AHT Cooling Systems GmbH
on21.05.2018 21:36
Page 44
361929_0917_BA_SM_V4_06.09.2017_U_enUS_CD.docx
24-hour defrosting block:
If “---” is shown briefly on the display and then the
temperature, the 24 hour defrosting block is active.
2.) End the semi-automatic defrosting:
The device automatically reverts to normal mode.
The current temperature is shown on the display
again.
Alarm display and acknowledgment
Alarm display:
The
fault code
flashes alternately on the display with
the temperature for several minutes. Thereafter, only
the point flashes (see
→
Fig. 2.1 No. 5).
With each full hour, the fault code is shown on the
display for approx. 10 minutes.
Calling up the
fault code
in-between:
Press the
[STANDBY]
button briefly.
Depending on the fault, an
acoustic signal
can also
be issued by a built-in buzzer.
Alarm acknowledgment
:
The fault code
or
the flashing point
and the
acoustic signal
CANNOT be acknowledged.
List of fault codes:
Fault code
Meaning
Bus
Bus fault
Col
Address collision bus
F1
Sensor fault F1
F2
Sensor fault F2
F3
Sensor fault F3
dFr/F3 alternating
Defrosting system fault
Clock
Time/date fault
EE
Data backup fault
Flashing
temperature value
Excessive temperature alarm
FU1**)
Communication fault
controller/inverter
FU2**)
Overvoltage fan output of the
inverter
FU3**)
Compressor start fault
FU4**)
Compressor overvoltage
FU5**)
Inverter excessive
temperature
FU6**)
Inverter internal fault
FU7**)
Inverter supply voltage outside
the limits
** only with speed-controlled compressor (VS)
AHT electronic controller (SECOP)
There are 3 buttons available as operating elements,
which are allocated as follows:
Fig. 3: Electronic controller, operating elements and screen
displays
No.
Operating element
Function
1
Button
[+/-]
Application change (A1-A4)
Increase bus address
2
Button
[MAN.
DEFROST]
Start semi-automatic
defrosting
3
Button
[STANDBY
RESET]
Start defrosting manually
Switch the cooling function
on or off
Call up fault code (if point
flashes)
Acknowledge acoustic alarm
No. Display
Meaning
4
Illuminated red point
(next to the horn signal)
Alarm display
Switch the cooling function on and off
Switch cooling function off (start the defrosting manually):
Press the
[STANDBY RESET]
button for
minimum 3 sec. “---” is shown on the display.
Switch on the cooling function:
Press the
[STANDBY RESET]
button for
minimum 3 sec. The current temperature
appears on the display screen.
Setting the application
The following applications A1-A4 (customer-specific
approval) can be selected.
Display application set:
Press the
[+/-]
button briefly.
The currently set application is shown on the
display, e.g. “
A1
”.
If no changes are required, the display returns to the
temperature display after approx. 5 seconds.
Change application:
By pressing the
[+/-] button
several times,
you can run through all the released
applications.
Accept new entry:
The newly set application is accepted
automatically approx. 5 seconds after
pressing the button for the last time.
Assigning the bus address
Before assigning, the devices must be networked
with a corresponding bus cable. On the last device,
the bus cabling must be terminated with a terminal
4