Table of Contents
Advertisement
Specifications
Accuracy
The unused measurement input should be connected to the COM port of the terminal in order to make the
analysis as accurate as possible and minimize interference.
• Possible measuring inputs at the terminal:
◦ Voltage measurement 300 mV – 300 V (connection points 1 + 5)
◦ Current measurement 100 mA – 1 A (connection point 7)
◦ Current measurement 10 A (connection point 3)
The measuring accuracy depends on the type of signal to be measures and on the terminal settings.
The accuracy values specified in the following table apply to the default settings for the terminal parameters:
- Enable vendor calibration
- Enable filter
- Frequency
- Zero compensation interval
- Presentation
Signal to be measured
Measure-
Measuring range
ment type
DC
3 V - 300 V
8)
300 mV
7)
100 mA
1 A
10 A
4) 5)
AC
3 V - 300 V
300 mV
100 mA
1 A
10 A
Table 1: Measuring tolerances depending on temperatures. MBE = full scale value.
1) In 60 Hz mode of ADC 0.02 should be added to the specified tolerance
2) The values apply to a minimum terminal warm-up time of 30 minutes
3) The compensation temperature is 40 °C
4) All AC voltage and current ranges are specified for a range of 5% to 100%
5) Crest factor < 2
6) In 60 Hz mode an additional temperature drift of 20 ppm / °C is to be expected.
7) The maximum deviation under EMC test conditions according to IEC 61131 is 1 %
8) The maximum deviation under EMC test conditions according to IEC 61131 is 0.2 %
Measuring procedure
The measuring technique in the terminal is based on the dual-slope technique.
The Zero Offset Compensation function reads the internal ADC offset and corrects the analog value
accordingly. The additional temperature drift can thus be partly compensated, either cyclically or through
external control.
Operating conditions
• To avoid interference shielded cables must be used for the analog signals. The maximum cable length
is 30 m.
• For DC voltage measurements may the AC component may not exceed 150 V
EL3681
true
true
50 Hz
Off (0)
Scaled (1Bit/1µV) (2)
Typical max. tolerance in % of full scale
1)
value
3)
40°C
8)
0.01
0.05
0.1
0.1
0.2
0.25
0.25
0.5
0.5
0.5
Version: 3.0
Typical temperature drift
2)6)
0 .. 55°C
ppm/°C
0.2
35
0.2
35
0.5
50
0.5
50
1.2
170
0.75
130
0.5
50
1
50
0.7
50
1.2
150
Product description
.
pp
21
Advertisement
Table of Contents
