DAB esybox mini 3 Installations- Und Wartungsanleitungen Seite 45

user interface panel is composed of a display and a keyboard and its function is to set the system, query its status and communicate any alarms.
The door closed by 2 screws gives access to a special maintenance compartment: cleaning of the check valve and resetting of the tank preload
pressure.
The system can be installed in 2 different configurations: horizontal (Fig.4) or vertical (Fig.5).
1.2 Description of the Integrated Inverter
The electronic control integrated in the system is of the type with inverter and it makes use of flow, pressure and temperature sensors, also
integrated in the system.
By means of these sensors the system switches on and off automatically when a faucet (or otherwise) is opened or closed, and it is able to detect
conditions of malfunction, to prevent and indicate them. The Inverter control ensures different functions, the most important of which, for pumping
systems, are the maintaining of a constant pressure value in delivery and energy saving.
• The inverter is able to keep the pressure of a hydraulic circuit constant by varying the rotation speed of the electropump. In operation without
an inverter the electropump is unable to modulate and, when there is an increase of the request for flow, the pressure necessarily decreases,
or vice versa; this means the pressures are too high at low flow rates or too low when there is an increased request for flow.
• By varying the rotation speed according to the instantaneous request of the utility, the inverter limits the power supplied to the electropump to
the minimum necessary to ensure that the request is satisfied. Instead, operation without an inverter forces the electropump to run always
and only at maximum power.
For the configuration of the parameters see chapters 4-5.
1.3 Integrated Expansion Vessel
The system is complete with an integrated expansion vessel with a total capacity of 1 litre. The main functions of the expansion vessel are:
• to make the system elastic so as to protect it against water hammer;
• to ensure a water reserve which, in the case of small leaks, maintains the pressure in the system for a longer time and spreads out needless
restarts of the system which otherwise would be continuous;
• to ensure adequate water pressure when a faucet (or other device) is opened for the seconds that the system takes to switch on and reach
the correct rotation speed.
It is not a function of the integrated expansion vessel to ensure a water reserve such as to reduce interventions of the system (requests from the
utility, not from a leak in the system). It is possible to add an expansion vessel with the capacity you prefer to the system, connecting it to a point
on the delivery system (not a suction point!). In the case of horizontal installation it is possible to connect to the unused delivery outlet. When
choosing the tank, consider that the quantity of water released will also depend on the parameters SP and RP that can be set on the system
(Section 4-5).
The expansion vessel is preloaded with pressurised air through the valve accessible from the special maintenance compartment (Fig.1, Face F).
The preload value with which the expansion vessel is supplied by the manufacturer is in agreement with the parameters SP and RP set as default,
these values being based on the following equation:
Pair = SP – RP – 0.7 bar
So, by the manufacturer:
If different values are set for the parameters SP and/or RP, regulate the valve of the expansion vessel releasing or letting in air until the above
equation is satisfied again (e.g.: SP=2.0 bar / 29 psi; RP=0.3 bar / 4.3 psi; release air from the expansion vessel until a pressure of 1.0 bar / 14.5
psi is reached on the valve).
Failure to respect the above equation may lead to malfunctions of the system or to premature breakage of the diaphragm inside
the expansion vessel.
Considering the expansion vessel capacity of only 1 litre, any operation to check the air pressure must be performed by connecting
the pressure gauge very rapidly: on small volumes the loss of even a limited quantity of air can cause an appreciable drop in
pressure. The quality of the expansion vessel ensures the maintenance of the set air pressure value, proceed to check it only at
calibration or if you are sure of a malfunction.
Figure 4
Where:
- Pair = air pressure value in bar
- SP = Set Point (chapter 5.3.1) in bar
- RP = Reduction of pressure to restart (chapter 5.5.1) in bar
Pair = 3 – 0.3 – 0.7 = 2.0 bar / 43.5 – 4.3 – 10.1 = 29 psi
ENGLISH
42
Figure 5