Control Mode; Pipe-Filling Function - Grundfos Hydro Multi-E Series Installation And Operating Instructions Manual

12.3 Control mode

Here you can choose between the different control modes.
12.3.1 Constant pressure
We recommend this control mode if the pump is to deliver a
constant pressure, independently of the flow in the system. See
fig. 31.
H
Fig. 31 "Constant pressure"
This control mode uses the factory-fitted pressure sensor, if any,
which measures the outlet pressure of the pump.
For pumps without a factory-fitted sensor, you must connect a
pressure sensor to one of the analog inputs of the pump. You can
set the pressure sensor in the "Assist" menu. See section Assist.
Examples
• One external pressure sensor.
p
Fig. 32 "Constant pressure"
Controller settings
For recommended controller settings, see section
Factory setting
See section 29. Factory settings.
12.3.2 Proportional pressure
For proportional pressure, see 12.9 Proportional
18

12.4 Pipe-filling function

This function is typically used in pressure-boosting applications,
and it ensures a smooth startup of systems with, for instance,
empty pipes.
Startup takes place over two phases. See fig. 33.
1. Filling phase.
The pipes are slowly filled with water. When the pressure
sensor of the system detects that the pipes have been filled,
phase two begins.
2. Pressure build-up phase.
The system pressure is increased until the setpoint is
reached. The pressure build-up takes place over a pressure
build-up period. If the setpoint is not reached within the given
time, a warning or an alarm can be given, and the pumps can
be stopped at the same time.
Q
Pressure
Setpoint
Filling pressure
p
12.6 Controller.
Fig. 33 Filling and pressure build-up phases
Setting range
• Filling speed
pressure.
Fixed speed of the pump during the filling phase.
• Filling pressure
The pressure that the pump must reach before the maximum
filling time.
• Max. filling time
The time in which the pump must reach the filling pressure.
• Max. time reaction
Reaction of the pump if the maximum filling time is exceeded:
– warning
– alarm (pump stops).
• Pressure build-up time
Ramp time from when the filling pressure is reached until the
setpoint must be reached.
Factory setting
See section
1. Filling phase 2. Pressure build-up phase
(constant-curve (constant-pressure
operation) operation)
Actual value
Filling time
Pressure
build-up time
Maximum filling time
When you activate this function, the function always
starts when the pump changes from operating mode
"Stop" to "Normal".
29. Factory settings.
Setpoint
ramp-up
Time
[sec]