Xylem HYDROVAR WATERCOOLED - Manual (Page 16)

16
Set Point (bar)
Pre charge pressure tank (bar)
Example:
Maximal capacity of the pump = 70 Liter per minute
Minimum volume of the pressure tank = 70x0.10 = 7 Liter
A certain pre-charge pressure has to be in the pressure tank when there is no water in the tank, determined by the
required pressure or the start value when activated.
Special application: Constant pressure control with external release contact:
For irrigation systems the Hydrovar-Watercooled can be mounted without check valve and pressure tank, if the
Hydrovar-Watercooled will be activated with an external release contact.
The Hydrovar-Watercooled keeps the system pressure constant, while the external contact is closed (irrigation is
on) and is switched off by the external contact when the irrigation system is not in use.
Notice:
To protect the pump against air inlet from the suction side or working below an allowed incoming pressure level, it
is necessary to connect an external protection unit to the release contact terminals of the unit. The Hydrovar-
Watercooled
shuts off when the contact will be opened and turns on if the contact will be closed.
When there is an application of sucking out water from a well or a tank there has to be used a level probe or a float
switch as the low water protection.
For booster stations a pressure switch has to be mounted for low water protection. When the pressure switch
opens the contact of the Hydrovar-Watercooled will detect low water and the pump will be stopped.
For protection against contamination inside the cooling pipe of the Hydrovar-Watercooled (e.g. at pumping of
service or rain water) we recommend a filter before the unit.
Dimensions in mm (drawings not in scale)