AHT 20-350, User Maintenance Manual

Page: 18 / 44

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5.14 DMC14 ELECTRONIC INSTRUMENT (AIR DRYER CONTROLLER)
set
Button - access the set-up.
esc
Button - Exit programming / decrease value.
Button - Value increment.
LED
- Dryer in alarm status.
●
°C
LED - Display the set temperature scale (°C).
●
°F
LED - Display the set temperature scale (°F).
DMC 14
°C
°F
esc set
DISPLAY
P
Q
S
0
0
0
6
●
LED
- Not used
Through the digital thermometer with an alphanumerical display, the DMC14 controller shows the DewPoint
detected by the probe in the evaporator.
The LED shows any alarm condition, it can happen when :
- pressure DewPoint is too high;
- pressure DewPoint is too low;
- the probe is faulty.
If the probe is faulty, the instrument also shows “PF” message (Probe Failure), and alarm activation is immediate. In
case of “DewPoint too low” condition (ASL parameter, that is fix and equal to 28.5°F or -2°C), the alarm signal is
delayed of a fix time (AdL parameter) equal to 30 sec, while for “DewPoint too high” condition the value (ASH
parameter) is set by the user and the signal is activated with AdH delay time, that can be also set up by the operator
(the instrument is already adjusted during final test of the dryer, please see following values). When DewPoint
returns into operating temperature (set range), the alarm condition is deactivated.
DMC14 allows also remote annunciation of the alarm condition of the dryer; this through a volt free contact on
terminals 8 & 9 - please also see electric drawings into the attachments (max 250V 1A, min 5VDC 10mA)
- with dryer off or in alarm conditions contact is open
- with dryer on and correct operating DewPoint, contact is closed.
OPERATION - After dryer starting, the electronic controller displays current operating DewPoint : it shows
the measured temperature in Celsius degrees (
●
°C) with a 0.5°C resolution, or in Fahrenheit degrees (
●
°F) with a 1°F resolution.
SET-UP (PROGRAMMING)
To access the set-up, keep pressed simultaneously both
set
and button for at least 5 seconds. In
this way programming operation will be activated and the controller display shows the first parameter
that can be set (Ton). After that, by pressing
set
buttom the display shows the value set for that parameter.
If the value is correct press
set
button to conferm it and to give access on following parameters. To
change the value of selected parameter, must be used
esc
and button, respectively to decrease or
increase the value. All parameters that can be modified are indicated in following table :
Display Description Value range Set value Equal to
Ton Not used 01 … 20 02 2 sec
ToF Not used 01 … 20 01 1 min
ASH Alarm threshold for a high DewPoint . 0.0 … 68.0 60 60°F
AdH ASH alarm time before signal 00 … 20 20 20 min
SCL Temperature scale °C … °F °F °
Fahrenheit
Fixed parameters :
ASL (low DewPoint alarm) = -2°C or 28.5°F AdL (signal delay) = 30 sec
It is possibile to exit from set-up conditon in any moment, by pressing simultaneously both
esc
and button.
If any operations are not made during 30 seconds, the controller exits automatically from programming operation.