Grundfos CU 301 Instrucciones De Instalación Y Funcionamiento página 9

Figure Principle of mains borne signalling (power line
communication) shows the principle of mains borne
signalling between CU 301 and the pump.
CU 301
1
2
3
8
7
Principle of mains borne signalling (power line
communication)
Pos. Description
1 Supply to the electronics
2 Signal coils
3 Capacitor
Electronics for the control of the
4
communication
5 On/off button
6 Sensor signal
7 Power supply
8 Communication signals
9 Grundfos GO Remote
5
4
9
6
When does the pump start
The pump starts as a consequence of the following:
• a high flow
• a low pressure
• a combination of both.
To ensure that the pump starts when water is
consumed, a flow detection is required. The flow is
detected via pressure changes in the system. When
water is consumed, the pressure drops accordingly
depending on the size of the diaphragm tank and the
water flow:
• at a low flow, the pressure drops slowly.
• at a high flow, the pressure drops quickly.
1
4
Pos. Description
1 Pressure
2 Low flow
3 Time
4 High flow
When the pressure drops 0.1 bar/s or faster, the
pump starts immediately.
If a diaphragm tank of 8 litres is used, the pump starts
at a flow rate of approximately 0.18 m
tank is used, the flow must be higher before the pump
starts.
Consumption up to 0.18 m
The pump starts when the pressure drops to 0.5 bar
below the pressure setting.
The pump runs until the pressure is 0.5 bar above the
pressure set.
Flow detection
During pump operation, meaning when water is
consumed, CU 301 adjusts the pump speed to
maintain a constant pressure. In order to stop the
pump when no water is consumed, CU 301 performs
flow detection every 10 seconds.
2
3
3
/h. If a larger
3
/h
9