10. Other information - Cooling
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– WTS-300-E - V4.1 - 20.01.2022
Page 141
10.6 Tanks and silos with multiple cooling stages (cooling step control)
The WTS-300 supports silos with up to three cooling stages. 5 different methods are
possible to control the second and third cooling steps.
Applicable for all methods:
In the parameters [A1..A20] the connected cooling levels and compressors have to
be assigned to the corresponding output relays.
1. Cooling steps are switched on with a time delay
Set parameter [P73] to method 1.
Set parameter [P74] (time delay 2nd cooling step - from end of cooling start delay)
to the desired delay time.
Set parameter [P75] (time delay 3rd cooling step - from activation of 2nd cooling
step) to the desired delay time.
Set the desired time delay of the cooling steps to each other in parameter [P78]
(effective after the first switch-off of the cooling steps).
2. Cooling steps are switched on by level switch
(silo only)
Precondition: installed level switch per cooling step
Set parameter [P73] to method 2.
Assign the level switches to one of the digital inputs [A21... A33]. (Setting 16 or 17
for "Level switch 1 or 2").
Set the desired time delay of the cooling steps to each other in parameter [P78]
(effective after the first switching off of the cooling steps).
3. Cooling steps are switched on depending on the filling quantity
(silo only)
Precondition: installed analogue
pressure sensor "filling level”
Set the level switch as described in section 10.5.
Set parameter [P73] to method 3.
Set the filling quantity in [P76] in litres to switch on cooling level 2.
Set the filling quantity in [P77] in litres to switch on cooling level 3.
Set the desired time delay of the cooling steps to each other in parameter [P78]
(effective after the first switching off of the cooling steps).
4. Cooling steps are switched on simultaneously (parallel operation)
All cooling steps are simultaneously switched on to each other with a short time
delay [P78]. Parallel operation is already active during the cooling start delay.
Set parameter [P73] to method 4.
Set the desired time delay of the cooling steps to each other in parameter [P78].
(Immediately effective)
5. As method 2 - with additional timeout*.
Precondition: installed level switch per cooling step
Set parameter [P73] to method 5.
Assign the level switches to one of the digital inputs [A21... A33]. (Setting 16 or 17
for "Level switch 1 or 2").
Set the desired timeout times* for cooling level 1 + 2 in parameter [P74 + P75].
Set the desired time delay of the cooling steps to each other in parameter [P78].
(Effective after the first switching off of the cooling steps).
* Timeouts:
If the set levels are not
achieved within the
timeouts, the relevant
cooling steps are still
switched on.
Side evaporator 2
Side evaporator 1
Floor evaporator
