CIRCUTOR QNA500 series - Manual (Page 31)

POWER QUALITY ANALYZER QNA500 8IO
QNA500 8IO Instruction manual 31 / 111
• Neutral Current Primary: The current transformer primary used to measure the neutral current
will be programmed.
• Primary VT * Primary CT ratios: Maximum primary value of VT multiplied by primary
value of CT must be lower than 2000000000
NOMINAL VALUES
• Nominal Voltage: Corresponds to the nominal voltage measured by the power quality analyzer.
In the case of the 3-wire configuration, the phase-phase voltage must be programmed (e.g. 400
V), and the phase-neutral voltage must be programmed for 4-wire configurations (e.g. 230 V).
When the measurement is recorded through the voltage transformers, the nominal voltage must
be programmed so that it is referred to the secondary (e.g. 63.5 V). This value is vital for the
correct recording of events.
• Nominal Current: Corresponds to the nominal current being measured by the analyzer, which
will be used to establish the maximum and minimum % to record disturbances. The default
value is 5 A. The value used to program measuring transformers is recommended.
• Nominal Frequency: Nominal frequency of the network being analyzed. This parameter is
required to calculate the effective value of the signal in top quality networks.
TYPE OF CONNECTION
• 3-wire / 4-wire: QNA500 8IO is prepared for an operation in installations with a neutral (4-
wires) or installations without a neutral (3-wires). The type of connection is defined at this point.
This is important, since the value programmed for this variable will be used to detect and record
voltage events. When programmed for 4-wires, all measurements will be taken from phase-
neutral, and when programmed for 3-wires, the reference values will be phase-phase.
MEASURING POINT
• Description: This field is only used for identification purposes by the user.
• Comments: This field is only used for information purposes by the user.