Grundfos CONTROL MPC Installation And Operating Instructions Manual page 35

11.7.18 Pump stop attempt (4.2.7)
Fig. 53 Pump stop attempt
Description
The function makes it possible to set automatic stop attempts of a
pump when several pumps are running. It ensures that the
optimum number of pumps is always running, in terms of energy
consumption. See 11.7.19 Pump start and stop speed (4.2.8). At
the same time, the purpose is to avoid disturbances in connection
with automatic stop of pumps.
Stop attempts can either take place with a fixed interval set under
Interval between stop attempts or by self learning. If self
learning is selected, the interval between stop attempts will be
increased if repeated attempts to stop the pump fail.
Setting via control panel
1. Mark the Settings menu with
2. Mark Pump cascade control with
.
3. Mark Pump stop attempt with
4. Mark Self learning or Fixed interval with
press .
5. If Fixed interval is selected:
6. Mark Interval between stop attempts with
7. Set the interval with
8. Mark Activated with
mark in the right box shows that the function has been
activated.
Factory setting
The function is activated, and self learning is selected.
.
or , and press
or , and press
or
or
or , and save with .
or , and press . The check
11.7.19 Pump start and stop speed (4.2.8)
Description
The function controls the starting and stopping of pumps.
There are two options:
1. Use calculated speed
This function ensures that the optimum number of pumps is
always running at a desired duty point, in terms of energy
consumption. The CU 351 calculates the required number of
pumps and their speed. This requires that the differential
pressure of the pump is measured by a differential pressure
sensor or separate pressure sensors on the inlet and
discharge side.
When calculated speed has been selected, the CU 351
ignores the percentages set.
2. Use fixed speed
The pumps are started and stopped at speeds set by the user.
1. Use calculated speed
. Fig. 54 Calculated pump start and stop speed
, and
Setting via control panel
1. Mark the Settings menu with
2. Mark Pump cascade control with
.
.
3. Mark Pump start and stop speed with
.
4. Mark Use calculated speed with
2. Use fixed speed
Fig. 55 Fixed pump start and stop speed
.
or , and press
or , and press
or , and press .
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