KYORITSU 2431 - Manual (Page 2)

4−2
AC current to measure may have harmonics or high frequency
components generated by such equipment as inverters. To eliminate
these superimposed components and measure only the fundamental
frequency of 50Hz or 60Hz, Model 2431 has a high-cut filter circuit,
which can be activated by setting the frequency selector switch to the
'50/60Hz' position.
The high-cut filter has a cut-off frequency of 100Hz and an attenuation
characteristics of approx. -24dB/octave. When the filter is disabled,
'WIDE' is shown on the display. Pressing the frequency selector switch
enables the filter, indicating '50/60Hz' on the display. Press the switch
again to exit the '50/60Hz' mode.
All renges at WIDE Position
All ranges at 50/60Hz Position
（ー24dB/oct）
０
−１０
−２０
４０ ５０ ６０ １００ ２００ ３００ ４００ ５００ １Ｋ ２Ｋ
５
１０
２０
３０
５０
１００
Freguency［ H z ］
Percentage（％） Attenuation
（dB）
Model 2431 Frequency characteristics is as shown below.
Fig.3
-24/octave means that the magnitude of a signal declines by a factor of
16 when its initial frequency doubles.
The frequency selector switch has the following two positions.
WIDE（40Hz -）：Covers a wide range of frequency band from mains
supply to high frequencies generated by such equipment as inverters.
50/60Hz（40 - Approx. 100Hz）：Filter out high frequency components
to restrict measurement in mains frequency band.
Recently there has been increased usage of power through inverters,
switching regulators, etc. When high frequency noise from such
appliances leaks or flows into the ground through capacitors not filtering
completely, the earth leakage breaker may trip. In such a case, the
instrument may not give current readings with the frequency selector
switch set to the 50/60Hz mode. Therefore, when in doubt as to the
presence of high frequencies or harmonics that affect AC leakage
current measurements, take current readings with the switch set to the
50/60Hz and WIDE modes respectively and then compare the results
obtained
4−3
（1）Push the Data Hold switch to freeze the reading. The 'H' symbol is
shown on the display, indicating that the instrument is in the Data
Hold mode.
（2） Push the switch again to exit the Data Hold mode.
4−4
In approx. 10 minutes after it is turned on, Model 2431 automatically
turns power off and the display goes off. To exit the power-off state,
turn the range switch to the OFF position, then back to any desired
range.
５．BATTERY REPLACEMENT
When the display blanks or symbol "BATT" appears in the left lower
corner of the display, replace the batteries.
Never replace the batteries while making measurement.
（1）Set the range switch to the OFF position.
（2）Press in the hole on the battery compartment cover with the tip of a
pointed object, then slide open the cover.
（3）Replace the two batteries with new ones, observing correct
polarity. Replacement batteries should be type LR-44 or SR-44.
＊
（4）Slide the battery compartment cover in place.
６．OPTIONAL ACCESORRIES
MODEL 8004 and 8008（Multi-Trans）
These Multi-Trans extend measurement capability of MODEL 2431,
enabling measurement of a current more than 200A and tests on a
large bus-bar or conductor.
These Multi-Trans cannot be used for leakage current measurement.
（1）Set the range switch of
MODEL 2431 to a desired
range.
（2）As shown in the figure on
the right, open the
transformer jaws of MODEL
2431 and close them over
the pickup coil of MODEL
8004 or 8008 Multi-Tran.
（3）Clamp the Multi-Tran onto
the bus-bar or conductor
under test.
（4）Take the reading on
MODEL 2431 and multiply
it by 10.
Transformer Jaws
Pickup Coil
Conductor
*Up to 2000A when used with MODEL 2431.
For more information, see the instruction manual for MODEL 8004 or
8008.
8004
8008
Maximum Conductor Size Range
60mm in diameter
100mm in diameter
0∼1000A AC
0∼3000A AC※
10：1
10：1
Model Multiplication Factor
’ 04―10 Printed in Japan
DISTRIBUTOR
92―1470A