8 Commissioning/Shutdown
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PumpDrive 2
Several master control devices can be assigned to improve the availability of the
multiple pump system. One of them serves as the active master control device, while
the others act as redundant devices. The active master control device is identified by
an "M" for "master" in the second header of the control panel. In the event that the
active master control device fails, its tasks will be assumed by a redundant master
control device. To ensure that this takes place, all signals required for open-loop and
closed-loop control must also be connected to the redundant master control devices.
NOTE
If the master control device fails and a redundant master control device assumes its
tasks, a temporary drop in pressure can occur.
The maximum number of pumps running simultaneously is limited via the Maximum
Number of Pumps Running parameter (3-7-2).
Table58: Multiple pump configuration parameters
Parameter Description Possible settings Factory setting
3-7-1 Role in Multiple Pump System
Selecting the role of the frequency inverter
in a multiple pump configuration. The
active master control device is responsible
for starting and stopping pumps, as well as
for open-loop and closed-loop control. All
input variables required for open-loop or
closed-loop control must be connected to
the master control device and all redundant
master control devices. The redundant
master control device which is to serve as
active master control is selected
automatically based on a configurable
transfer time. Auxiliary control and
redundant master control devices receive
the control value from the master control
device.
▪ Master Control
▪ Auxiliary Control
Master Control
3-7-2 Maximum Number of Pumps Running
Maximum number of pumps running
simultaneously in a multiple pump
configuration
0...6 1
8.7.2.2.2 Starting and stopping
NOTE
System flow rate availability is a prerequisite for starting and stopping pumps. If the
flow rate has not been measured, flow rate estimation, parameter 3-9-8-1, must be
enabled.
Pumps are started and stopped in line with current requirements via the switching
limits displayed in diagrams 1 and 2. If the current operating point of the multiple
pump system shifts such that one of these switching limits is passed, a pump is started
or stopped. Switching limits are defined using the parameters listed in the "Start/stop
parameters" table. These switching limits are parameterised for changing over from
one to two pumps. Switching limits for starting and stopping additional pumps are
calculated automatically and do not need to be defined.
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