Arbiter Systems 1040C User Manual

3-8
parallel and placed across the voltage output
of the 1040C. Again, current and potential
transformers are shown for reference.
Phasing of the elements is of great importance
for accuracy of the calibration. All current
elements should be wired the same way, and
all voltage elements should be in phase. The
only exception to this rule would be for 2 1/2
element transducers, which are sometimes
used in order to save the cost of one potential
transformer. The missing potential input is
accounted for mathematically, so during
calibration one of the current transformers
must be reversed, and special calculations
apply. When calibrating 2 1/2 element
transducers, the product documentation for
the device should be consulted for proper
procedures.
Phase Angle
Wiring connections for phase angle
transducers used in three-phase systems at
first glance may appear somewhat
unorthodox. Typically, a single voltage
element and a single current element are used.
The current element is placed in series with
one of the phases, or, if used, a current
transformer is placed around the conductor for
that phase. The voltage element is wired
between the remaining two phases, sometimes
employing a potential transformer. Refer to
figure 11a for a typical application circuit. If
the phase angle between the voltage and the
current in the circuit is zero, the net voltage
between the two measured phases (or the
output voltage of the potential transformer)
will be offset from the current measured in the
third phase by 90 degrees. The two input
signals are compared internally, and a dc
voltage corresponding to the phase angle is
output from the transducer.
Connections for use of a 1040C to
calibrate this type of phase angle transducer
are shown in figure 11b. The 1040C voltage
output leads are connected to the voltage
terminals of the transducer, and the 1040C
current output leads are connected to the
current input terminals of the meter or
transducer. If the transducer uses an external
current transformer, one of the current output
leads of the 1040C should be passed through
the center of the current transformer, and then
shorted to the other lead. If the meter or
transducer uses an external potential
transformer, then likewise it must be inserted
between the 1040C voltage output leads and
the input voltage leads of the unit under test.
The 1040C should first be configured to
operate in the ac power mode, and the
appropriate voltage and current values should
be selected. Next, a calibration phase angle
value must be entered, keeping in mind that
for indication of zero phase from the
transducer output, the input voltage must be
offset from the input current by 90 degrees
(whether this is a lead or lag condition
depends on the individual transducer
manufacturer. The calibration procedure for
the phase angle transducer can now be
performed. For more complete instructions
on operation of the 1040C for phase angle
calibrations, refer to section 2.5.1 of the
operation manual.
Power Factor
In order to accomplish power factor
indication, some transducer manufacturers
recommend using one of their phase angle
transducers and performing a mathematical
conversion on the output signal. This can be
done manually, using conversion tables
supplied by the manufacturer, or
automatically using a meter having cosine
scaling. If a phase angle transducer is
employed for this purpose, the connections
will be the same as those illustrated in figure
11.

Arbiter Systems 1040C Specifications

General

Brand	Arbiter Systems
Model	1040C
Category	Test Equipment
Language	English