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8.5.4 Functional check run
Functional check run
A Check Run can be activated for the pump set (parameter 2-4-4-1), so the pump set starts
up regularly if it has not been operated for a defined period of time. The Function can be
triggered by different sources (parameter 2-4-4-2). When the function is configured based on
idle time and a pump set has not been operated for a configurable Standstill Time
(parameter 2-4-4-4), the pump set will be started up and operated for a defined Duration
(parameter 2-4-4-3). When a Time Stamp for Activation has been set (parameters 2-4-4-5
and 2-4-4-6) and the function has been configured for a time of day, all pump sets that are
not in operation and have got the same time stamp are started up for a check run, one after
the other. When the function is configured for a Triggered Check Run, the check run takes
place when the digital input level is high. For this purpose, the check run must be assigned a
digital input (one of parameters 1-3-3-1 to 1-3-3-18).
8.6 System protection
8.6.1 Dry running protection
Dry running
protection
To prevent dry running of the pump sets the control unit monitors the suction side of the
pressure booster system for lack of water. The availability of water can be monitored with
different devices.
Lack of water has to be detected for a defined period of time (Delay Time for System Stop)
(parameter 2-5-1-1-2) before the message is triggered. If a lack of water is detected, all
pumps are stopped automatically with a Dry Running Protection Stop Delay (parameter
2-5-1-1-5) between the stops of the individual pump sets.
If no lack of water is detected any more, a defined Delay Time Reset (parameter 2-5-1-1-3)
has to pass before the lack-of-water message can be reset.
The suction-side pressure can be monitored by a pressure sensor. For calibrating the
sensor range the pressure Value at 4 mA (parameter 1-3-7-1-1-1) and the pressure Value at
20 mA (parameter 1-3-7-1-1-2) can be used. The
suction-side Pressure sensor
has to be
selected as the Source (parameter 2-5-1-1-1). Further to be set are the Minimum Suction-
side Pressure for System Stop (parameter 2-5-1-3-1) before a dry running condition is
detected, and the Minimum Suction-side Pressure for Reset (parameter 2-5-1-3-2) when the
lack of water condition is no longer present. When using a pressure switch,
Pressure switch
has to be selected as the Source (parameter 2-5-1-1-1). Dry running protection is then
effected in accordance with the corresponding digital input for the pressure switch
(parameters 1-3-3-1 to 1-3-3-18). A dry running event is detected when the input signal level
is low. A float switch can also be used, provided an inlet tank is installed upstream of the
pressure booster system. In this case,
Float switch
has to be selected (parameter 2-5-1-1-1)
and the float switch has to be assigned as digital input (parameters 1-3-3-1 to 1-3-3-18). A
dry running event is detected when the input signal level is low. For pressure booster
systems with an upstream inlet tank whose fill is also monitored by the control unit, a
pressure sensor installed at the tank that measures the tank fill level can also be used for
dry running protection. In this case,
Pressure sensor at tank
has to be selected as the
Source (parameter 2-5-1-1-1). The Low-water Level (parameter 2-7-1-2-7) and the Low-
water Reset Level (parameter 2-7-1-2-8) of the tank correspond with the general lack-of-
water levels. An Additional Source can also be set (parameter 2-5-1-2-1). In this case, two
sources that are independent of each other are used for monitoring the lack of water.
Different types of monitoring can be used in this way. The Delay Time for System Stop and
Delay Time Reset can be set separately for each monitoring source (parameter 2-5-1-2-2
and parameter 2-5-1-2-3). In particular, a Maximum Number of Dry Running Protection
Events per Hour can be configured (parameter 2-5-1-1-4) to monitor the number of lack of
water events that have occurred. If this number is exceeded, an information message is
output.
8.6.2 Response to pressure sensor failure
Pressure sensor
failure
In the event of a pressure sensor failure on the discharge side, a pump set response can be
selected to ensure a specific water supply. Pump response to pressure sensor failure is
selected separately for pump sets in mains operation (parameter 2-4-1-5) and pump sets
