ECH 200 BD
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If the machine is configured with 2 compressors, both compressors (steps) will be on during defrosting.
This will not be the case if a thermal switch alarm has been given for one of the compressors.
Compressor safety times are ignored during the defrost cycle.
Start defrosting and end defrosting pressure (or temperature) values are determined by:
• defrost start: parameter Pa d02
• defrost end: parameter Pa d04
this only applies if parameter Pa H49= 3 or 2.
If Pa H49= 1 (temperature-based operation), temperature values are determined by:
• Pa d08, start defrost
• Pa d09, stop defrost.
If Pa H49= 0, defrosting is not permitted (probe AI3 absent).
9.2.2 Defrost end
Defrost will end if:
• temperature/pressure rises above Pa d04 (defrost end temperature/pressure).
• duration of defrosting reaches Pa d05 (max defrost time)
at the end of defrosting, if drip time Pa d07= 0, the compressor will stay on; if not, the control illustrated in the figure will
be applied:
FD: defrost end
COMPR: compressor
RV: reversing valve
Pa d07: drip time
9.2.3 Counter mode
• The defrost interval counter is interrupted when temperature/pressure rises above Pa d02 (defrost start
temperature/pressure) or the compressor is turned off.
• The counter is set to zero after one of the following events: defrost cycle performed; power off; change in
operating mode.
• The counter is also set to zero when the temperature/pressure rises above Pa d04 (defrost end
temperature/pressure).
9.2.4 Start defrost temperature compensation
In dry and cool climates, the start defrost temperature is not corresponding to the effective icing temperature of the
battery. The following control allows to linearly compensate the start defrost temperature/pressure, by adding negative or
positive values depending on the outdoor temperature.
Fan control will be on if:
• Activation parameter Pa H31 = 1
• Probe AI4 is configured as an outdoor temperature probe (Pa H08= 3)
Control parameters:
• Pa d11 = compensation offset for temperature/pressure defrosting
• Pa d12 = compensation set point for temperature/pressure defrosting
• Pa d13 = compensation delta for temperature/pressure defrosting
Diagram
Decalibrating
defrost start
setpoint according
to T ext
Pa d07
ON
OFF
ON
OFF
COMPR
RV
Pa d07
FD
Pa d13 < 0
Pa d12
Pa d11 > 0
Temp
Pa d12
Pa d11 < 0
Temp
Pa d13 > 0
Pa d13 < 0
Pa d13 > 0
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