XT Controllers for NLV-CN Compressors
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As soon as the logger is full, the oldest logs will be
deleted and overwritten with a new log.
To limit at a certain number of logs, it is possible to
set up thresholds for the logging range.
Logging of temperatures outside a predefined
range:
As soon as the logger is full, the oldest logs will be
deleted and overwritten with a new log.
To limit at a certain number of logs, it is possible to
set up thresholds for the logging range.
Logging of temperatures outside a predefined
range:
Logging area
Logging area
Low Threshold" (h03)
Logging area
Low Threshold" (h03)
Parameter Function Code
Multiple
Apps
Min. Max.
Default
Setting
Unit
Log interval h01 x 15 240 30 Min.
High threshold for logging h02 x
-50°C or
-58°F
50°C or
122°F
-50 °C/°F
Low threshold for logging h03 x
-50°C or
-58°F
50°C or
122°F
50 °C/°F
Selection of sensor for the logger function
0 = No logging function defined
1 = S1/S2 temperature
2 = T
alarm
temperature
3 = T
act
temperature
4 = S4 temperature
5 = S3 temperature
h11 x 0(0.1)
3
(1.0)
1 -
Alarm limit for the logger function h12 x
-50°C or
-58°F
7 60 °C/°F
Time delay for the alarm h13 x 1 6 60 Min.
If the “Low Threshold” (h03) is set higher than the “High Threshold” (h02), only temperatures inside these
limits will be logged.
If the “Low Threshold for logging” and “High Threshold for logging” are set equal, no logging will be
performed.
Furthermore, the temperature logger contains a separate high alarm function (h12) with adjustable alarm
delay (h13).
Restrictions:
The maximum number of logs is limited to 1,000.
In the event of a sensor error on the selected temperature probe, there will be no logging. Instead, a
sensor error alarm will be generated.
4.5.
Reference for the
Capacity Controller
The purpose of the reference function is to generate a reference for the compressor capacity controller
and to create the limits for the temperature setting range during the day and nighttime. Based on the
deviation between the actual temperature T
act
, compared to the temperature reference T
ref
, the capacity
controller will increase or decrease the requested compressor capacity. The bigger the deviation, the
faster the requested compressor capacity will be adapted.
Measurement and calculation of actual cabinet temperature T
act
:
The cabinet temperature can be measured with either S1, S2 or in special applications as a weighted
combination of both. In the event of incorrect temperature measurements due to wrong placement of the
sensors, both temperature inputs include an offset adjustment possibility. “S1 temperature offset” (r10)
and “S2 temperature offset” (r09).
For the cabinet temperature measurement, with S1 and S2, a weighting of these 2 sensors is
implemented. Please refer to the chapter Temperature Acquisition.
Calculation of T
ref
Tset r01
Tref
Max.
Max.
Min.
Min.
Night
Night offset
U28
r25
r03
r13
r02
r26
Tset
Limit
Tref
Limit
Parameter Function Code
Multiple
Apps
Min. Max.
Default
Setting
Unit
T
set
r01 x -49 Qqy -20 °C
Max. limitation of reference T
set
r02 x -49 50 -15 °C
Min. limitation of reference T
set
r03 x -50 49 -27 °C
Max. limitation of reference T
ref
r25 x -49 50 -15 °C
Min. limitation of reference T
ref
r26 x -50 49 -27 °C
T
set
nighttime temperature offset r13 x -10 10 0 °K
Switch between sensor S2 and S4
Note: All parameter names are listed for value
0 (S2)
o18 x 0 = S2 1 = S4 1 -
The temperature reference T
ref
for calculating the reference for the PID controller is calculated as follows:
T
ref
=
T
set
+ “Nighttime temperature offset” (r13)
The setting range of
T
set
can be limited with the 2 parameters “T
set
max” (r02) and “T
set
min” (r03).
To avoid a temperature reference too high or too low, the allowed temperature reference band is limited
with the following 2 set points: “T
ref
min” (r25) and “T
ref
max” (r26).
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