Hi Marina,
The solution is to force the Y axis to display a custom range of values (in your case from 0 to 5) regardless of the min max provided by the series.
NChart chart = nChartControl1.Charts[0];
NBarSeries bar = new NBarSeries();
chart.Series.Add(bar);
bar.Values.AddRange(new double[] { 1, 3, 4, 2 });
NOrdinalScaleConfigurator scaleX = chart.Axis(StandardAxis.PrimaryX).ScaleConfigurator as NOrdinalScaleConfigurator;
scaleX.AutoLabels = false;
NStandardScaleConfigurator scaleY = chart.Axis(StandardAxis.PrimaryY).ScaleConfigurator as NStandardScaleConfigurator;
scaleY.AutoLabels = false;
scaleY.CustomLabels.Add(new NCustomValueLabel(1, "Very poor"));
scaleY.CustomLabels.Add(new NCustomValueLabel(2, "Poor"));
scaleY.CustomLabels.Add(new NCustomValueLabel(3, "Satisfactory"));
scaleY.CustomLabels.Add(new NCustomValueLabel(4, "Good"));
scaleY.CustomLabels.Add(new NCustomValueLabel(5, "Very good"));
chart.Axis(StandardAxis.PrimaryY).View = new NRangeAxisView(new NRange1DD(0, 5), true, true);
The last line makes the Y axis always show the values from 0 to 5. Hope this helps.
Best Regards,
Nevron Support Team