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13.4 Series flow-rate modulation
(dipswitch 8 On)
Atomised water flow-rate can be modulated as a percentage of rated
production, from 10% to 100%. Each humidifier is managed with two
transducer lines (front and rear) and each line generates 50% of total
production. If humidity demand from the external signal (when using the
optional card and proportional control) and parameter P0 are both 100%,
both transducer lines will be activated. For lower demand, production
will be split between the two pairs of transducers as follows:
•
51% - 99%: one pair of transducers is always activated to generate 50%
of required production, while the other pair modulates - as described
in the previous paragraph - to generate the remaining percentage
of production. (e.g. 75% demand: one pair of transducers is always
activated, the other modulates at 50%, as shown in Fig. 13.d)
•
10% - 50%: one pair of transducers is always off, the other modulates
- as described in the previous paragraph - to generate the required
percentage of production. (e.g. 25% demand: one pair of transducers is
always off, the other modulates at 50%, as shown in Fig. 13.d)
Distribution of production between the two pairs of transducers is rotated
every hour of operation, to avoid uneven ageing of the transducers.
13.5 Automatic insufficient supply water
management
The humidifier detects if the water supply is interrupted (or insufficient)
by monitoring the status of the level sensor after opening the fill solenoid
valve. If the sensor is not activated within the time set for parameter bA
(default 15 minutes), humidification is interrupted, the drain is activated
and humidifer waits a set number of minutes (parameter AA, default
10), during which the display shows “Rty” (Retry), before attempting to
fill with water again.. If this attempt succeeds, production will resume,
otherwise the appliance waits a further AA minutes. The process is
repeated until the water supply returns, as measured by the sensor.
For the first two attempts, no alarm is generated, while if on the third
attempt the procedure is not successful, alarm EF is generated, which is
reset automatically when the humidifier verifies that the water supply is
available again.
13.6 Automatic control of atomised water
production
The humidifier monitors the water level inside the tank during production
of atomised water. If the level does not fall, it means one of the following
faults may have occurred:
•
Malfunction of the piezoelectric transducers
•
Leaky fill solenoid valve
•
Fan malfunction
If after the set time for variable A8 (in minutes, default 30) the water level
does not fall below the low level threshold, atomised water production
stops and humidifier waits a set number of minutes (parameter AA,
default 10), during which the display shows “Rty” (Retry), before
attempting to resume production. If the situation is repeated, alarm EP is
activated, which shuts down the unit.
If after a percentage of A8, set by parameter Ab (default 70%) the water is
above the high level threshold, atomised water production stops, warning
EL is generated and the appliance waits AA minutes (default 10), during
which the display shows “Rty” (Retry), before attempting to resume
production. The warning signal EL is reset at the end of a production
cycle that is completed correctly.
13.7 Automatic control of leaking drain
solenoid valve and fill solenoid valve
flow-rate
Parameter A9 sets a minimum production time (default 1 minute); if
the production cycle lasts less than this time, it may mean that the drain
solenoid valve is leaking or that the fill solenoid valve flow-rate is too low.
In this case, the controller carries out the following operations:
1.
At the end of the first cycle that ends after a time less than A9, the
water refill time is increased (50% higher than parameter bb) and
the reduced power supply voltage to the drain solenoid valve is
deactivated with the objective of increasing tightness.
2.
At the end of the second cycle that ends after a time less than A9, the
water refill time is increased further (100% higher than parameter
bb) and a chattering* cycle is activated on the drain solenoid valve,
performed during the first automatic wash cycle.
3.
At the end of the third cycle that ends after a time less than A9, the
water refill time is increased further (150% higher than parameter
bb) and a washing cycle is performed, during which chattering* is
applied, as enabled in the previous step. Warning Ed is also generated.
4.
After the final step, a new production cycle will be activated. If the
problem persists, the controller will restart the procedure from the
first step, until completing a cycle in the expected time. In this case,
any warnings will be reset.
*Chattering: a sequence in which the drain solenoid valve is opened/
closed in rapid succession, with the aim of removing any residues (scale,
dust, etc.) that prevent it from closing correctly.
13.8 Automatic protection of the
piezoelectric transducers
The piezoelectric transducers will, by nature, be rapidly damaged
and eventually break if operated without water. To prevent this from
happening, the control board makes sure, via the level sensor, that even
in the event of anomalies the transducers are never activated when no
water is present. When starting with the tank empty, the transducers are
only activated when the low level is measured. When refilling during
operation, i.e. after the water level has fallen below the minimum as a
result of consumption due to atomisation, with consequent activation of
the fill solenoid valve, if the level does not rise in the minimum time
(AC),
the transducers are switched off , while the filling cycle continues until
the level has been replenished or bA minutes have elapsed since the water
fill cycle started. If the level is replenished correctly, the piezoelectric
transducers are immediately restarted.
