time delays for the analog inputs have an identical value for all the PumpDrives in
the system and, therefore, have to be exclusively set via the active master control
panel.
7.1.3.1
Start and stop parameter settings in multiple pump configurations
▪
In multiple pump configurations, a pump is started when the power input of a
pump exceeds a defined value.
▪
In multiple pump configurations, a pump is stopped when the power input of a
pump drops below a defined value.
The following parameters have to be set in order to specify the limits. If the High
Load Function
(3-6-4-5)
and Low Load Function
(3-6-4-10)
parameters are set to
Warning, the option of starting and stopping PumpDrives in a multiple pump
configuration is enabled. High load and low load warnings cause pumps to be started
and stopped in the system as required. The speed range of the pump is defined by
means of the low motor frequency limit Freqency Lo
(3-6-1-2)
(e.g. 25 Hz) and the
high motor frequency limit Freqency Hi
(3-6-1-3)
(e.g. 50 Hz). The power parameters
required for starting and stopping
3-6-4-1
/
3-6-4-2
/
3-6-4-6
/
3-6-4-7
are referred to
the nominal motor power and define at which power level, referred to the speed,
the high load or low load warning is output. This warning corresponds to the start
and stop command. Depending on the pump size and pump type, the parameters for
the speed and power may have to be adapted in order to achieve optimal starting
and stopping in the system. The Tm Cons Add Pum
(3-12-5-3)
and Tm Stop Pump
(3-12-5-4)
parameters allow time delays to be set for starting and stopping pumps in
the system. The time specifications are referenced to the last time when PumpDrives
were started or stopped. If, for example, the Tm Cons Add Pum
(3-12-5-3)
parameter
is set to 5 s, a further pump is started after 5 seconds when another pump was
started in the system beforehand and the High Load warning remains active. If the
multiple pump system is operated under low flow conditions, the pumps are stopped
at the time intervals set for the Tm Stop Pump
(3-12-5-4)
parameter if the Low Load
warning is active. This routing is repeated until only one pump is running.
Note: The Tm Cons Add Pum
(3-12-5-3)
and Tm Stop Pump
(3-12-5-4)
parameters have
to be set to the same value on each Advanced control panel in multiple pump
configurations, as they are local parameters of the individual control panels.
P
max@3--6--1--3
(3--6--4--2)
P
max@3--6--1--3
(3--6--4--7)
P
max@3--6--1--2
(3--6--4--1)
P
max@3--6--1--2
(3--6--4--6)
f
min
(3--6--1--2)
f
max
(3--6--1--3)
Fig. 39: Characteristic curves for defining the start and stop limits in multiple pump
configurations (permissible area is shaded)
The following parameters have to be entered for the main pump only. If PumpDrive
is supplied on its own, the factory settings are suitable for operation of a 4-pole
Siemens motor
7 Commissioning/shutdown
66 of 162
PumpDrive
