Appendix 2: Current Transformer - Ingeteam INGECON EMS Manager Manual De Instalacion Y Uso

Appendix 2: Current Transformer

Appendix 2: Current Transformer
Current transformer parameters for three-phase installations (A65+ wattmeter).
The parameters indicated below must be considered in order to select the correct current transformer:
Ip: Nominal primary current (A)
The nominal current on the primary must be greater than or equal to the maximum current per system phase.
Is: Nominal secondary current (A)
Nominal current value on the current transformer secondary.
The nominal current of the Wattmeter to be connected to the transformer secondary is In = 5 A and its maximum
current is Imax = 10 A.
To ensure the Wattmeter measures precisely, at least one current transformer with a nominal secondary current of
Is = 5 A must be used.
Ingeteam does not guarantee the precision and correct functioning of the strategy configured in the
INGECON EMS Manager when transformers with a nominal secondary current (Is) of less than 5 A
are used.
Transformers with a nominal secondary current that is higher than the maximum current of the
Wattmeter (i.e. 10 A) may not be used.
K : Transformation ratio (A)
N
Ratio between the nominal current of the primary and the nominal current of the secondary. This is expressed as a
fraction. Example: K = (150 A / 5 A).
N
Cl: Precision class
The precision class is the percentage current error limit when operating at nominal current.
Ingeteam requires a current transformer precision class of 0.5 (Cl 0.5).
Current transformers with a precision class that allows for current measurement with an error below that
established by precision class 0.5 are also accepted.
Sn: Precision power ( VA )
This parameter describes the capacity of the transformer to make the current run around the secondary through
a load, maintaining the precision class. The power consumed in the current transformer secondary must be
calculated in VA (bear in mind the sum of wiring and the A65+ Wattmeter in this calculation).
The standardised power closest to that calculated should be selected. The standardised power must be higher than
that calculated.
AAX2022IQM01_ - Installation and Operation Manual
Ip Ip
Sn
Is Is
A65+
Sc
Sw
Sn ≥ Sc + Sw
L1
L2
L3
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