EVCO S.p.A.
EVDRIVE04 | User manual ver. 4.0 | Code 144EPDE404
page 64 of 78
9.8
Superheat algorithm protection functions
9.8.1
LoSH
When enabled (Pa10), this alarm is triggered when the SH drops below the low heating threshold (Pc02, Pp02, Pd02).
The condition is signalled in the Algorithm status (AlgS) and, when the timeout (Pa12) expires, an alarm is set.
The alarm and signal are cleared automatically when the SH returns above the threshold (hysteresis defined in Pa11).
9.8.2
HiSH
When enabled (PA20), this alarm is triggered when the SH rises above the high heating threshold (Pc03, Pp03, Pd03),
a bit is set in Algorithm status (AlgS) and, after the timeout (Pa22) expires, an alarm is set. The alarm and signal are
cleared automatically when the SH returns below the threshold (hysteresis defined in Pa21).
9.8.3
LOP
When enabled (parameter Pa40), this alarm is triggered when the evaporation temperature (Te) drop below the LOP
threshold (parameters Pc04, Pp04) and in the
Start-Up
(41) status activates a specific algorithm for managing the
LOP, forcing the valve to open 100%, and in case of alarm re-entry stopping it at the current opening.
The condition is signalled in the
Algorithm status
(AlgS) and, when the timeout (Pa42) expires, an alarm is set.
This protection is most useful during start-up of the machine, when the evaporation temperature is effectively low.
It is possible to optimise this phase by setting a correct value in the valve opening on start-up parameter (parameters
Pc21, Pp21). When the Te temperature returns within its limits (parameter Pa41 defines the hysteresis), the alarm and
signalling are cleared and the normal regulation algorithm resumes.
9.8.4
MOP
When enabled (parameter Pa50), once the
Delay Bypass MOP
(parameter PA56) has elapsed since the activation of
the regulation algorithm, this alarm is triggered when the evaporation temperature (Te) rise above the MOP threshold
(parameters Pc05, Pp05) and activates a specific algorithm for managing the MOP, that increasing the superheat
setpoint (parameters PA53, PA54, Pa55).
The MOP correction algorithm can force the opening of the valve, closing it of
MOP forced delta
(parameter Pa57) each
MOP forced time
(parameter Pa58) seconds. This function is disabled if
MOP forced delta
(Pa57 parameter) is null.
The condition is signalled in the
Algorithm status
(AlgS) and, when the timeout (parameter Pa52) expires, an alarm is
set. When the Te temperature returns within its limits (parameter Pa51 defines the hysteresis), the alarm and its
signal are cleared and the normal regulation algorithm resumes.
9.8.5
LowPressure
When enabled (Pa30), and the evaporation pressure (Pe) falls below the low pressure threshold (Pa31), an warning is
signalled. After the timeout (Pa33) expires, the LP alarm is set. The alarm and its signal are cleared automatically
when the pressure returns above the threshold. (Pa32 defines the hysteresis).
