Grundfos Control MPC Serie Manual De Instrucciones página 45

System with flow switch
Make the following additional settings:
1. Select: Go to setting of digital input. Display
inputs (4.3.7) appears.
2. Select the digital input where the flow switch is connected.
3. Select: Flow switch.
4. Press [Back].
Fig. 70 System with flow switch
An open contact indicates low flow.
System with flowmeter
Make the following additional settings:
1. Select: Go to setting of analog input. The display
8.7.30 Analog inputs (4.3.8)
2. Select the analog input where the flowmeter is connected.
3. Select: Flow rate.
4. Press [Back] x 2.
Fig. 71 System with flowmeter
5. Set: Stop limit.
As standard, there is a 10-seconds detection
hysteresis.
8.7.28 Digital
appears.
Factory setting
The function is enabled in pressure-boosting applications with the
settings in the table.
Start/stop band: 25 %
Minimum flow rate: 30 % of the rated flow rate of one
pump
Distribution above setpoint: 50 %
The function is disabled in all other applications.
8.7.25 Pilot pump (4.3.2)
Fig. 72 Pilot pump
Description
This function is used in constant-pressure applications to save
energy in low flow situations. The pilot pump is typically Qnom
1/4 of the Qnom on the main pump, thus allowing the system to
run to be more energy efficient at low flow.
Both cut-in and cut-out speed for pilot pump and main pump are
calculated using the pump curve data.
The pilot pump needs to be activated using the PC
Tool. We recommend to upload pump data for the
pilot pump or go to menu and enter them manually.
1. Enable or disable the pilot pump.
2. Changeover to pilot pump
Set the flow for the changeover from main pump to the pilot
pump. Factory settings are 75 % of the pilot pump Qnom.
3. Time hysteresis
Set the delay time for the changeover to a stable low flow
before the changeover.
4. Changeover to main pump
Set the flow for the changeover from pilot pump to the main
pump. Factory settings are 95 % of the pilot pump Qnom.
5. Time hysteresis
Set the delay time for the changeover to a stable low flow
before the changeover.
6. Pressure band cut-in
Set the pressure band in percentage of the setpoint. The
pressure band is used for cut-in or cut-out of pumps
– Main pumps cut-out when the pilot pump ramps up to a
stable setpoint "+ or and" pressure band outlet pressure
– Pilot pump cut-out when the main pumps ramps up to a
stable setpoint "+ or and" pressure band outlet pressure
– If the pilot pump is running at 100 % and the pressure band
is below the setpoint-pressure band, the main pumps will cut
in.
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