Menu Alarms - Hitecsa ADVANCE EQS Mode D'emploi

Low outdoor air temperature prevention
If enabled, the prevention of low external air temperature behaves similarly to that
of high pressure, reducing the power of the circuit when the outdoor air
temperature falls below the set threshold.
Foam prevention for flooded evaporator
On units with heat exchanger with flooded type shell and tube it is possible to
enable a function that makes it possible to prevent foam from forming.
Prevention is activated by the low delivery superheat alarm (see paragraph
III.1.9.20) or in the event that when the board is turned on the unit is kept off to
allow heating of the compressor crankcase oil (see paragraph III.1.9.17). The
action of this prevention is to limit the power delivered upon activation of the circuit
for the amount of time set on the screen.III.1.9.20III.1.9.17
III.1.9

Menu Alarms

In the Alarms menu it is possible to edit the settings referring to the machine's limit
operating conditions, beyond which the compressors are forced to stop.
The alarms may only be cleared when the conditions that triggered them are no
longer present. As described in paragraph I.1, the alarms can be reset
automatically when the conditions return, manually by pressing the Alarm button
for a long time, or semi-automatically; in this case it is possible to set a maximum
number of automatic rearms that can be performed in a time window of 60
minutes and for some of 24 hours: in this way it is ensured that the unit can start
again autonomously after some alarm situations but that these cannot occur in
this way frequently to jeopardize long-term reliability.I.4
III.1.9.1 Low pressure alarm
The low pressure alarm from transducer in cooling mode does not have a fixed
threshold, but variable according to the outlet temperature of the primary heat
exchanger. The colder the water, the lower the alarm threshold.
The alarm threshold is calculated on a straight line defined by 2 values: the first
point is given by the threshold of the alarm when the temperature is equivalent to -
8°C; the second point is given by the alarm threshold when the temperature is
equivalent to +7°C. The threshold is limited towards a high value calculated at
+15°C and at a low value calculated at -10°C.
Low pressure alarm threshold with circuit in cooling mode and primary
1
outlet temperature equal to -8°C
Low pressure alarm threshold with circuit in cooling mode and primary
2
outlet temperature equal to +7°C
Low pressure alarm threshold with circuit in heating mode or off
3
Differential for alarm reset
4
Threshold immediate intervention
5
It is possible to set the low pressure alarm bypass from the transducer in screen
Ji02, based on the unit's operating mode.
USM_CONTROL EQS_2335a21275_208549_210701_ES-EN-FR-DE-IT
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2
3
4
5
In window Ji03 it is possible to set, for the cooling mode and heating mode, the
number of possible resets of the low pressure alarm from transducer. The low
pressure alarm from pressure switch, however, is manually reset.
The graph below indicates the low pressure (LP) alarm threshold trend with cooling
and heating and the LP prevention threshold trend. Note on the Cartesian plane the
points set in the example window.
ThrLPalarmCH
ThrLPalarmPDC
ThrLPdefrost
AreaLPprevent
AreaLPalarm
LPalarmStdT
LPalarmBT
OffsetTiLOP
WaterTemp
EvapSatTemp
In window Ji04 it is possible to set the threshold triggering the high pressure alarm
from transducer (which is triggered with no delay) and the number of permitted
automatic resets. The high pressure alarm from pressure switch, however, is
manually reset and in addition to pressing and holding the Alarm key it requires
manually releasing the mechanical pressure switch.
1
2
3
4
5
The LOP alarm does not have a fixed threshold, but variable according to the outlet
temperature of the primary heat exchanger. The colder the water, the higher the
alarm threshold.
The alarm threshold is calculated on a straight line defined by 2 values: the first
point is given by the antifreeze threshold minus the first offset set as the parameter
at the temperature that establishes the antifreeze threshold; the second point is
defined by the antifreeze threshold minus a second offset set as the parameter at
the temperature established as the antifreeze threshold +10°C.
The LOP alarm bypass is variable according to the temperature of the refrigerant
condensation temperature. The lower the temperature, the lower the alarm's
bypass.
The bypass has a higher value on the alarm threshold. On the alarm bypass less
a differential, the bypass has a smaller value. The bypass varies linearly in the
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intermediate points.
2
3
4
5
93
Low pressure alarm bypass after a cycle change
Low pressure alarm bypass at thawing start.
Alarm bypass with respect to circuit activation
Alarm bypass during operation
Alarm reset delay
Low pressure alarm threshold when cooling [°C]
Low pressure alarm threshold when heating [°C]
Immediate thawing threshold [°C]
Low pressure prevention tripping area when cooling
Alarm tripping area and low pressure prevention
Low pressure alarm threshold at +7°C
Low pressure alarm threshold at -8°C
Differential to calculate the low pressure threshold
Water temperature [°C]
Evaporation saturation temperature [°C]
III.1.9.2 High pressure alarm
III.1.9.3 LOP alarm (low operating pressure)
CONTROL EQS