5.4.4 Continuous running monitoring
Controller type: UA 111, UA 111 D, UA 121, UA 131 DD, UA 141 only
Continuous running of refrigerated cases, e.g. in aggravated ambient conditions, has negative effects especially
withmultidecks.
It results in icing of the evaporator and reduced air curtain cooling. Run time continuous running monitoring
provides for automatic forced shutdown of cooling as a means of preventing icing. This limits the operating time
of the cooling.
ThedurationoftheseforciblyactuatedshutdownsissetviatheparameterCont Cool Mon.(menu6-3).
Commencement of forced shutdown is predefined. When necessary, forced shutdown always takes place 1.5
hoursaftercommencementofdefrostingandaftereachadditionalhour.
The following condition also applies:IfactualsupplyairtemperaturedropsbelowSupplyAirSetpoint+1Kin
one zone, continuous run monitoring is deactivated in this zone for one cycle (1.5 or 1 h).
5.4.5 Minimum on and off time
Short-cycling of cooling (i.e. the compressor) can occur when a small hysteresis is set, for example. Monitoring
is therefore incorporated to ensure definable minimum on and off times for cooling.
Moreprecisely,thismeans:
If cooling is stopped by the temperature setpoint being reached, it will remain off until the set minimum on time
has expired. If the temperature setpoint is not reached until after the minimum on time has expired, cooling will
then be stopped immediately. The same procedure applies to minimum off time before starting cooling.
5.4.6 E*COP+ (SDS TEV)
The auto-adaptive E*COP+ control process dynamically adjusts the suction pressure to the current cooling
power requirement. The algorithm evaluates the operating data of all controllers and determines the optimum
suction pressure over the respective requesting cooling units. The suction pressure p0 i.e. evaporation
temperature t0 is raised dynamically as far as possible.
The procedure makes use of the fact that an increase in p0 i.e. t0 requires less compression work. Dependent
on the operating status, raising the evaporation temperature by 1 K can save ca. 3 % energy. In the case of
fluctuating partial loads E*COP+ always finds the ideal operating point and improves the COP (Coefficient of
Performance).
InorderforthecasecontrollertobeincludedinthecontrolprocesstheparameterSDS TEVmustbesettoON
(see menu 6-7-1) and the corresponding pack number set (see menu 6-1).
When forced shutdown is active, it will be terminated before the set duration elapses if temperature
rises 4K on the supply air sensor R2.1.
Further details are contained in the pack controller operating manual.
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