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Defrost output
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Valve used in STD-ALONE mode
The activation of the digital defrost input is only effective if the adjustment request digital input is already
active.
In STD-ALONE mode, the IEV does not carry out any check on the operating status of the chiller or the
heat pump; if the digital defrost request input is active, the IEV will set itself to the defrost adjustment
mode regardless of the active operating status at the time.
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Defrost input
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1592026270 IEV12-14D GB r.1.0 21.02.2019
during the initial stage, during the Et53 / Et55 time calculated from
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when the defrost starts, if the adjustment of the valve requires an
aperture value below the step number set under parameter Et52 /
Et54, the valve will not close at a value below Et52 / Et54 (which is
therefore the minimum aperture threshold in the initial defrost stage).
Once the Et53 / Et55 time has elapsed, the adjustment will go ahead
as it normally does for defrost.
Ichill turns off the compressor(s) before reversing the gas cycle and going back to
heating mode (heat pump)
when Ichill turns off the compressors after completing the defrost, the
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valve closes
when Ichill requests the switch-on of the compressors for the input
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undergoing adjustment in heating mode (heat pump), the valve opens
at the step number set under parameter Et1 / Et4 and maintains this
position for the time set under Et43 before providing the consent to
Ichill to turn on the compressors
once the Et43 pre-aperture time has elapsed, the valve performs
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adjustments in accordance with the heating mode (heat pump)
Ichill does not turn off the compressor(s) to go back to heating mode (heat pump)
when Ichill completes the defrost stage and switches to adjustment in
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heating mode (heat pump), the valve maintains the step number it
currently has for the time set under the Et43 parameter
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once the Et43 time has elapsed, the valve performs adjustments in
accordance with the heating mode (heat pump)
The digital defrost input is activated by maintaining the adjustment request active
When the digital defrost request input is activated, the valve starts
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adjusting according to the chiller mode, though the proportional
component is provided by the specific Et51 defrost parameter
During the initial stage, during the Et53 / Et55 time calculated from
▪
when the defrost starts, if the adjustment of the valve requires an
aperture value below the value of parameter Et52 / Et54, the valve will
not close at a value below Et52 / Et54 (which is therefore the minimum
aperture threshold in the initial defrost stage). Once the Et53 / Et55
IEV
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