3-3
A.C. Power
Typical circuit connections for single-
phase ac watt meters and transducers are
given in figure 5. Calibration of these types
of devices requires use of both the voltage and
current outputs of the 1040C. Representative
calibration connection diagrams for these
types of devices are given in figure 6. The
1040C voltage output leads are connected to
the voltage terminals of the meter or
transducer, and the 1040C current output
leads are connected to the current input
terminals of the meter or transducer (figures
6a and 6c). If the meter or 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. Refer to figures 6b and 6d for
these connections. The user should then
select the proper operating frequency, either
60 Hz or 400 Hz. The "Power" key should be
pressed, which will place the 1040C into the
power mode, enabling both the voltage and
current outputs for simultaneous operation.
The "Voltage" key should then be pressed,
and the desired voltage entered using the
keypad, followed by "V". After this, the
"Current" key should be pressed and the
desired current entered using the keypad,
followed by "A". After this is completed,
pressing the "Operate" key will enable the
outputs, which will increase to the respective
values entered. An equal sign on the front
panel display indicates that the current and
voltage outputs, and the phase angle between
them, have stabilized at the proper values.
The calibration procedure for the meter or
transducer under test can then be performed.
The power value can be varied using the
control knob or the up/down arrows, but it is
important to note that it is only the current
that changes; the voltage remains constant.
For more complete instructions on operation
of the 1040C in the ac power mode, refer to
section 2.5.6 of the operation manual.
A.C. Frequency
Calibration of ac frequency is another
procedure that requires the use of only the
1040C voltage output. The connections are
the same as for the volt meter or transducer
(Figure 2). After connection, the frequency
range (i.e. 60Hz, 400Hz) is selected, then
"Voltage" is pressed. The operator then enters
the voltage value which is appropriate for the
device under test, followed by the voltage unit
key. Fine adjustment of the frequency can be
accomplished by first pressing the
"Frequency" key, then using the adjust knob
or up/down keys to select the value. A value
for frequency can also be entered via the
keyboard, by first pressing "Frequency",
entering the value, then pressing the "Hz" key.
When the "Operate" key is pressed, the
voltage output will be enabled and the
calibration procedure for the device under test
may be performed. For more complete
instructions on frequency operation of the
1040C, refer to section 2.5.8 of the operation
manual.
To Next Page
Loading...
Need help?
General