3. START UP
Ensure that the dryer is by
−
passed, or there is no load on the cooler.
Switch on the main electrical isolation switch (if present). The control panel will show the message OFF, indicating that the
line and control voltages are available.
Start sequence
The dryer will initially start by pressing the local ON/OFF button for 1 second. The start sequence will progress only if there
are no active alarms. The compressor motor will start AFTER 120 SECONDS. The fan motor will start simultaneously with
the compressor for D300-360IN models, after 30 seconds for smaller models.
Stop sequence
The dryer can be stopped locally from the control panel. After having pressed the ON/OFF switch for 1 second, the
compressor and the fan motor keep on running for further 10 seconds in order to re-balance the internal pressures. The
dryer can be also stopped due to an alarm or energy saving condition (ESA or ES2). Any alarm will de
−
energize the
compressor, fan motor can still running, it depends on the type of alarm (see Display indications chapter). If the shutdown is
due to an alarm, a message will blink on display indicating the reason for the shutdown. Energy saving condition (ESA or
ES2) occurs when the dew point stands below the set value for a long time in order to save energy and avoid heat
exchanger freezing. This situation can happen when ambient temperature is low and there is no compressed air load.
Variable speed fan control
A patented microprocessor allows to adjust dryer’s cooling capacity by changing the fan motor speed. If the dew point is
greater than the set value, the fan speed is increased, if the dew point is smaller than the set value, the fan velocity is
decreased. The range can be from 0 to 100% and the higher is the fan speed, the faster the fan LED blinks, you can read
the exact value by pressing the UP button. If the velocity is 100% you will read FL (Full Load). Under load standard
condition the fan speed is usually at 100%, if there is no load the fan velocity can oscillate between 0 and 20%.
In models D300-360IN, in order to adjust the greater dryer’s cooling capacity, a hot gas by-pass valve cooperates with the
variable speed system.
3.1 CONTROL PANEL
The dryers are provided with an electronic control system. All adjustments and resets can be performed by means of the
digital panel located on the front of the dryer.
The control panel is composed of 5 keys (ON/OFF, TEST, SET, DOWN and UP) and a 3 digit display, with three
signalling LEDs indicated by icons (PIC 1)
PIC. 1
DISPLAY VISUALIZATION
AND SIGNALLING LEDS
DISPLAY
DESCRIPTION
the unit is ON with low load
the unit is ON with normal load
the unit is ON with normal-high load
the unit is ON with high load
LED
STATUS
DESCRIPTION
ON
Compressor energized
Blinking
Programming mode activated
ON
Condensate drain energized
ON
Speed of the fan = 100%
Blinking
Speed of the fan < 100%
OFF
Fan not running
Cod. 710.0138.39.00 Rev1A – 05.2008
5 - 28
Summary of Contents for D108IN
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