ECKELMANN UA 400 - Page 36

Firmware V3.15
21.04.2021
36/401
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Separate defrost start according to the two temperature zones using the internal defrost timer
Usually it is sufficient if the defrost is started simultaneously for both zones. However, should an application
require it, a separate defrost for each zone can be carried out. Additional parameters are available for this
purpose.
In the E*LDS system, defrost time refers to the time for the start of a defrost. In order to activate separate
defrosttimesforthetwotemperaturezonestheparameterDefrost Timermustbesetto"INT"(menu3-2-a).
Theparametersavailableforthisfunction,„Safe Defr Time" and "Defrost 1..14"areidenticaltothoseforthe
first zone and can be set as usual.
Defrost termination
Defrosting can be terminated by three methods:
By defrost termination temperature being obtained
By completion of safe defrost time
By command signal from the pack controller via CAN bus (UA 131 DD, UR 141 TK (LT) only)
Defrost termination by obtaining defrost termination temperature depends on the set controller types as
described below:
UA 121Everyevaporatorhasanevaporatorsensor.Single-zone operation:Onedefrostrelayswitchesthe
heatersof1-4evaporators.Two-zone operation:Twodefrostrelaysswitchtheheatersof1-2evaporators
each for 2 zones.
UA 131, UA 131 DDDefrostingisterminatedseparatelyforeachevaporatorbythetemperatureonthe
respective evaporator sensor. Defrosting is terminated via the evaporator sensor at least four minutes after
the initiation of the defrosting. This applies for initiation via the external contact as well as for initiation via
the CAN bus.
UR 141 NK (NT)Defrostingisterminatedseparatelyforeachevaporatoraccordingtothetemperatureon
the respective evaporator sensor (when only one evaporator sensor is fitted) or on both evaporator sensors
(when two are fitted). This means that as many as four evaporators can be connected to the controller with
off-cycle defrosting.
UR 141 TK (LT)ConditionsarethesameasfortheUR141NK(NT).However,withdefrostingbyelectric
heater only two evaporators can be connected to the controller, because defrosting is controlled through
only two defrost relays.
UA 111, UA 111 D, UA 141Defrostingisterminatedjointlyforallevaporatorswhendefrosttermination
temperature is obtained on each supply air sensor connected.
Demand defrosting (controller type UA 131, UA 131 DD, UR 141 TK (LT) only)
Demand defrosting means that a decision is made, depending on duration of a previous defrosting cycle,
whetherdefrostingisactuallyinitiatedorskippedonbecomingdue.
A defrost counter is set to 6 at the commencement of defrosting and counts down as a function of the set
counting rate until temperature on the evaporator sensor of the pilot case is in the range between -3 °C and +3
°C. Setting the counting rate to 0 deactivates demand defrosting. If the counting rate is set low, the demand
defrostcounterwillcountdownfasterto1.Thismeansthatalldefrostcyclesareindeedinitiatedwhendue.Ifa
highercountingrateisset,moredefrostcycleswillbeskipped(maximum5cycles).Ifahotgasdefrostis
carried out then the defrost counter for the demand defrost is reset.
The simultaneous deployment of separate defrost zones and the master/slave function is not
recommended! If these functions are nevertheless used together, it should be noted that, depending on
the parameterization, this can result in very long defrost phases!
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Defrosting is always terminated by the safe defrost time when defrost termination temperature is set to
--. In this instance, no time defrost termination alarm is entered in the alarm log.
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