English
16
WILO SE 11/2010
6 Description and function
6.1 Description of the unit
The main unit is a self-priming, horizontal, multi-
stage rotary pump.The pump sucks the rainwater
direct from the cistern or any storage tank for
rainwater, and drives the water to the points of
use via the pressure and flow controller.
The replenishment reservoir with a capacity of
11 litres (fig. 5, item 22) is used by the RCB
switchgear (fig. 1, item 7) to ensure that the water
supply is not interrupted even if the level of water
in the cistern is low. The pressure and flow con-
troller Ecocontrol (fig. 1, item 9) automatically
switches the pump on or off, thus protecting the
pump when there is low water.
6.2 Function of the product
Pressure and flow controller Ecocontrol
(fig. 1, item 9; fig. 4)
The pressure and flow controller Ecocontrol auto-
matically switches the pump on or off depending
on the pressure. When the unit is ready for opera-
tion and the points of view are closed, the pump is
at a standstill and the green LED light (fig. 4,
item 9a) on the front side of the pressure and flow
controller Ecocontrol lights up.
If a point of use is opened, the pressure within the
system will drop. The pump will start as soon as
the start-up pressure reaches 1.5 bar. The
orange-coloured LED light (fig. 4, item 9b) lights
up.
If the point of use is closed, the pressure increases
and the volume flow drops. If the volume flow
drops below approx. 3 l/min. the pump will switch
off automatically.
The pump will automatically switch off if the pres-
sure is too weak or there is zero flow (low water or
dry run). An error will be indicated by the red LED
light (fig. 4, item 9c).
Once the fault has been remedied, the operator
will have to keep the fault acknowledgement con-
trol button (fig. 4, item 9d) pressed down until the
pressure in the system is restored. If the pressure
cannot be restored with sufficient speed, a fault
will be indicated by the red LED display.
Replenishment reservoir (fig. 5, item 22)
A replenishment reservoir is arranged next to the
pump. It provides the system will water from the
public water supply when there is a low water level
in the cistern. The separation between the public
water supply and the installation on the rain water
side required to safeguard the potable water in the
system is ensured by means of an overflow of type
AB (fig. 5, item 19) in accordance with the
EN 1717 standard.
Water is fed from the public water supply to the
replenishment reservoir via a float valve in the
tank (fig. 5, item 18). The overflow (fig. 5, item 19)
enables defined channelling of water, in the event
of a fault in the float valve, into an overflow chan-
nel to be established onsite. A direct connection
between overflow and the connection to the
sewer must be made impossible.
When the water reserve in the cistern has fallen
below the minimum level, the float switch signal
(fig. 5, pos. 2) in the cistern activates the switch-
ing valve (fig. 5, pos. 16), switching it to operate
from the rainwater storage tank. The system is
now operated via the replenishment reservoir
using water from the public water supply. If the
water falls below the minimum level in the cistern
again, a signal from the float switch in the cistern
will trigger the switching value to return to oper-
ate from the cistern.
RCB switchgear (fig. 1, item 7)
The conversion of the float valve signal into the
switching commands for the switching valve takes
place in the RCB control device (fig. 2, and 3). The
operational state of the control device and cistern
operation is indicated by the permanent green
LED light. If the rainwater utilisation system is
supplied with water from the public water supply
(feed mode), this is indicated by a permanent
orange LED light.
Pressing the control button (combination of mul-
ticoloured LED light and button) on the RCB
switchgear switches the rainwater utilisation sys-
tem from automatic mode to manual operation
(permanent use of water from the public water
supply). Manual operation is indicated by a flash-
ing orange LED light. Pressing the control button
again deactivates manual operation once again
and the rainwater utilisation system runs in auto-
matic mode. The rainwater utilisation system will
continue to work in feed mode if the cistern is not
fed enough water.
NOTE: The switch to the cistern only works when
there is enough water in the cistern. The feed
mode will not be switched off automatically if it is
activated via the control switch. Accordingly, the
unit can be permanent switched to operation with
water from the public water system.
After an operating time of 3 weeks in cistern oper-
ation, the system will automatically switch to feed
mode operation from the replenishment reservoir
until the pump has run in this mode for 3 min-
utes.This ensures that the water in the replenish-
ment reservoir is regularly exchanged. Every time
a switch is made to feed mode operation from the
replenishment reservoir, this resets the 3-week
counter.
Summary of Contents for Wilo-RainSystem AF Comfort MC 304 EM
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