59
ENG
mpxone +0300086EN rel. 2.2 - 13.11.2023
Functions
The purpose is to stop control and allow natural defrosts only when necessary.
When control stops in sequential stop mode, the defrost icon will come on, the defrost status will be sent to the supervisor and
the display will refl ect the setting of parameter d6.
Notice: the setting of parameter F3 has no eff ect. Evaporator fan management depends on parameter F0.
Skip defrost (par. d7, dn)
This function only has eff ect for defrosts that end by temperature. The skip defrost function evaluates whether the defrost dura-
tion is less than a certain threshold dn1 (dn2) and only if this condition is true will the following defrosts be skipped.
Code Description Def Min Max UOM User User terminal
dP1 Maximum defrost duration 45 1 240 min S YES
dP2 Max secondary evaporator defrost duration 45 1 240 min S NO
d7 Skip defrost 0 = disabled, 1 = enabled 001- SNO
dn Nominal defrost duration for skip defrost 75 0 100 % S NO
The purpose is to stop control and allow natural defrosts only when necessary.
When control stops in sequential stop mode, the defrost icon will come on, the defrost status will be sent to the supervisor and
the display will refl ect the setting of parameter d6.
Notice: the setting of parameter F3 has no eff ect. Evaporator fan management depends on parameter F0.
Skip defrost (par. d7, dn)
This function only has eff ect for defrosts that end by temperature. The skip defrost function evaluates whether the defrost dura-
tion is less than a certain threshold dn1 (dn2) and only if this condition is true will the following defrosts be skipped.
Code Description Def Min Max UOM User User terminal
dP1 Maximum defrost duration 45 1 240 min S YES
dP2 Max secondary evaporator defrost duration 45 1 240 min S NO
d7 Skip defrost
0 = disabled, 1 = enabled
001- SNO
dn Nominal defrost duration for skip defrost 75 0 100 % S NO
Thresholds dn1 (evaporator 1) and dn2 (evaporator 2) are defi ned by:
The algorithm keeps a counter of the defrosts to be skipped:
• if the defrost ends in a time less than dn1, the counter of the defrosts to be skipped is increased by 1;
• if the defrost ends normally, the next defrost is performed;
• when the counter reaches 3, three defrosts are skipped and then the counter is reset to 1;
• at power-on, the defrost is performed 7 times without increasing the counter, from the eighth on the counter is updated.
Power defrost (par. ddt, ddP)
Power defrost is used to increase the end defrost threshold dt1 (dt2 for the second evaporator) and/or the maximum defrost
duration dP1 (dP2 for the second evaporator). These increases allow more eff ective defrosts. Power defrosts are performed on
each defrost call during night status or when suitably confi gured by the RTC parameters (sub-parameter P of parameters td1 to
td8), so as to allow the user to choose the conditions that are most suitable for this special procedure. Power defrost is activated
when at least one of the increases, ddt or ddP, has any value other than zero.
Code Description Def Min Max UOM User User terminal
ddt Additional end defrost temperature delta in power defrost mode 0 -20 20 °C/°F S NO
ddP Additional maximum defrost time delta in power defrost mode 0 0 60 min S NO
td1..8-P Defrost 1 to 8 - enable power defrost:
0 = normal, 1 = power defrost
001- SNO
Notice: in power defrost mode, the maximum defrost durations dP1 and dP2 are increased by the value of parameter ddP.
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