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Translation from original instructions
7.3 System testing
Specific logics have been developed according to which the controller manages the hydraulic systems connected to the
unit.
The management logics are intended to increase system efficiency and save energy for water circulation at the same time.
With the help of these logics, the circulating water fulfils the demands of the system, without exceeding the design flow rate
limits and without jeopardising correct operation of the cooling unit.
Each management logic refers to a specific system type and it requires some arrangements both at the time of installation
and at start-up.
7.3.1 Flowzer VP
The “VP” function requires that the pump operates at constant speed, which is made possible by the inverter fitted to control
it.
The pump speed must be set up to achieve the system rated flow.
This function is useful when the flow rate of the pump aboard the unit is higher than the rated flow. The result of flow rate
reduction is energy consumption saving.
The reduction of the pump speed is set as a percentage value of the nominal speed.
When the pump speed is changed manually, attention must be paid to avoid reducing the water flow rate to
below the minimum value allowed for the unit.
Two pump speed setpoints are provided for free cooling units: one for cases when free cooling is disabled
and one for cases when free cooling is enabled in order to make up for head losses experienced in the
water coil.
For free cooling units with decoupling exchanger (FC/NG) where the head losses do not change, only one
value is set.
Do not set the water flow rate outside the operating limits allowed in the Technical Catalogue.
The speed of the pump in units featuring an advanced controller is set up using the controller display. The speed of the
pump in units featuring a base controller is set up using the inverter display.
7.3.1.1
Adjustment of pump speed
To set the desired water flow rate as the operating set value, manually check the percentage pump speed to which it cor
-
responds.
Then manually edit the percentage speed of the pump until the water flow rate required for operation is achieved and finally
store this value as the operating set.
The necessary steps are described below:
- go to the main screen and press the arrow right button;
-
click the arrow down button to select the “Flowzer” function and then press “Enter” to confirm;
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double click the “two arrows down” button and gain access to the screen where parameters are set up manually;
-
press the “arrow” buttons to move and then “ENTER” to confirm your selection in order to enable manual operation and
edit the pump speed percentage value until the required water flow rate is achieved;
-
press the “two arrows up” button to go back to the previous screen: press the “arrow” buttons and then “ENTER” to
confirm in order to set the percentage value that has been manually stored in the operating set.
The controller in units featuring a heat pump offers the possibility to set a percentage speed for operation in cooling mode
and one percentage speed for operation in heating mode.
If two sets are required, the same percentage value must be set in both.
