Swegon BlueBox Zeta Rev Series Installation, Use And Maintenance Manual page 60

- Vmin = minimum water volume in the system/plant
- UL = limit of the supply.
If the operating logic of the secondary circuit includes stopping of the water flow rate, the capacity of the buffer tank must
be sized against the min. volume of water required for unit operation.
If user points with 3-way valves are installed in the system and water is circulated to the secondary circuit, the capacity of
the buffer tank can be reduced.
To this purpose, the 3-way valves should be fitted on the furthest user points.
The bypass pipe must be of the same diameter as the connections of the unit.
7.3.2.3 Setting the operating setpoint difference
The units are shipped from the factory with a setpoint difference value of 5°C.
The procedure below explains how to edit the factory value.
- 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;
- Press the "SET" button and access the screen where the setpoint difference value is set up.
- Press "ENTER" to enable the edit window.
- Use the "arrow" buttons to set the new value and press "ENTER" to confirm.
Check that the flow rate through the heat exchanger in the unit, including without thermal load, is within the
operating limits admitted in the technical catalogue.
7.3.2.4 System type 3
The pump in the unit is also used for circulating water in the system.
A hydraulic circuit breaker controlled by a bypass valve ensures water circulation also in cases when there is no load.
As the load is reduced, the water flow rate in the system is reduced and so is the pump speed.
If the load demand is such as to excessively reduce the water flow rate in the unit, the bypass valve is opened to make up
for any missing water.
The connections of the servo control in the bypass valve have to be implemented as shown in the wiring diagram.
A sample diagram is shown below.
A2
UL
60
Translation from original instructions
BT2
BP41
ΔPex
BT1
VP
A040
Y2V
Vmin.
Y2V Y2V
We reserve the right to make changes without any prior notice.
Y3V