KMB SMY 133, Руководство по эксплуатации

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button Receive user can re-read the stored configuration from a device. This will effectively cancel all the local
modification in the application. Unwritten changes in configuration on each tab is signalized by an exclamation
sign. Buttons Save and Load provide a possibility to archive the actual settings to a file.
For correct operation an appropriate configuration of at least Installation and Time and Date tab is crucial.
2.5.1 Installation (fig.16)
ˆ
Nominal Frequency - defines the nominal network frequency measured at 50 or 60 Hz. It also influences,
how power quality indice are evaluated.
ˆ
Connection Mode - the way of connection of the instrument to the measured voltage — either direct voltage
measurement or via voltage transformers (usually in a HV network).
ˆ
Connection Type - type of measured network according to the actual connection - three-phase star, three-
phase delta or Aron connection. Supported connections schema are in fig. 16b and 16c for illustration.
ˆ
U
N OM
, P
N OM
(rated voltage and power) — correct configuration of these values influences relative values
used on display and in condition evaluation (alarms, PQ evaluation, IO, ENVIS data processing).
– U
N OM
is a nominal (primary) voltage of the measured network
– P
N OM
is a nominal power given by the system transformer or used protection device.
ˆ
VT Ratio, VTN Ratio - sets the conversion ratio of voltage inputs for Connection Mode: via VT measure-
ment. Must be set accordingly to the primary and secondary rating of the measuring voltage transformer
(transfer ratio). ’VTN’ designates the optional fourth voltage input, available with some Connection Types .
– nominal primary voltage: default value for ’via VT’ option is 22 000 V.
– nominal secondary voltage: default value is 100 V (other common values are 110, 120, 230V)
ˆ
CT Ratio, CTN Ratio - sets the conversion ratio of current input. ’CTN’ designates the fourth input,
usually a neutral wire.
– For standard instruments with X/5A and X/1A is specified as a ratio between primary and secondary
current. Default value is 100 A/5A resp. 1 A.
– For SMY 133 options X/100mA and X/20mA a nominal primary and nominal secondary current of
the supplied transformer is used. Default value is 100 A/100 mA resp. 20 mA.
–
ˆ
Multiplier U : this parameter is usually not necessary. Default value is 1. In special cases it can be used to
correct the ratio of measured voltage.
ˆ
Multiplier I - this parameter is usually not nescessry. Default value is 1.
– in case of direct current measurement (fig. 4) leave the Multiplier I in its default value:1.
– in case of indirect current measurements with nonstandard conversion ratio (multiple loops of mea-
sured wire through the measuring transformer etc) specify the new ratio as a fraction
5
to which you
need to multiply the original conversion ratio to get the real measured value of current.
5
If, for example, primary CT with ratio 100/5 is used, set multiplier to
100
5
= 20. Another example, when Multiplier I can
be used, is winding more than one loop of measured conductor through current transformer for sensitivity extension (and range
reduction). For example for 4 loops
Multiplier I should be set to
1
4
= 0 . 25.
16