CPA Active power converter0 pages
CPA
Active power converter
GENERAL POINTS
The active power converter CPA measures the positive or negative power of a three-phase source with or without neutral.
Designed to operate with versions GPRII & GPRIII load commander for generating set applications, it is suitable for any application requiring a measurement and a conversion of power into
a +/-20mA signal.
OPERATING MODES
The CPA is suitable for any three-phase active power measurement and among others, when the measurement is far from
the treatment unit. With the GPR, the distance can be until one
kilometer using CRE recommended shielded cable.
Two adjustments are possible by the potentiometers zero and
gain. The zero potentiometer allows to adjust with precision the
zero power measurement to compensate the possible defects of
the installation. The gain potentiometer adapts the range of the
current output +/-20mA according with the maximum power of
the installation.
These 2 adjustments allow to operate in -12/+20mA with +4mA
for the power zero.
Thanks to its fast conversion, the CPA is particularly adapted for
power regulation and among others, for the control of generating
sets paralleled with the commercial power.
A24Z0 /1 /2 /3 /4 /5
CURRENTS
The CPA operates with current transformers of 5 Amps nominal
at the secondary. The gain potentiometer allows to adjust the
output signal at 20mA according with the nominal value at the
secondary of the current transformers.
The maximum current possible for the CPA is 6 Amperes. This
allows to measure 1,2 In (overload of 20%).
VOLTAGES
The CPA is available in 100, 230 et 400 volts AC between phases. Use voltage transformers if the voltage is higher
ACTIVE POWER CONVERSION
The CPA has a true active power measurement on each phase,
the result being the sum of the three:
P=U1xI1xCosPhi1+U2xI2xCosPhi2+U3xI3xCosPhi3.
The conversion time is lower than 200 milliseconds.
CURRENT OUTPUT
The ± 20mA current output of the power measurement is totally
isolated from the power circuit.