Current Transformer
4 - 35
Measurements
Selecting the check box "Manual input" lets you enter the value for Vprim
manually, for example, when Vprim was measured with an external volt meter.
Vsec: actual output at the 2kV AC output that is injected to the CT’s
secondary side
Vprim:
measured voltage on CT’s primary side and phase angle
ϕ
relative to Vsec
Iout measured current from Vsec output
Ratio: ratio Iprim /Isec, here 200:5.0134
1
1. The ratio value 5.0134A is calculated as follows:
Vprim act x (Iprim nom / Vsec act); here: 1.2536V x (200A / 50.010V) = 5.0134A
and deviation of current ratio in %. Formula:
((Kn x Vprim - Vsec) / Vsec) x 100%
2
((200A / 5A * 1.2536V - 50.010V) / 50.010V) x 100% =
+0.268%
2. Kn = rated transformation value, here: 200A / 5A
Polarity: displays the status of the polarity
OK = phaseVprim - phaseVsec = -45° < 0° < 45°
NOT OK = all other cases
To Next Page
Loading...
