Carel Hecu handleiding
Handleiding
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Hecu +0300023EN rel. 1.2 - 14.12.2021
Minimum pressure di erential for lubrication
The minimum pressure diff erential threshold for correct lubrication is
related to the type of BLDC compressor and cannot be modifi ed. The low
pressure diff erential alarm is generated when the diff erence between
condensing pressure and evaporation pressure (DeltaP) remains below
the limit defi ned by the compressor manufacturer for a set time, and
consequently excellent lubrication is not guaranteed. The alarm stops
the compressor and is reset automatically. The alarm is not active during
defrosting.
The corresponding parameters are in loop Compressors Æ Advanced
Æ screen Cag55.
DSH control
Hecu controls superheat on the compressor discharge line at the same
time as superheat on the suction line.
If suction superheat is less than 0K and discharge superheat is less than
10K, a countdown starts to set off the corresponding alarm (DSH Low
Liquid Flowback).
The alarm activation delay can be set on screen Cae41 and can be
diff erentiated for diff erent stages of operation: compressor start-up,
steady operation, defrost/washing active.
Timers
Time management includes a minimum On time, a minimum Off time
and a minimum time between two consecutive starts.
These parameters can be modifi ed under Compressors Æ Confi guration
Æ screen Caf35:
The logic is described in the following graph:
min ON
time
min OFF
time
min time to start
same compressor
10s
time
ON
Comp
OFF
Fig. 6.e
6.3 Compressor control
Control can be proportional or proportional + integral (P, P+I). The
corresponding parameters are in loop Compressors Æ Control Æ
screen Cab14.
The set point is in the centre of the band. Proportional control is illustrated
in the following fi gure:
Regulation request
100%
Setpoint
Regulation
probe value
Differenziale
Fig. 6.f
With proportional + integral control, the integral time is summed to
the eff ect of proportional control, giving a null control error in steady
operation. This type of control is illustrated in the following fi gure:
Regulation
variable
P+I
P
Setpoint
time
Fig. 6.g
The integral action depends on time and the deviation from the set point.
The integral time represents how fast integral control is implemented:
• Low values bring fast actions yet more instability
• High values bring slower actions and more stability
The values should not be set too low, to avoid system instability.
Two types of control can be set, in loop
Compressors Æ Control Æ screen Cab01
• Fixed set point
• Floating set point
Floating set point
This software function is available by exploiting serial communication
with the evaporators. Serial communication allows information to be
exchanged in real time between the main Hecu controller and the
connected MPXPRO or ULTRACELLA devices.
Notice: the controllers installed on the evaporators implement the
smooth lines function (see MPX PRO manual +0300055 or ULTRACELLA
+0300083). This function signifi cantly reduces the number of ON-OFF
cycles in traditional control by modulating the evaporator temperature
using an electronic expansion valve and adapting the superheat set point
using appropriate PI control based on the eff ective control temperature.
The function can be enabled and confi gured manually or automatically.
• The automatic procedure involves the fast commissioning operation
described in chapter 7, which automatically confi gures the control
parameters on both the condensing unit and the evaporators, using
the default values optimised by CAREL, yet amply modifi able.
• To confi gure the function manually, make sure that there is a serial
connection with the MPXPRO or ULTRACELLA controllers on the
evaporators, and choose the type of control on screen Cab01. The
smooth lines function will then need to be confi gured on the MPXPRO
or ULTRACELLA controllers, as described in the next chapter.
Bekijk gratis de handleiding van Carel Hecu, stel vragen en lees de antwoorden op veelvoorkomende problemen, of gebruik onze assistent om sneller informatie in de handleiding te vinden of uitleg te krijgen over specifieke functies.
Productinformatie
| Merk | Carel |
| Model | Hecu |
| Categorie | Niet gecategoriseerd |
| Taal | Nederlands |
| Grootte | 10743 MB |
