5
Te
chnical
suppor
t
—
+7
4
95
7
34
-9
1-
97
EN
there are two screwed connecting fittings with 1» external
thread (3) and two cable glands (4). On upper cover there is
signal LED for the device mode indication (5).
Flow sensor (FS), dual-threshold pressure sensor (PS) and
electronic circuit board with microcontroller which sets
the device operation program are installed inside housing.
FS consists of turbine rotating upon an axis by water flow,
and sealed contact. In turbine vanes, there are two magnets
installed symmetrically.
The device operating principle is that the flow sensor
turbine starts to rotate when water flow is passing through
it at a rate higher than 2 l/min. The sealed contact, when
approaching magnets in turbine vanes, receives pulses
and delivers them to microcontroller. The microcontroller
processes this information, and power relay turns the pump
on. At this time the pump continuously delivers water
producing the system pressure corresponding to pressure
thresholds Pmin (cut-in pressure) and Pmax (cut-off pressure)
preset by sensor.
If the pump, for some reason, cannot produce the system
pressure Рmax, then it is switched off with 30-second delay
when water flow stops or its rate drops to 2 l/min and is
automatically switched on when water flow rate is more
than 2 l/min but not earlier than in 2 seconds after the pump
switching off. In this case the system pressure is determined
by the pump parameters, pressure tank capacity and
connection diagram thereof.
In the absence of water flow, the control unit automatically
switches the pump off providing protection against dry-
running and other emergency situations.
