Product overview
EL3783
15
Version: 1.1
2.3
Technology
Measurement of AC variables with the EL3783
Normal three-phase mains supply
The normal 3-phase low-voltage grids in Central Europe are characterized by the following interrelationship:
rated voltage is usually the effective voltage U
RMS
, e.g. 230 V
RMS
, as a star voltage between one of the three
live conductors (L1, L2 or L3) and neutral N.
Fig. 10: Voltages in three-phase mains supply of Central Europe
With a pure sinusoidal oscillation (unloaded grid) a maximum peak voltage (max. amplitude) of approx.
±325V
peak
to N is calculated from the then valid crest factor from
in the star voltage.
A phase-to-phase voltage of
(RMS) can be measured between the live
conductors.
RMS value specifications
RMS value (
rms
) specifications
All AC value specifications in this documentation such as RMS specifications (
rms
) refer to a
50/60 Hz 3-phase mains network with a sinusoidal waveform.
The EL3783 EtherCAT Terminal is a power monitoring terminal for state monitoring of a 3-phase AC voltage
system. The following properties are characteristic of the EL3783:
• 3 channels measure -737...+737 V through analog-to-digital converters in 16-bit resolution as
amplitude value
• 3 channels measure -9.2...+9.2 A through analog-to-digital converters in 16-bit resolution as amplitude
value
• all 6 analog input channels are measured simultaneously
• the EL3783 is an oversampling terminal and can therefore record not just 1, but up to 100 samples per
channel in each PLC/EtherCAT cycle. These are sent as a data packet to the controller via the cyclic
process data.
The minimum sampling time is 50 µs, corresponding to 20,000 samples/second.
