ECKELMANN UA 400, Operating Instruction

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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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