Beckhoff EL3413-0000, Documentation

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Product overview
EL34x3 25 Version: 4.4
2.3.6 Sign of the energy values
Name Index Variant Value AUX channel CoE
Sum (Ch 0) Channel ac-
cess (Ch
11/12/13) 0x90n0 0xF801
*)
Energy
difference 2 |E+| - |E-| ∑ |E+| - ∑ |E-| |E+| - |E-| N/A N/A
Energy
negative 5 -|E-| ∑ |E-| |E-| |E-| |E-|
Energy
positive 30 |E+| ∑ |E+| |E+| |E+| |E+|
Energy
difference
(automatically
saved) 32 |E+| - |E-| ∑ |E+| - ∑ |E-| |E+| - |E-| N/A N/A
Energy
negative
(automatically
saved) 35 -|E-| ∑ |E-| |E-| |E-| |E-|
Positive
energy
(automatically
saved) 31 |E+| |E+| |E+| |E+| |E+|
*) Access only possible from PLC
2.3.7 Frequency measurement
The EL34x3 can measure the frequency of the input signals at a voltage circuit (L1, L2 or L3).
Held frequency
The last frequency is displayed via indexes 46, 47 and 48, "Held Frequency", before one or more channels
report an "Undervoltage" or "Missing Zero Crossing" error.
The values may not represent the actual mains frequency (see also last note in chapter "
PM Inputs Channel
1/2/3 [
}
137] ").
2.4 Current transformer
In principle, the choice of current transformer for the EL34x3 is not critical. The internal resistance within the
current circuit of the EL34x3 is so small that it is negligible for the calculation of the total resistances of the
current loop. The transformers must be able to supply a secondary rated current in accordance with the set
measuring range. The primary rated current I
pn
can be selected arbitrarily. The common permissible overload
of 1.2 x I
pn
is no problem for the EL34x3, but may lead to small measuring inaccuracies.
Accuracy
Please note that the overall accuracy of the set-up consisting of EL34x3 and current transformers to a large
degree depends on the accuracy class of the transformers.
No approval as a billing meter
A set-up with a class 0.5 current transformer cannot be approved or authenticated. The EL34x3 is
not an approved billing meter according to the electricity meter standard (DIN 43 856).