Evco EVDRIVE03 - Page 59

EVCO S.p.A. EVDRIVE03 | User manual ver. 3.6 | Code 144EPDE364
page 59 of 76
An alternative to the backup battery, a solenoid valve connected to the relay may be used to block the flow of the
refrigerant.
9.7 Algorithm status
Bit 10 of Alarm status (AlSt) is raised for LOP, MOP, LoSH, HiSH, LowPressure or if the measures needed by the
algorithm are not valid.
This monitoring is in effect only while the system is working in SH-algorithm and in manual mode.
The Algorithm status (AlgS) variable holds the specific state that generated the alarm, according to this table:
Algorithm status Description
Value 0 Value 1
bit 0 Measures acquired Data not read (Alarm status.b10 0
→
1)
bit 1 algorithm is running control algorithm halted
bit 2 algorithm is active algorithm is skipped (manual mode is active)
bit 3 No LoSH algorithm is running LoSH algorithm is running
bit 4 No LoSH alarm LoSH alarm (Alarm status.b10 0 > 1)
bit 5 No HiSH algorithm is running HiSH algorithm is running
bit 6 No HiSH alarm HiSH alarm (Alarm status.b10 0 > 1)
bit 7 No LOP algorithm is running LOP algorithm is running
bit 8 No LOP alarm LOP alarm (Alarm status.b10 0 > 1)
bit 9 No MOP algorithm is running MOP algorithm is running
bit 10 No MOP alarm MOP alarm (Alarm status.b10 0 > 1)
bit 11 No LowPressure LowPressure (warning signal only)
bit 12 No LowPressure alarm LowPressure alarm (Alarm status.b10 0 > 1)
Note that if the manual mode is active, a read error of the measurement data due to incorrect probe configuration only
generates a warning. While, if the control algorithm is running, the inability to read the measurements makes it
impossible for the algorithm to continue, so this triggers a probe alarm.
Bits 0 and 1 of Algorithm status (AlgS) are always calculated, while the other bits, given their dependencies on the
active control algorithm, are only valid while SH-algorithm is running.
9.8 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 (Pa40), this alarm is triggered when the evaporation temperature (Te) drop below the LOP threshold
(Pc04, Pp04, Pd04). 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