Aht 601 (°C) And Aht 701 (°F) Electronic Temperature Control - AHT ATHEN 175 Manual Del Usuario

AHT Cooling Systems GmbH
8.3 AHT 601 (°C) and AHT 701 (°F)
electronic temperature control
The AHT 601/701 Electronic Temperature Controller is
designed for single loop and feedback control of AHT
refrigeration and freezer units. The controller can be used
for stand-alone operation or for units installed in blocks. If
the units are installed in blocks, they must be connected by
bus lines. Instructions on wiring and allocating addresses
can be found under 'Selecting bus addresses'.
Before starting up the cabinet, carry out another check of
all cable connections and the power supply to make sure
they are correct and make good contact.
Operation
The temperature is shown by red LEDs in a 7-segment
display, using three characters. The controls consist of four
buttons which are arranged as shown below:
Manual defrost/set button
Standby button
Illustration of AHT 601 (°C); AHT 701 identical in appearance
+ button ... This button is used to select the approved
nominal values, assign addresses and select parameter
levels.
- button... This button is also used to select the approved
nominal values, assign addresses and select parameter
levels.
MAN. DEFROST / SET button ... For changing the nominal
value.
STANDBY button ... This button switches the feedback
control function on and off. Only the AHT 601/701 controller is
switched to standby.
General note about using buttons:
Buttons must be held down for more than 0.5
seconds to prompt a response
If a button is not pressed for 10 seconds, the display
will revert back to the 'actual' value
Once a value is set it is accepted immediately,
assuming that it is valid
Setting the nominal value
To select the temperature range within which the unit should
operate, use the following parameters.
button
Plus
Minus button
but display in °F
Parameter Function
A1 Deep freezing (required value 1)
A2 Deep freezing (required value 2)
A3 Meat refrigeration
A4 Plus cooling
A5 Free parameter
(can be set by the customer)
Setting range from -30°C (-22°F) to +15°C (+59°F)
There is no need to set a temperature, just a control range:
A1, A2, A3, A4 or A5.
The various control ranges can be blocked or approved
depending on the customer's requirements.
When setting the nominal value, you can only select from
those control ranges that have been approved.
Unless the customer has specified otherwise, the following
parameters are approved:
Freezer unit: A1
Meat unit: A3
Convertible unit: A1 and A3
Selecting the approved nominal temperature:
Controllers are supplied with the appropriate approved
nominal values depending on the cabinet type. You can select
a different nominal value as follows: If you press the "Standby
/ Reset" button for at least 1 second the unit will switch to
standby mode. The display shows: "- - -". If you press the
"Standby / Reset" button once more the unit will switch on
again and the unit's internal temperature will be displayed.
This procedure may take a few seconds.
1) Press and hold down the + or – button for at least 1s.
2) STP will appear on the display (for approx. 0.5s),
alternating with the current nominal value, e.g. A1 (for 2s).
3)
If you now press the + or – button, you can select the
next approved nominal value. You must make a selection
within 10 seconds, otherwise the display will automatically
revert to the actual value.
WARNING for (U) series: If you switch from A1 to A3 or
from A3 to A1, the unit's nominal temperature will change
either from –18°C to +1°C or from +1°C to -18°C!
4) The user is free to define the nominal value by selecting
A5. To do this, hold down the MAN. DEFROST / SET button
and then use + or – to set the nominal value to any temperature
between -30°C and +15°C. The nominal temperature setting
corresponds to the product temperature at the stacking limit
when the cabinet is full.
5) After 10s the unit will revert back to the current
temperature display / actual value. Once the unit reverts back to
the actual value, the value set by the user is adopted
immediately.
Selecting bus addresses
Controllers are supplied with the bus address 0, which
corresponds to a stand-alone unit.
When in this status (address 00), the cabinets /
controllers are not registered in the bus system.
In order to identify cabinets in the bus system, you have to
assign each one an address from 01 to 48.
19
Nominal temperature at idling
-18°C (0°F)
-20°C (-4°F)
+1°C (+33.8°F)
+4°C (+39.4°F)
-18°C (0°F)