ECKELMANN VS 3015 CT, Инструкция по эксплуатации, Страница: 36 / 219

Firmware V1.41 V1 08.11.2022 36/219
t
0_max
, t
0_min
, t
r_min
and t
r_max
can be parametrised. The air humidity can also be taken into account via the
analogue input 7 (terminals 59/61). The setpoint for the pressure for the actual regulation is determined from a
conversion table stored in the firmware. For the conversion of p
0
to the corresponding temperature value t
0
, the
refrigerant characteristic curve for CO
2
is used: t
0
=f(po, R744)
5.4.4.2 Setpoint Shift - Demand-Dependent via Consumer
In order to guarantee optimum operation of a compressor pack with the associated refrigeration points with
minimal operating costs, it is advisable that the suction pressure regulated by the compressor pack is set
depending on the refrigeration needs of the refrigeration points (Consumers, menu 3-2-1-2).
Here, in the case of controllers with electronic expansion valves, the opening degree of the refrigeration point
expansion valves can be used as a reference variable. In the case of controllers with thermostatic expansion
valves, information equivalent to the opening degree is determined by the UA 300/UA 400 controller.
If a configurable maximum load level (parameter Max.LoadLevel , menu 3-2-1-2) is exceeded on at least one of
the associated refrigeration points for the pack, it can be assumed that it is no longer possible to reliably
maintain the temperature at this/these refrigeration point(s) with the existing suction pressure. In this case, the
suction pressure is reduced in order to provide adequate refrigeration.
Conversely, if all of the associated refrigeration points for the pack exhibit a load level smaller than the
configurable minimum load level (parameter
Min.LoadLevel , menu 3-2-1-2), it can be assumed that the
refrigeration capacity provided by the pack is more than sufficient. In this case, in the interest of energy efficient
operation of the system, the suction pressure is increased. The adjustment of the suction pressure setpoint is
performed within configurable limits (parameters
to-Min., to-Max., , menus 3-2-1-3 and 3-2-1-4) using a
configurable step size for the increase and reduction of the t
0
setpoint (parameters Increment and Decrement ,
menu 3-2-1-2) and a configurable updating interval (parameter Interval , menu 3-2-1-2). If the refrigeration of a
case is subject to a forcibly actuated shutdown (defrost, external OFF etc.), the associated case controller does
not influence the to shift.
The same applies if the corresponding control sensor (supply air/return air/room air temperature) on the case
controller fails.