Arbiter Systems 1040C User Manual

3-7
Using the 1040C for Calibrating Polyphase Devices
A.C. Voltage
Commercially available multi-phase
voltage transducers frequently consist of more
than one single-phase model from the
manufacturers product line, repackaged into a
common enclosure. In many cases, the
outputs remain separate and independent. The
procedure for calibration of these types of
transducers is virtually identical to that of the
single-phase voltage transducer. The three
elements can be connected in parallel across
the voltage output of the 1040C, as shown in
figure 7a, provided that the combined current
demand of the elements does not exceed the
burden capability of the 1040C (refer to table
1.2 in the operation manual). Multiple
voltmeters may also be connected to the
1040C in the same manner, as shown in figure
7b, with the same total current burden
restriction.
A.C. Current
Like their ac voltage counterparts,
commercially available multi-phase current
transducers frequently consist of more than
one single-phase model from the
manufacturers product line, repackaged into a
common enclosure. In many cases, the
outputs remain separate and independent. The
procedure for calibration of these types of
transducers is nearly identical to that of the
single-phase current transducer. The three
elements can be connected (in series) across
the current output leads of the 1040C, as
shown in figure 8a, provided that the
combined voltage drop across the elements
does not exceed the burden capability of the
1040C (refer to table 1.1 in the operation
manual). Multiple current meters may also be
connected to the 1040C in the same manner,
as shown in figure 8b, with the same total
voltage burden restriction.
A.C. Power
Power measurement in a three-phase,
four-wire system requires three complete watt
meters or watt transducers (each watt meter or
transducer consists of one current element and
one voltage element). Figure 9a shows a
typical connection diagram for measurements
of this type. A current sensing element is
placed in series with each of the three phases,
and a voltage sensing element is connected
between each of the phases and the neutral
wire. It is unnecessary to measure the neutral
current directly, since any current flowing in
the neutral conductor will be simultaneously
flowing in one or more of the phases and will
thus be measured.
Power measurement in a three-phase,
three-wire system requires two complete watt
meters or watt transducers. Figure 9b shows a
connection diagram for this type of
measurement. Again, the number of current
elements required is equal to one less than the
number of current-carrying conductors, since
any current in the non-instrumented conductor
must simultaneously be flowing in one or both
of the others. The voltage elements are
connected to the two phases having the
current elements, with the common point for
the voltage elements being the third phase.
Calibration of multi-element watt
transducers or meters can be accomplished
using the setup shown in figure 10. Basically,
all of the current elements would be
connected in series and placed across the
current output of the 1040C, and all of the
voltage elements would be connected in

Arbiter Systems 1040C Specifications

General

Brand	Arbiter Systems
Model	1040C
Category	Test Equipment
Language	English