Pilot Pump (4.3.2) - Grundfos Control DDD Montage- Und Betriebsanleitung

A B
Stop
Start
Stop: Hset + 0.5 x start/stop band
Start: Hset - 0.5 x start/stop band
Fig. 72 On/off operation
The flow rate is measured by CU 354 when the pump is in the
stop period. As long as the flow rate is lower than Qmin, the pump
runs in on/off operation. If the flow rate is increased to above
Qmin, the pump returns to normal operation, Hset. Hset is equal
to the actual setpoint. See section
Detection of low flow rate
Low flow rate will be detected by:
• direct flow measurement with a flowmeter.
A diaphragm tank of a certain size and with a certain precharge
pressure is required.
Diaphragm tank size
Recommended diaphragm tank size
Pump type
-E
CRI, CRIE 3 8
CRI, CRIE 5 12
CRI, CRIE 10 18
CRI, CRIE 15 80
CRI, CRIE 20 80
CR, CRE 32 80
CR, CRE 45 120
CR, CRE 64 120
CR, CRE 90 180
CR, CRE 120 180
CR, CRE 150 180
Precharge pressure
For the whole DDD system, 0.7 x the setpoint.
The minimum flow rate can be set, that is the flow rate at which
the DDD system changes to on/off control of the last pump in
operation.
Setting range
Start/stop band:
Minimum flow rate:
Distribution above setpoint:
Setting via operating panel
• Settings > Secondary functions > Stop function
1. Set: Enabled.
2. Select: Go to setting of analog input
The display 8.7.28 Analog inputs (4.3.8)
3. Select the analog input where the flowmeter is connected.
4. Select: Flow rate.
A: Normal operation
B: Pressure boosting
C: Stop
C B C
Setpoint (1.2.2).
[litres]
-F -S
8 80
12 120
18 180
80 300
80 400
80 600
120 800
120 1000
180 1500
180 1500
180 1500
5-30 %
2-50 % of the rated flow rate
(Qnom) of one of the pumps.
It can be set if direct flow
measurement by means of
flowmeter has been selected.
0-100 %
appears.
5. Press x 2.
6. Set: Start/stop band.
7. Set: Stop limit
By default, there is a 10-second detection hysteresis.

8.7.23 Pilot pump (4.3.2)

Fig. 73 Pilot pump
Description
The function is used to save energy in low flow situations. The
pilot pump is typical Qnom 1/4 of the Qnom on the main pump,
thus allowing the system to run more energy efficient at a low
flow.
Both cut-in and cut-out speed for pilot pump and main pump are
calculated using the pump curve data.
Pilot pump needs to be activated using PC Tool. We
recommend uploading pump data for the pilot pump
or go to the menu
(4.3.18)
1. Enable/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
– Time hysteresis
Set the delay time for the changeover to a stable low flow
before the changeover.
3. 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.
– Time hysteresis
Set the delay time for the changeover to a stable low flow
before the changeover.
– Pressure band cut-in
Set the pressure band in percentage of the setpoint. The
pressure band is used for cut-in/cut-out of pumps
– Main pumps cut-out when then pilot pump ramps up to a
stable setpoint "+ or and" outlet pressure
– Pilot pump cut-out when the main pumps ramps up to a
stable setpoint "+ or and" outlet pressure
– Or if the pilot pump is running at 100 % and the pressure
band is below setpoint-pressure band the main pumps will
cut in.
Setting via the operating panel
• Settings > Secondary functions > Pilot pump.
1. Enable pilot pump
– Set: Changeover to pilot pump
– Set: Time hysteresis
– Set: Changeover to main pump
– Set: Time hysteresis
2. Set: Pressure band cut-in
8.7.35 Pilot pump curve data
39