Operating Mode (1.2 - Grundfos CONTROL MPC Installation And Operating Instructions Manual

11.4.3 Operating mode (1.2.1)

Operating mode
Fig. 9
Description
Here the operating mode of the system is shown as well as from
where the Control MPC is controlled.
Operating modes
Control MPC has six operating modes:
1. Normal
The pumps adapt their performance to the requirement.
2. Max.
The pumps run at a constant high speed. Normally, all pumps
run at maximum speed.
3. User-defined
The pumps run at a constant speed set by the user. Usually, it
is a performance between Max. and Min.
4. Min.
The pumps run at a constant low speed. Normally, one pump
is running at a speed of 70 %.
5. Stop
All pumps have been stopped.
6. Emergency run
The pumps run according to the setting made in the display
Emergency run (4.3.5).
The performance required in the operating modes Max., Min.,
User-defined and Emergency run can be set in the Settings
menu. See sections 11.7.33 Min., max. and user-defined duty
(4.3.14) and 11.7.25 Emergency run (4.3.5).
The current operating mode can be controlled from four different
sources: Fault, External signal, CU 351 and Bus.
Control source
Control MPC can be set to remote control via an external bus
(option). In this case, a setpoint and an operating mode must be
set via the bus.
In the Settings menu, it is possible to select whether the CU 351
or the external bus is to be the control source.
The status of this setting is shown in the display Operating
mode.
16
11.4.4 Setpoint (1.2.2)
Fig. 10 Setpoint
Description
This display shows the selected setpoint and whether it comes
from the CU 351 or an external bus.
The display also shows all seven possible setpoints from CU 351
(for closed- and open-loop control). At the same time, the
selected setpoint is shown.
As it is a status display, no settings can be made.
Setpoints can be changed in the Operation or Settings menu.
See section 11.7.3 Alternative setpoints (4.1.2).
11.4.5 Setpoint influence (1.2.3)
Fig. 11 Setpoint influence
Description
The selected setpoint can be influenced by parameters. The
parameters are shown as percentage from 0 to 100 % or as a
pressure measured in bar, They can only reduce the setpoint, as
the influence in percentage divided with 100 is multiplied with the
selected setpoint:
Setpoint Setpoint
=
( )
current SP
The display shows the parameters influencing the selected
setpoint and the percentage or value of influence.
Some of the possible parameters can be set in the display
External setpoint influence (4.1.3). The parameter low flow boost
is set as an on/off band as a percentage of the setpoint set in the
display Stop function (4.3.1). The parameter is set as a
percentage in the display Proportional pressure (4.1.7).
Finally the resulting current setpoint (SP) is shown.
× Infl. 1 ( ) × Infl. 2 ( ) ×
...
selected