3: Check valve; 4: Pressure tank; 5: Valve; 6: Valve; 7: Pressure sensor
NOTE
If the suction pressure is expected to drop below atmospheric pressure during operation,
absolute rather than relative pressure sensors must be used.
10.2. The pressure tank
In water systems equipped with inverters, the pressure tank has the sole function of compensating for
losses (or minimum water consumption) and maintaining pressure when the pump is stopped, thus
avoiding excessively frequent start/stop cycles. It is of fundamental importance to correctly choose the
volume and the pre-charge pressure of the pressure tank. Too small volumes do not allow to effectively
compensate the minimum water consumption or the losses when the pump is stopped, while too high
volumes cause difficulties in the pressure control operated by the inverter.
It is generally sufficient to place a pressure tank with a volume of about 10% of the maximum flow rate
required, considered in litres/minute.
Example
If the maximum flow rate required is 60 l/min, it is sufficient to use a 6 litre pressure tank.
The pre-charge pressure of the pressure tank must be approx. 80% of the operating pressure.
Example
PSDrive
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