Omicron CPC 100 User Manual

CPC 100 V 3.20
Current Transformer - 7
Note: If the transformer’s knee point voltage is approximated or exceeded, due to the
transformer’s saturation the measurement results are not correct anymore. If the knee point is
extensively exceeded, the transformer can even be damaged.
Therefore, the knee point voltage should be known or measured beforehand.
Use the CTRogowski test card to measure a Rogowski coil’s ratio by injecting current into the
current-carrying conductor, and by measuring the induced voltage at the end of the Rogowski
coil windings.
A Rogowski coil’s induced voltage is proportional to the conductor current differentiated with
respect to time. Therefore, in order to acquire a direct equivalent of the conductor’s current, the
induced voltage needs to be integrated. In general, a Rogowski coil’s output signal is either lead
via an integrating amplifier or fed into an electronic protection relay with integrator. The
CTRogowski test card integrates the Rogowski coil’s output signal at the CPC 100’s V2 AC
input.
Disconnect the Rogowski coil’s output signal from the electronic protection relay, and plug it into
the CPC 100’s V2 AC input.
The CTRogowski test card measures the amplitude of the injected current Iprim and the
Rogowski coil’s output voltage Vsec, integrates this signal, and calculates the secondary
current I sec, its phase angle as well as the actual ratio and the deviation.
Secondary
inception voltage
Nominal primary current
Select to enter
primary voltage
instead of
measuring it
Nominal secondary current
Output
frequency
Ratio error
Measured
secondary
voltage
Primary voltage
measured on
V2 AC input
Polarity:
OK = phase I sec - phase I prim
= - 45 ° < 0 ° < + 45 °
NOTOK = all other cases
Ratio Iprim. / Isec.:
Isec act x (I prim nom/ I prim act)
and deviation in %
((Kn x Isec - Iprim)/Iprim) x 100 %
Select to stop test
automatically when
measurement is
done
Electronic protection relay with
integrator (e.g., 150 mV at
I nominal)
Shielded cable with twisted wires.
Shield connected to Rogowski coil.
Relay
CTRatio (with Voltage) CTRogowski

Omicron CPC 100 Specifications

General

Brand	Omicron
Model	CPC 100
Category	Test Equipment
Language	English