Donaldson standard, Manual

Page: 11 / 36

6.1 Basic functions / operating
modes
Condensate flows through the inlet of the con-
densate drain and is accumulated in the col-
lection area. System pressure keeps the
diaphragm closed to the underside. When the
moisture sensor detects liquid, the pressure is
released from the diaphragm. The diaphragm
then opens and the system pressure forces
the condensate out. The diaphragm is closed
before air can escape.
The operating conditions are displayed by two
(2) LEDs.
The software controls the drain in one of the
following three ways:
6.2 Level-controlled operation
This is the normal operation. The power LED
is constantly illuminated green.
If the sensor signals "wet", the solenoid valve
will be activated.
6.3 Overload operation
Occurs most frequently on fridge-dryers on
start-up after a shut down. A splash like accu-
mulation of condensate occurs that cannot be
discharged through a single drain discharge
impulse. If the sensor still signals "wet" after
drain off, the solenoid valve will open again
until clear. If this "splash operation" is activat-
ed continuously for ten (10) minutes, the con-
trol goes into alarm mode. Once the sensor
signals "dry", the control cancels the alarm
mode.
6.4 Alarm operation
The alarm operation is activated, if the sensor
is defective.
Detection of a malfunction:
Exceeding the maximum splash time (see
overload operation),
Disrupted sensor cable respectively, no
contact to the inner electrode,
Electronic failure.
Action:
The potential free contact (alarm contact) will
be opened; the service LED flashes red. The
alarm operation will be deactivated once the
sensor signals "dry" again.
The alarm outlet will be activated at operation
with a defective or factory new (unpro-
grammed) EPROM. The service LED will flash
red and the drain will operate in alarm mode.
For hygienic reasons, the condensate must
not be kept in the drain for excess periods of
time. Therefore, the drain opens on a time-
controlled basis.
6.5 Service operation / Service
reset
Upon reaching the programmed service time
(or maximum number of drain cycles), the ser-
vice LED will constantly illuminate yellow. This
is to remind the service personnel of the nec-
essary maintenance (exchange of consum-
able parts). After a one week warning time,
the yellow service LED will switch to a flashing
yellow in order to point out the urgency of the
maintenance. Even though the yellow service
LED is on, the device will continue to operate
normally.
If an additional alarm exists, the service LED
will flash alternate red/yellow, whether or not
the warning time has already elapsed.
The reading of the cycles counter is stored
one (1) time per hour.
Service reset
:
After applying power to the unit, the test but-
ton should be pressed for 20 seconds to
acknowledge service.
The yellow LED turns off, the readings of the
service counter and the cycles counter will be
set to the actual readings of the last mainte-
nance. This function is only available if the
drain already reports service.
6 Operation
US
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