Alarm Parameters - Carel MPXPRO User Manual

9.5 Alarm parameters

Assign probe for high and low temperature alarms
(parameters AA, AA2)
AA selects the probe to be used for measuring the high and low
temperature alarms with reference to thresholds AL and AH. AA2 is the
same as AA for thresholds AL2 and AH2.
Par Description
AA Assign probe for high (AH) and low (AL)
temperature alarms
1=control (Sreg) 8 = auxiliary defrost (Sd2)
2=virtual (Sv) 9 = auxiliary (Saux)
3=outlet (Sm) 10 = auxiliary 2 (Saux2)
4 = defrost (Sd) 11 = ambient temp. (SA)
5 = intake (Sr) 12 = amb. humidity (SU)
6 = gas surrisc. (tGS) 13 = glass temp. (Svt)
7 = saturated evap.
14 = dewpoint (SdP)
temp. (tEu)
AA2 Assign probe for high (AH2) and low (AL2)
temperature alarms - see AA
Alarm parameters and activation
AL (AH) is used to determine the activation threshold for the low (high)
temperature alarm LO (HI). The value set for AL (AH) is continuously
compared against the value measured by the probe defi ned by parameter
AA. Parameter Ad represents the alarm activation delay, in minutes; the
low temperature alarm (LO) is activated only if the temperature remains
below the value of AL for a time greater than Ad. The alarm may relative
or absolute, depending on the value of parameter A1. In the former case
(A1=0), the value of AL indicates the deviation from the set point and thus
the activation point for the low temperature alarm is: set point - AL. If the
set point changes, the activation point also changes automatically. In the
latter case (A1=1), the value of AL indicates the low temperature alarm
threshold. The low temperature alarm active is signalled by the buzzer
and code LO on the display. The same applies to the high temperature
alarm (HI), with AH instead of AL. The meaning of parameters AL2, AH2,
AA2 and A2 is similar to AL, AH, AA, A1, relating to St2.
Par Description
AL Low temperature alarm threshold
If A1=0, AL=0: alarm disabled
If A1=1, AL=-50: alarm disabled
AH High temperature alarm threshold If A1=0,
AH=0: alarm disabled
If A1=1, AH=50: alarm disabled
AL2 Low temperature alarm 2 threshold
If A2=0, AL2=0: alarm disabled
If A2=1, AL2=-50: alarm disabled
AH2 High temperature alarm 2 threshold
If A2=0, AH2=0: alarm disabled
If A2=1, AH2=50: alarm disabled
A1 Alarm thresholds (AL, AH) relative to the set
point St or absolute
0 = relative; 1 = absolute
A2 Alarm thresholds (AL2, AH2) relative to the
set point St2 or absolute
0 = relative; 1 = absolute
A0 High and low temperature alarm reset
diff erential
Ad Delay time for high and low temperature
alarms
A7 Delay time for delayed external alarm
A6 Confi gure solenoid/compressor control
during external alarm (immediate or
delayed) with fi xed 15 min OFF time
0 = always OFF; 100 = always ON
Def Min Max UM
1 1 14 -
5 1 14 -
Tab. 9.c
Def Min Max UoM
4 -50.0 50.0 °C/°F
10 -50.0 50.0 °C/°F
0 -50.0 50.0 °C/°F
0 -50.0 50.0 °C/°F
0 0 1 -
0 0 1 -
2.0 0.1 20.0 °C/°F
120 0 240 min
0 0 240 min
0 0 100 min
Tab. 9.d
65
Note:
• alarms LO(LO2) and HI(HI2) have automatic reset. A0 represents the
hysteresis between the alarm activation value and deactivation value;
• if Prg/mute is pressed when the value measured is above one of the
thresholds, the buzzer is immediately muted, while the alarm code
and the alarm output, if set, remain active until the value measured
is outside of the activation threshold. For delayed alarms from digital
input (A4=3, code dA), the contact must remain open for a time greater
than A7. In the case of an alarm event, a counter starts and generates
an alarm when reaching the minimum time A7. If during the count
the value measured returns within the threshold or the contact closes,
the alarm is not signalled and the count is reset. When a new alarm
condition occurs, the count starts from 0 again. Parameter A6 has a
similar meaning to parameter c4 (duty setting). If an external alarm
occurs (immediate or delayed) the compressor works for a time equal
to the value set for A6 and remains off for a fi xed time of 15 minutes.
LO
ON
OFF
A0
AL
LO2
ON
OFF
A0
AL2
Key
LO, LO2 Low temperature alarms
HI, HI2 High temperature alarms
Enable valve alarm at end travel ('blo')
Parameter P14 is used to enable/disable the valve blocked alarm signal
('blo').
Par. Description
P14 Enable valve alarm at end travel ('blo')
1 = signal enabled
Signal alarms from Slave to Master
Master controllers, if Ar=1, can indicate a Slave with an alarm in the tLAN
network. If an alarm occurs on a Slave, the Master shows the signal "nx",
alternating with the temperature display, where x is the address of the
Slave with the alarm (x=1 to 5). If the Master has the AUX1, AUX2 or AUX3
relay confi gured as the alarm relay, then the alarm relay on the Master is
activated.
Par. Description
Ar Signal alarms from Slave to Master
0 = not enabled; 1 = enabled
ENG
HI
S1
A0
AH
HI2
S2
A0
AH2
Fig. 9.b
S1, S2 Probes
Def Min Max
1 0 1
Tab. 9.e
Def Min Max
1 0 1
Tab. 9.f
MPXPRO - + 0300055EN rel. 1.1 30/08/10
UoM
-
UoM
-