Wilo Stratos 1.25x3-20 Notice De Montage Et De Mise En Service page 14

English
• Pump kick: Any pumps switched off via the menu (ON/OFF), a bus
communication, the infrared interface, the Ext.Off control input or 0-10V start
running for a short time every 24 hours to prevent blockages in the event of long
periods of standstill. The mains voltage must not be interrupted for this
function.
If the mains is intended to be switched off for a long period of time, the pump
kick must be assumed by the heating/boiler control system by briefly switching
on the mains voltage. For this purpose, the pump must be switched on by the
control system prior to the interruption to the mains supply (display o motor/
module symbol lit up).
Connections to the building management system (BMS)
• FC: A collective fault contact FC (potential-free closed contact) can be
connected to a control point (building management system) as standard. The
internal contact is closed if the pump is turned off, or there are no problems or
failures on the part of the control module. The faults are described in detail in
chapter 10.
• IF(Interface) modules (accessory):
Analog interfaces are available in the form of add-on IF modules for connecting
to external control system (e.g. DDC/BMS).
6.2.5 Twin-head pump operation
Twin-head pumps or two corresponding single pumps in a parallel pump
installation can be fitted with built-in double-pump management.
• Stratos IF module: Two IF modules connected via the DP (double pump)
interface are required for communication between pumps. In addition to double
pump management, the IF modules provide other interfaces for the double
pump.
This double pump management has the following functions:
• Master/Slave: Both pumps are controlled by the master. All settings are made
by the master.
• Optimum-efficiency peak-load operation: The twin-head pumps or two
corresponding single pumps can be run in a low/high flow application where if
the lead pump can not keep up with the flow demand the lag pump will operate
automatically. At partial load, the hydraulic capacity is provided by one pump
only. The second pump is switched on at optimum efficiency, when the sum of
power consumptions P
of one pump. Both pumps are then adjusted upwards simultaneously to max.
speed if necessary. In relation to the conventional peak load operation (load
controlled switch on and off) a further energy saving is reached by this mode of
operation.
• Duty/Standby mode: Each of the two pumps produces the design delivery rate.
The other pump can be used in the event of the first pump malfunctioning or
following a pump swap. Only one pump operates at a time.
• In the event that one pump experiences a failure/problem, the other will run as
a single pump in standard mode as instructed by the master.
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of both pumps is less than the power consumptions P
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Subject to technical alterations! WILO SE 02/2011
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