Stulz C7000 - Page 70

70
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EN/06.2019/G57 © STULZ GmbH – all rights reserved
C7000 INSTRUCTIONS fOR A/C UNITS
The corresponding commands:
Components/Cooling
ICC/more/more
The following parameters are relevant for CyberRow units, version AS only:
If a CyberRow unit of the AS version is switched off at very low temperatures,
it can happen that after a certain time the refrigerant is displaced into the con-
denser. The little amount of refrigerant in the liquid receiver is shut off by the
non-return valve towards the condenser and by the electronic expansion valve
(EEV) towards the evaporator.
When the unit will be started after a few days, it can happen that there is only a
slight amount of refrigerant in the evaporator at low pressure, such as to cause
a low pressure alarm within a short time. As the required pressure difference
across the compressor can not be established due to the low pressure, the
EEV does not open either, so that there is no way for the refrigerant in the liquid
receiver to flow into the evaporator.
To prevent such a malfunction, a minimum pressure
➊ for the refrigerant circuit
can be set.
When the pressure as well on the suction side as on the discharge side is lower
than the adjusted minimum pressure while the compressor is to be started, the
EEV is opened before the compressor start request for an adjustable time
➌ on
an adjustable opening degree
➋.
During this time the refrigerant pressure in the circuit increases. After the EEV
has been closed (this is the pre-condition for the compressor start), the com-
pressor may start.
icc 1 pet 6
icc 1 peog 50
icc 1 pep 20
Config