Technical Manual Cold Storage Controller EVP 3150-1 and EVP 3150-2
Page 7
Cooling
Cooling control by Solenoid Valve / Compressor
Cooling is controlled by switching the output relay
contacts ON an OFF.
For freezing applications, the N/C contact can be
used (inverted mode) to secure permanent cooling
in case of a controller defect, adjustable by "
P03
"
(Mode Page).
The point of cut-off is always the valid setpoint. If the
temperature at the control sensor exceeds setpoint
+
hysteresis ("
r10
"
,
Setpoint Page)
,
the control relay
will switch on. "
P03
"
also affects to the switching
characteristic of the fan relay.
Do not use 'inverted', if compressors are
controlled directly. Risk of compressor
damage by continuous running!
The control relay can be locked via data interface.
Low temperature Limitation
Can be used e.g. for refrigerated shelfs with roller
blinds to limit the temperature at the air outlet during
night operation. When the temperature at the alarm
sensor decreases the limit set by "
r43
" (resp. "
r44
"
,
Setpoint Page) cooling will switch off.
This value is the threshold for the low temperature
alarm at the same time.
The low temperature limitation cannot be
switched off.
Runtime Monitoring
The controller monitors the total running hours of
the cooling output over 3 days. A 'day' is defined
as the period within "
P42
" and 1 minute before the
same point in time next day.
Example
:
"
P42
" set to 11:00 am =
Monitoring time range is from 11:00 o'clock day 1up
to 10:59 o'clock day 2.
The overall runtime of the cooling relay over a day
will be added and stored ("
L21
", Actual Values
Page). If this runtime exceeds the value set by "
r31
"
three days in a sequence, this will cause an alarm
at the hour programmed by "
P42
" (Mode Page).
The alarm relay will be de-activated and the alarm
LED switches on.
This alarm will be cancelled automatically 1
hour later.
Operation with a single compressor
If a single compressor is controlled by a refrigeration
relay, it is suggestive to have an idle time to prevent
the machine from damages caused by short cycle
operation. The compressor can restart only after the
timer "
r33
" (Setpoint Page) has been run down. The
remaining time up a restart can be read at "
L36
"
(Actual Values Page).
Temperature Alarm
If a relay gets the function "ALA", a temperature alarm
will be forwarded by the 'Quiescent current' principle.
After power-up of the controller, the alarm relay will
be energized after ~4 sec. In case of a failure the
relay will be de-energized after a delay timer (
"
r45
",
Setpoint Page) has
been run down. LED
"Alarm" shows the
alarm state. If tempe-
rature comes back to
the normal range, the
relay will be energized
again. "
L32
" shows
the remaining time up
to an alarm.
Overtemperature Alarm
It is possible to select max. 4 (5 with the 'virtual') alarm
sensors (e.g. 4x "
ALA
"). If the temperature at one of
the alarm sensors exceeds the control se the
"
r41
" (resp. "
r42
", Setpoint Page) setting, an alarm
will be initiated after the delay time "
r45
".
Low temperature Alarm
If the temperature at any alarm sensor gets lower
than the "
r43
" (resp. "
r44
"
,
Setpoint Page) setting,
an alarm will come on with the delay explained
above. This setting is an absolute value and does
not refer to the control setpoint. At the same time, this
setting works as threshold for the "low temperature
limitation" function.
Low temperature alarm can be disabled by "
P41
"
(Mode Page).
Supplementary alarm delay during defrost
After a defrost cycle the temperature may take longer
to stabilize and the normal alarm delay turns out to
be too short. For this reason the value of parameter
„
d33
“ (defrost page) will be added on to the normal
alarm delay after defrosting.
cooling relay normal
cooling relay inverted
Heating function
One relay is able to work as a heat relay. Then the
control setpoint is the cut-off of heating and cooling
at the same time. Cut-in will be:
•
for cooling:
se hysteresis (r10)
•
for heating:
setpoint - hysteresis (r10).
'Physical' and 'virtual' sensors
1. Each 'physical' (real) sensor is able to fulfill up to 3
functions at the same time (see Assignment Page),
any sensor is able to do the same job.
Up to 4 control sensors can be assigned the same
time. If
one of them
gets warmer than se
hysteresis, then cooling starts.
2. It is possible to create a 'virtual' sensor to realize
different kinds of averaging, e.g. multiple sensors in
a huge room or averaging of inlet and outlet sensor in
a chest freezer. The 'virtual' sensor resp. value (
L07
)
follows from the selectable emphasis of the sensors
which must have an effect on the result (
h17, h27,
h37, h47
, Assignment Page). The functions assigned
to this 'sensors' (
h71, h72, h73
, Assignment Page)
are the same as the functions for the 'physical' sen-
sors.
Example
: If the 'physical' sensor 1 got the function
"
con
" (control sensor) and also the 'virtual' sensor,
then the warmer one initiates refrigeration.
- Selection of a "virtual sensor":
- Assignment of a function by
h71-h73
- Selection of a 'physical' sensor which must have
an effect on the result :
- Activating of the sensor by assigning a
function (e.g. display only sensor)
- Set emphasis for the selected sensor
(
h17, h27, h37, h47
).
The sum of all emphasis values must be
100%.
Example
:
If sensor 1 and sensor 2 must have an effect
on the result and you set "
h17
" to "30%" and
"
h27
" to "60%", then you get the error message "
SEL
"
(assignment error).
Further causes for the error message "
SEL
"
- The sum of all emphasis parameters is 100%,
but no virtual sensor function is selected
- All 4 emphasis values are set to '0' and a
'virtual' sensor function is assigned
- A physical sensor is switched off, but an
emphasis value > 0 is selected.
Example 1, Chest Freezer:
For the detection of the actual value, inlet and outlet
sensor must be used. Sensor 1 is mounted at the
suction side (inlet) and must have an 60% influence
on the result. Sensor 2 is mounted at the outlet and
must have an 40% influence.
- set "
h17
" to "60"
- set "
h27
" to "40"
- set "
h71
" to "con" (control sensor)
Example 2, huge room, standard application
Sensors 1-3 must measure the rooms temperature,
an arithmetic average must be calculated, sensor 4 is
the defrost limitation sensor in the evaporator.
- set "
h17
", "
h27
" to "33" and "
h37
" to "34"
- set "
h71
" to "con" (control sensor)
- set "
h41
" to "df1"
Special Function
If an emphasis parameter value is set to
100% (others to 0), up to 6 functions can
be assigned to the corresponding physical sensor.
This may be of interest for applications where
more than 3 sensor functions are used.
M
L
M
L
cooling
fan
cooling
fan
P03 set to 'nor'
P03 set to 'in'
active-
passive
phase
cooling = relay on
relay on
freezing=
relay off
cold
warm
warm
cold
setpoint
setpoint
Hysteresis
Hysteresis
relay off
refrig. on
Heizen ein
cold
warm
off
setpoint
Hysteresis
Hysteresis
