Parameter
Default
Description
MODBUS data format
XXXXX
RTU
N81
MODBUS data format: RTU N81, RTU N82, RTU E81, RTU O81
MODBUS EEPROM
write
ON/OFF
OFF
Setting the writing mode of the parameters transmitted via MODBUS:
ON: the datum is saved in EEPROM
OFF: the datum is not saved in EEPROM
Change password1
Press ENT
By pressing the ENT key it is possible to change the installer level password (level 1) (default 001).
9.10. Pump stop under low irradiation conditions
Centrifugal pumps develop the head in relation to their running speed (frequency). If irradiation is too weak, the
pump may continue to operate without generating flow since the developed head is lower than the minimum head
necessary to produce the flow.
Since the water flow is responsible for cooling the motor (submerged) and the pump, the persistence of this
condition would lead to dangerous overheating of the motor (submerged) and of the pump.
9.10.1. Minimum frequency stop
Parameter Min motor frequency ca be set from the menu Motor parameters at a sufficiently high value to ensure
that the pump stops below a certain frequency, according to the formula:
f min = f max ⋅
H min
H max
+ 2
(1)
• f min [Hz]: Min motor frequency
• f max [Hz]: Max motor frequency
• H min [m]: head of the system at minimum frequency (static head)
• H max [m]: maximum head of the pump (at zero flow) at maximum frequency. It is generally available in the
pump data plate.
• 2 [Hz]: variable safety factor between 2 and 5 Hz.
9.10.2. Shutdown due to minimal irradiation
If a solarimeter is connected to digital input 2, it is possible to set parameter Min stop irradiation from the menu
IN/OUT parameters at a value below which the pump will be stopped after 60 seconds of operation. The device will
attempt to restart the pump every XX minutes based on the value specified in parameter Restarts delay.
9.10.3. Stop for minimum flow
It is possible to stop the pump if the flow rate falls below the value set in parameter Min stop flow.
The flow measurement mode is set in the menu IN/OUT parameters through parameter Flow Measure.
9.11. Control by flow switch
In control mode MPPT , a flow switch can be connected to the device to stop the operation of the pump in the
presence of zero flow or in conditions of low irradiation, when the head developed by the pump is not sufficient,
or when the delivery is closed. The flow switch, potential-free contact, must be connected to digital input 2 or to
terminals 0V, IN2.
The programming of the device, needed to implement the flow switch control, is based on the following parameters:
Menu
Parameter
Description
IN/OUT parameters
Digital input 2
Configuration of digital input 2, to which the flow switch is connected, as Normally
Open (pump running with open contact) or Normally Closed (pump running with
closed contact).
IN/OUT parameters
Dig. input 2/3 delay
By setting a value higher than 30 seconds, the device will stop the pump if the flow
is zero for more than XX seconds. The pump will restart as soon as the flow switch
detects new flow.
Control parameters
Restarts delay
Every XX minutes (default 5 minutes) the inverter will try to restart the pump even if
the flow switch detects no flow. If flow is re-established, the pump will continue to run.
If the flow remains zero for longer than the delay set for digital input 2, the inverter will
stop the pump again.
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Содержание SUND
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