39
ENG
“EVD evolution” +030222041 - rel. 1.0 - 01.06.2008
Parameter/description
Def. Min.
Max.
UOM
SONDE
Pressure S1: MINIMUM alarm
value (S1_AL_MIN)
-1
-20 (-290)
S1_AL_MAX barg
(psig)
Pressure S1: MAXIMUM alarm
value (S1_AL_MAX)
9,3
S1_AL_MIN 200 (2900)
barg
(psig)
Temperature S2: MINIMUM
alarm value (S2_AL_MIN)
-50
-60
S2_AL_MAX °C/°F
Temperature S2: MAXIMUM
alarm value (S2_AL_MAX)
105 S2_AL_MIN 200 (392)
°C (°F)
Pressure S3: MINIMUM alarm
value (S3_AL_MIN)
-1
-20
S3_AL_MAX barg
(psig)
Pressure S3: MAXIMUM alarm
value (S3_AL_MAX)
9,3
S3_AL_MIN 200 (2900)
barg
(psig)
Temperature S4: MINIMUM
alarm value (S4_AL_MIN)
-50
-60
S4_AL_MAX °C/°F
Temperature S4: MAXIMUM
alarm value (S4_AL_MAX)
105 S4_AL_MIN 200 (392)
°C (°F)
Tab. 9.c
The behaviour of the driver in response to sensor alarms can be
configured, using the manufacturer parameters. The options are:
no action (control continues but the correct measurement of the
•
variables is not guaranteed);
forced closing of the valve (control stopped);
•
valve forced to the initial position (control stopped);
•
use the backup sensor (valid only for sensor S1 and S2 alarms, control
•
continues).
Parameter/description
Def.
CONFIGURATION
Sensor S1 alarm management:
No action
Forced valve closing
Valve in fixed position
Use backup sensor S3
Valve in fixed position
Sensor S2 alarm management:
No action
Forced valve closing
Valve in fixed position
Use backup sensor S4
Valve in fixed position
Sensor S3 alarm management:
No action
Forced valve closing
Valve in fixed position
No action
Sensor S4 alarm management:
No action
Forced valve closing
Valve in fixed position
No action
CONTROL
Valve opening at start (evaporator/valve capacity
ratio)
50
Tab. 9.d
Control alarms
9.4
These are alarms that are only activated during control.
Protector alarms
The alarms corresponding to the LowSH, LOP, MOP and HiTcond
protectors are only activated during control when the corresponding
activation threshold is exceeded, and only when the delay time defined
by the corresponding parameter has elapsed. If a protector is not enabled
(integration time= 0 s), no alarm will be signalled. If before the expiry
of the delay, the protector control variable returns back inside the
corresponding threshold, no alarm will be signalled.
Note:
this is a likely event, as during the delay, the protection
function will have an effect.
If the delay relating to the control alarms is set to 0 s, the alarm is
disabled. The protectors are still active, however. The alarms are reset
automatically.
Low suction temperature alarm
The low suction temperature alarm is not linked to any protection function.
It features a threshold and a delay, and is useful in the event of sensor or
valve malfunctions to protect the compressor using the relay to control
the solenoid valve or to simply signal a possible risk. In fact, the incorrect
measurement of the evaporation pressure or incorrect configuration
of the type of refrigerant may mean the superheat calculated is much
higher than the actual value, causing an incorrect and excessive opening
of the valve. A low suction temperature measurement may in this case
indicate the probable flooding of the compressor, with corresponding
alarm signal. If the alarm delay is set to 0 s, the alarm is disabled. The alarm
is reset automatically, with a fixed differential of 3°C above the activation
threshold.
Relay activation for control alarms
As mentioned in the paragraph on the configuration of the relay, in the
event of LowSH, MOP, HiTcond and low suction temperature alarms,
the driver relay will open both when configured as an alarm relay and
configured as a so alarm relay. In the event of LOP alarms, the
driver relay will only open if configured as an alarm relay.
Parameter/description
Def.
Min.
Max.
UOM
CONTROL
LowSH protection: threshold
5
-40 (-72) superheat
set point
K (°R)
LowSH protection: integration time
15
0
800
s
LOP protection: threshold
-50
-60 (-76) MOP:
threshold
°C (°F)
LOP protection: integration time
0
0
800
s
MOP protection: threshold
50
LOP:
soglia
200 (392)
°C (°F)
MOP protection: integration time
20
0
800
s
SPECIAL
HiTcond: threshold
80
-60 (-76) 200 (392)
°C (°F)
HiTcond: integration time
20
0
800
s
ALARM CONFIGURATION
Low superheat alarm delay (LowSH)
(0= alarm disabled)
300
0
18000
s
Low evaporation temperature alarm
delay (LOP)
(0= alarm disabled)
300
0
18000
s
High evaporation temperature alarm
delay (MOP)
(0= alarm disabled)
600
0
18000
s
High condensing temperature alarm
delay (HiTcond)
(0= alarm disabled)
600
0
18000
s
Low suction temperature alarm
threshold
-50
-60 (-76) 200 (392)
°C (°F)
Low suction temperature alarm
delay
300
0
18000
s
Tab. 9.e
EEV motor alarm
9.5
In the event of incorrect connection or damage to the valve motor, an
alarm will be signalled (see the table of alarms) and the driver will go into
wait status, as it can longer control the valve. The alarm is indicated by
the LED NET and is reset automatically, after which control will resume
immediately.
Important:
after having resolved the problem with the motor,
it is recommended to switch the driver off and on again to realign the
position of the valve. If this is not possible, the automatic procedure for
synchronising the position may help solve the problem, nonetheless
correct control will not be guaranteed until the next synchronisation.
