DAB MCE-30/P, Instruction For Installation And Maintenance

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ENGLISH
77
4. MULTI INVERTER SYSTEM
4.1 Introduction to multi inverter systems
A multi inverter system comprises a pump set made up of a series of pumps with delivery outlets all
conveying to a single manifold. Each pump of the set is connected to its own inverter and the various
inverters communicate via a special connection (Link).
The maximum number of pump-inverter elements possible in a group is 8.
A multi inverter system is mainly used to:

Increase the hydraulic performance with respect to a single inverter

Ensure operation continuity in the event of a fault on a pump or inverter

Partition maximum power
4.2 Setting up a multi inverter system
The pumps and motors that make up the system must share the same technical specifications. The
hydraulic system must be as symmetric as possible in order to achieve a hydraulic load evenly distributed on
all the pumps.
The pumps must all be connected to a single delivery manifold and the flow sensor must be placed on the
outlet of the latter to read the flow to the entire pump set. In the case of using multiple flow sensors, these
must be installed on the delivery of each pump.
The pressure sensor must be connected to the outlet manifold. If more than one pressure sensor is used,
these must also be installed on the manifold or in any event on a pipeline that is connected to it.
NOTE:
If multiple pressure sensors are read, take care that the pipeline on which they are mounted is not
equipped with non-return valves between one sensor and the next; otherwise different pressure
values may be read which lead to false average readings and incorrect settings.
For optimal operation of the pressure set, the following must be the same for each inverter-pump pair:

type of pump and motor

hydraulic connections

rated frequency

minimum frequency

maximum frequency

the shutdown frequency without flow sensor
4.2.1 Communication cable (Link)
The inverters communicate with each other and propagate flow and pressure signals through the special
connection cable. The cable is supplied in the 2 m standard version however longer cables are supplied
upon request.
The cable can be connected to any one of the two connectors marked “Link”, see Figure 5.
WARNING
:
only use cables supplied with the inverter or which are considered as inverter accessories (it is
not a standard cable available on the market).
4.2.2 Sensors
The sensors to be connected are the same versions used in stand-alone versions, i.e. pressure sensor and
flow sensor. Operation without a flow sensor is admitted on multi inverter systems.