KYORITSU 3128 User Manual

Rated Voltage

500V

1000V

2500V

5000V

10000V

12000V

Max value

500GΩ

1.00TΩ

2.50TΩ

5.00TΩ

35.0TΩ

35.0TΩ

Accuracy

400k to 50GΩ

±5%rdg±3dgt

800k to 100GΩ
±5%rdg±3dgt

2M to 250GΩ
±5%rdg±3dgt

4M to 500GΩ
±5%rdg±3dgt

8M to 1TΩ
±5%rdg±3dgt

8M to 1TΩ
±5%rdg±3dgt

50G to 500GΩ
±20%rdg
*Accuracy is
not guaranteed
with setting of
250V or less.

100G to 1TΩ
±20%rdg

250G to 2.5TΩ
±20%rdg

500G to 5TΩ
±20%rdg

1T to 10TΩ
±20%rdg

1T to 10TΩ
±20%rdg

10T to 35TΩ
Values are
displayed, but
accuracy isn’t
guaranteed.

10T to 35TΩ
Values are
displayed, but
accuracy isn’t
guaranteed.

Display Range

400k to 999k

1.00M to 9.99M

10.0M to 99.9M
100M to 999M

1.00G to 9.99G

10.0G to 99.9G
100G to 600G

800k to 999k

1.00M to 9.99M

10.0M to 99.9M
100M to 999M

1.00G to 9.99G

10.0G to 99.9G
100G to 999G

1.00T to 1.20T

2.00M to 9.99M

10.0M to 99.9M
100M to 999M

1.00G to 9.99G

10.0G to 99.9G
100G to 999G

1.00T to 3.00T

4.00M to 9.99M

10.0M to 99.9M
100M to 999M

1.00G to 9.99G

10.0G to 99.9G
100G to 999G

1.00T to 6.00T

8.00M to 9.99M

10.0M to 99.9M
100M to 999M

1.00G to 9.99G

10.0G to 99.9G
100G to 999G

1.00T to 9.99T

10.0T to 35.0T

8.00M to 9.99M

10.0M to 99.9M
100M to 999M

1.00G to 9.99G

10.0G to 99.9G
100G to 999G

1.00T to 9.99T

10.0T to 35.0T

Out-of-range
display

Upper limit

<400kΩ

<800kΩ

<2.00MΩ

<4.00MΩ

<8.00MΩ

<8.00MΩ

Lower limit

>600GΩ

>1.20TΩ

>3.00TΩ

>6.00TΩ

>35.0TΩ

>35.0TΩ

Short-circuit current

Max 5.0mA

Leakage current

0.01nA∼

Output current

1mA or more,

1.2mA or less
under a load of

0.5MΩ
*Should be
500V or more

1mA or more,

1.2mA or less
under a load of
1MΩ

1mA or more,

1.2mA or less
under a load of

2.5MΩ

1mA or more,

1.2mA or less
under a load of
5MΩ

0.15mA or
more, 0.25mA
or less under a
load of 10MΩ

0.15mA or
more, 0.25mA
or less under a
load of 12MΩ

Measuring Range

0.00nA∼ 2.40mA

Minimum resolution 0.01nA

(determined by resistance and voltage values)

Depending on the effective range

of insulation resistances

Cautionary statement/ Errata sheet

Followings are corrections and additional explanations for KEW3128 Instruction manual.
The contents of this sheet apply to the instrument with firmware ver.1.12 or later.

Specification tale for [Insulation Resistance Tester] on page 10 & 11 of the Instruction manual for KEW3128 is
modified as follows. The lower accuracy limit, display range and out-of-range display at each Voltage Range
are added.
[Insulation Resistance Tester]

Note: The Lower limit value within the Display Range is shown when the test leads are short-circuited and the

Upper limit value within the Display Range is shown when measured values exceeds the Display Range.

P12 Additional explanation to [Ammeter]

[Ammeter]

Condition

Current consumption

Measurement time

500V / 300kΩ

2100mA

or less

Approx

2 hours

1000V / 600kΩ

2500V / 2.4MΩ

5000V / 4.8MΩ

10000V / 20MΩ

12000V / 24MΩ

10kV/12kV Range

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

0.0001 0.001 0.01 0.1 1 10 100

Insulation Resistance (GΩ )

Output Voltage (V)

12kV

10kV

500V/1 000V/2500V/5000V Range

0

1,000

2,000

3,000

4,000

5,000

6,000

0.0001 0.001 0.01 0.1 1 10 100

Insulation Resistance (GΩ )

Output Voltage (V)

500V

1000V

2500V

5000V

P.11 Additional graph of “Resistance-Output voltage Characteristic” for each Voltage range

[Graph of Resistance-Output voltage Characteristic]

Rated current at 500V, 1000V, 2500V, 5000V Ranges : max 1mA or higher
Rated current at 10kV, 12kV Ranges : max 0.5mA
Above graphs show the relations between output voltages and measurement resistances.
* “Rated measurement current” described in the table at page 11 should be corrected to “Output current”.

P.15 Additional description about current consumption and battery life

 Continuous measurement: No limitation (IR measurement mode)

* recorded data and graph are max 90 min.
Max 90 min (SV measurement mode)
Max 60 min (PI/DAR/DD measurement mode)

 Max current consumption and measurement time while rated currents are maintained.

* Current consumption may exceed above values when low resistances, which influence the output of

rated currents, are measured.

* Measurement time (approx 4 hours) described at page 15 and the Measurement time in above table

are the periods that full-charged battery voltage drops to the lowest level.

* It is recommended to charge the battery with reference to “7.1 How to charge battery” described in the

manual before stating to use with the instrument since the battery voltage may be low due to
self-discharge.

P32 Additional explanation to “Setting of Measurement Period”

The smallest value of selectable period is 15 seconds.

P41 Additional explanation to “6.1.6 Filter Mode”

Filter 1 : It uses it to cut the exchange element more than industrial frequency (50/60Hz) when a high electric field

has been generated around the circuit under test.

Filter 2 : Five measured latest data are averaged.

Filter 3 : Filter 1 and Filter 2 are used at the same time.

P.41 Additional explanations to “6.1.7 Save data”

Logging data (REC file) is recorded and saved in 15 seconds later from the beginning of a measurement.
The data 15 seconds or earlier is shown as “--“. When viewing a graph on the LCD of the instrument, the
measured results for 15 seconds from the beginning of a measurement are displayed with a straight line.

* It is same in real-time measurements using the supplied software “KEW Windows”.
The measured value is saved in 15 seconds later from the beginning of a measurement and the data
15 seconds or earlier is shown as “--“.

Following is an example of the display to be shown on “KEW Windows”.

P.48 Additional sentences at “6.3.1 Setting Item”

At IR measurements, continuous measurements over 90 min are possible , however, the displayable area of
the recorded data, graph and analyzed data are 90 min of measured results. The later portions are displayed
with numbers only.

P. 49 Additional sentences at “6.4.2 How to measure PI”

Displayed Items

Details

Insulation Resistance

Measured insulation resistance value

PI Resistance at TIME1,2

PI Resistance value at TIME1 and TIME2

DAR Resistance at TIME1,2

DAR Resistance value at TIME1 and TIME2

PI

Polarization Index value

Pre-set Voltage

Pre-set output voltage value

Output Voltage

Voltage being output

Current value

Current value being measured

Capacitance

Capacitance measured at discharge

DAR

Dielectric Absorption Ratio

PI value

DAR Resistance

at TIME1,2

PI Resistance

at TIME1,2

Pre-set Voltage

Output Voltage

Capacitance

DAR value

Current value

Insulation

DAR Simultaneous display

DAR value is displayed during PI measurements and the measured results are being displayed.
TIME 1 and 2 values for DAR are the ones pre-set in the DAR mode. Refer to 6.5.2 How to measure DAR
and set the time for DAR.
In case that DAR TIME 2 value is higher than PI TIME 2 value, DAR value isn’t displayed on the LCD. A
measurement stop when the PI TIME 2 comes. PI value isn’t displayed in the DAR measurement mode.

P. 52 Amendments to the illustration and table at “6.4.3 Measured Result”

P. 61 Additional sentence at “6.7.2 Measured Setting Items”

In the SV measurement mode, measurements continue after the preset Step time (V5) comes and
automatically stop when 90 min pass.

P.70 Amendments to the description at “6.11.3 Auto-power-off Function”.

The instrument automatically turns off when approx 10 min pass after a measurement with Timer function
activated or 90 min of continuous measurement in SV mode completes.

Instruction Manual

High Voltage Digital Insulation Tester

KEW 3128

2 KEW3128

Contents KEW3128

Contents

Contents ････････････････････････････････････････････････････････････ 2

1. Safety Warnings ･･･････････････････････････････････････････････････4

2. Feature ･･･････････････････････････････････････････････････････････ 7

3. Specification ･･････････････････････････････････････････････････････ 9

4. Instrument Layout ････････････････････････････････････････････････ 16

 4. 1 FRONT VIEW ･･･････････････････

 4. 2 SIDE PANEL ･･････････････････････････････････････････････････18

 4. 3 TEST LEADS ･････････････････････････････････････････････････ 19

 4. 4 HARD CASE ･･････････････････････････････････････････････････19

5. Preparation for Measurement･･････････････････････････････････････20

 5. 1 CHECKING THE BATTERY VOLTAGE ･･･････････････････････････20

 5. 2 TEST LEAD CONNECTION･･･

6. Measurement ････････････････････････････････････････････････････21

 6. 1 BASIC OPERATION ･･･････････････････････････････････････････21

  6.1.1 How to start measurements ･･････････････････････････････････21

  6.1.2 Steps for Measurements ･････････････････････････････････････23

  6.1.3 Setting for Measurement ･････････････････････････････････････30

  6.1.4 Graph Ope

  6.1.5 Menu･･････････････････････････････････････････････････････37

  6.1.6 Filter Mode･････････････････････････････････････････････････41

  6.1.7 Save Data ･････････････････････････････････････････････････ 41

  6.1.8 Clock Setting ･･･････････････････････････････････････････････46

  6.1.9 Demo Mode ････････････････････････････････････････････････46

6. 2 INSULATION DIAGNOSIS TESTS ･･･････････････････････････････47

 6. 3

  6.3.1 Setting Item ････････････････････････････････････････････････ 48

  6.3.2 Measured Result ･･･････････････････････････････････････････48

 6. 4

  6.4.1 Polarization Index ･･･････････････････････････････････････････49

  6.4.2 How to measure PI･･････････････････････････････････････････49

IR MEASUREMENT ･･････････････････････････････････････48

PI MEASUREMENT (POLARIZATION INDEX) ･･･････････････49

ration ････････････････････････････････････････････33

･･････････････････････････････16

･･････････････････････････････････20

KEW3128 3

KEW3128 Contents

  6.4.3 Measured Result ･･･････････････････････････････････････････52

 6. 5

DAR MEASUREMENT (DIELECTRIC ABSORPTION RATIO) ･53

  6.5.1 Dielectric Absorption Ratio ･･･････････････････････････････････53

  6.5.2 How to measure DAR ･･･････････････････････････････････････ 54

  6.5.3 Measured Result ･･･････････････････････････････････････････56

 6. 6

DD MEASUREMENT (DIELECTRIC DISCHARGE) ･･･････････57

  6.6.1 Dielectric Discharge ･････････････････････････････････････････57

  6.6.2 How to measure DD･････････････････････････････････････････58

  6.6.3 Measured Result ･･･････････････････････････････････････････60

 6. 7

SV MEASUREMENT (STEP VOLTAGE) ････････････････････61

  6.7.1 Step Voltage ･･･････････････････････････････････････････････61

  6.7.2 Measurement Setting Items ･･････････････････････････････････61

  6.7.3 Measured Result ･･･････････････････････････････････････････63

 6. 8 MEASUREMENT SCREEN ･････････････････････････････････････64

 6. 9 CAPACITANCE MEASUREMENT ･･･････････････････････････････ 67

  6.9.1 Mea

 6. 10

surement Screen ･･･････････････････････････････････････67

VOLTAGE MEASUREMENT ･･････････････････････････････68

  6.10.1 Measurement Screen ･･････････････････････････････････････ 68

 6. 11 OTHER FUNCTIONS ･････････････････････････････････････････ 69

  6.11.1 Use of Guard Terminal ･･････････････････････････････････････ 69

  6.11.2 Backlight Function ･････････････････････････････････････････70

  6.11.3 Auto-power-off function ･････････････････････････････････････7

7. Battery Charging and Replacement ････････････････････････････････71

 7. 1 HOW TO CHARGE BATTERY ･･････････････････････････････････71

 7. 2 HOW TO REPLACE BATTERY ･･････････････････････････････････72

8. Communication Function/ Supplied Software ･･･････････････････････74

 8. 1 HOW TO INSTALL THE SOFTWARE ････････････････････････････ 75

 8. 2 HOW TO START KEW WINDOWS FOR KEW3128 ･･････････････79

9. Ac

cessories ･･････････････････････････････････････････････････････80

 9. 1 METAL PARTS FOR LINE PROBE, AND REPLACEMENT ･････････80

10.Disposing the Product ･･･････････････････････････････････････････81

0

4 KEW3128

1. Safety Warnings KEW3128

1. Safety Warnings

○

This instrument has been designed, manufactured and tested according to IEC
61010: Safety requirements for Electronic Measuring apparatus, and delivered
in the best condition after passing quality control tests. This instruction manual
contains warnings and safety rules which have to be observed by the user to ensure
safe operation of the instrument and to maintain it in safe condition. Therefore,
read through these operating instructions before using the instrument.

# WARNING

● This instrument outputs high voltages. Read through and understand the
instructions contained in this manual before using the instrument.

● Keep the manual at hand to enable quick reference whenever necessary.

● The instrument is to be used only in its intended applications.

● Understand and follow all the safety instructions contained in the manual.

It is essential that the above instructions are adhered to.
Failure to follow the above instructions may cause injury, instrument damage
and/or damage to equipment under test.

○ The symbol # indicated on the instrument, means that the user must refer to

the related parts in the manual for safe operation of the instrument. It is essential

to read the instructions wherever the # symbol appears in the manual.

# DANGER : is reserved for conditions and actions that are likely to cause

serious or fatal injury.

# WARNING : is reserved for conditions and actions that can cause serious

or fatal injury.

# CAUTION : is reserved for conditions and actions that can cause injury

or instrument damage.

KEW3128 5

KEW3128 1. Safety Warnings

# DANGER

● Put a pair of insulated gloves and use this instrument.

● Never make measurement on a circuit in which the electrical potential

exceeds AC/DC600V.

● Do not attempt to make measurement in the presence of flammable
gasses. Otherwise, the use of the instrument may cause sparking, which
can lead to an explosion.

● Never attempt to use the instrument if its surface or your hand are wet.

● Be careful not to short-circuit the power line with the metal part of the test

leads when measuring voltage. It may cause personal injury.

● Do not exceed the maximum allowable input of any measuring range.

● Do not press the Test Button with test leads connected to the instrument.

● Never open the Battery Compartment Cover while making measurement.

● Do not touch the circuit under test when measuring insulation resistance or

right after a measurement. You may get an electric shock by a test voltage.

● Stop a measurement if contamination or carbonization which may impair
insulation characteristics is found on the test leads or around the terminals.

● Do not repeat short-circuiting/ opening of test leads intentionally during
insulation resistance measurements. Otherwise, measurements may be
ceased or LCD may become blank due to a malfunction of the instrument.
Aerial discharges occur at the tips of test leads when short-circuiting and
opening the test leads; excessive discharges may impair the performance
of the instrument.

# WARNIG

● Never attempt to make any measurement if any abnormal conditions are
noted, such as broken case and exposed metal parts.

● Do not rotate the Range Switch with the test leads connected to the equipment
under test.

●

Do not install substitute parts or make any modification to the instrument. Return
the instrument to Kyoritsu or your distributor for repair or re-calibration.

● Do not try to replace battery if the surface of the instrument is wet.

● Be sure to insert the plug into the terminal firmly when using test leads.

● Make sure to power off the instrument when opening the Battery Compartment

Cover for battery replacement.

1. Safety Warnings KEW3128

# CAUTION

● Always make sure to set the Range Switch to the appropriate position
before making measurement.

● Be sure to set the Range Switch to the OFF position after use and
remove the test leads. When the instrument will not be in use for a long
period, place it in storage after removing the battery. Instructions how
to remove a battery are described at Clause 7. Bat
replacement (=>P.71).

● Do not expose the instrument to the direct sun, high temperature and
humidity or dewfall.

● Use a cloth dipped in water or neutral detergent for cleaning the instrument.
Do not use abrasives or solvents.

● When this instrument is wet, please store it after it dries.

● Remove a battery from the instrument and pack it carefully at the time of

transportation.

tery Charging and

Symbol








#

CAT. Ⅳ

6 KEW3128

Danger of possible electric shock

Instrument with double or reinforced insulation

DC

AC

Earth terminal

Must refer to the Instruction Manual to protect humans and devices

The circuit from the service drop to the service entrance, and to the
power meter and primary overcurrent protection device (distribution
panel)

KEW3128 2. Feature

2. Feature

  KEW3128 is a digital high voltage insulation resistance tester with 6-range:

500V, 1000V, 2500V, 5000V, 10000V and 12000V, and can measure up
to 35TΩ. Fine adjustment of voltage setting at each Range is available.
Measured results can be saved in the internal memory; they can be transferred
to a PC via a special USB cord. Measuring data can also be transferred to a
PC in real-time.

● Designed to meet following safety standards:
   IEC 61010-1 CAT.IV 600V

● Insulation Resistance Measurement
   Test Voltage 12kV (max), Resistance 35TΩ (max),
   Short-Circuit Current 5mA (max)

● Insulation Diagnosis Tests
   Values of Polarization Index (PI), Dielectric Absorption Ratio (DAR) and

Dielectric Discharge (DD) are displayed automatically, and measurements
of Step Voltage (SV), Leakage Current and Capacitance can be performed.

   * Further details of Insulation Diagnosis Test is described in clause

6. 2 (=>P.47).

● Saving the Measured Data
   The internal memory can store 32 files (max).
   Use of Print Screen Function enables save of screenshots.

● Dual Power Supply
   Lead storage battery (12V, 5Ah) should be used for KEW3128. In the

event of interruption, while operating with AC power supply, power to the

instrument is automatically restored by the battery in the instrument.

KEW3128 7

2. Feature KEW3128

 ● Large Display

   5.7-inch (320 x 240 dots)

● Graph Display
   Variations in insulation resistances and leakage currents under

measurements are displayed as graphs.

● Application
   Data in the internal memory or measuring in real-time can be transferred to

a PC via a special USB adapter. The supplied software facilitates setting of
the instrument and data analysis.

 ● Live Circ

uit Warning

   LIVE circuit warning symbols plus audible warning

● Auto Discharge Function
   When insulation resistance like a capacitive load is measured, electric

charges stored in capacitive circuits are automatically discharged after
measuring. Discharge can be checked with a voltage monitor.

● Backlight Function
   Backlight function to facilitate working at dimly illuminated location or at

nighttime work.

● Auto-Power-Off Function
   To prevent the instrument being left powered on and conserve battery

power, the instrument automatically turns off approx. 10 min after the last
switch operation.

● Filter Function
   KEW3128 provides 3 kinds of Filter functions to alleviate fluctuations in

readings. Details of Filter function are described at 6.1.6 Filter Mode

   (=> P.40).

8 KEW3128

KEW3128 3. Specification

3. Specification

● Applicable Standards:
   IEC61010-1 CAT.IV 600V Pollution Degree2
   IEC61010-031 For Hand-held Probe Assemblies
   IEC61326 EMC Standard for electrical equipment for

measurement, control and laboratory use

IEC60529 IP64 （with the Bottom Case closed）
   CISPR22, 24

KEW3128 9

10 KEW3128

3. Specification KEW3128

 ● Measuring Range and Accuracy （under 23±5ºC and 45 – 75%RH）

【Insulation Resistance Tester】

Rated Voltage 500V 1000V

Max value 500GΩ 1TΩ

0~50GΩ

±5%±3dgt

Accuracy

50G~500GΩ

±20%

* Accuracy

is not
guaranteed
with setting

of 250V

or less.

Short-circuit

current

Rated

measurement

current

1mA or more, 1.2mA

or less under a load of

0.5MΩ

* Should be 500V or more

Max 5.0mA

or less under a load of

Rated Voltage 2500V 5000V

Max value 2.5TΩ 5TΩ

0~250GΩ

Accuracy

±5%±3dgt

250G~2.5TΩ±20% 500G~5TΩ±20%

Short-circuit

current

Max 5.0mA

0~100GΩ
±5%±3dgt

100G~1TΩ±20%

1mA or more, 1.2mA

1MΩ

0~500GΩ
±5%±3dgt

Rated

measurement

current

1mA or more, 1.2mA or

less under a load of

2.5MΩ

1mA or more, 1.2mA or

less under a load

of 5MΩ

KEW3128 11

KEW3128 3. Specification

Rated Voltage 10000V 12000V

Max value 35TΩ 35TΩ

Accuracy

Short-circuit

current

Rated

measurement

current

0~1TΩ

±5%±3dgt
1T~10TΩ

±20%

10T~35T

Values are displayed, but

accuracy isnt guaranteed

Max 5.0mA

0.15mA or more, 0.25mA
or less under a load of

10MΩ

Values are displayed, but

accuracy isnt guaranteed

0.15mA or more, 0.25mA
or less under a load of

0~1TΩ

±5%±3dgt
1T~10TΩ

±20%

10T~35T

12MΩ

【Output Voltage】

Rated Voltage 500V 1000V

Monitor Accuracy ±10%±20V ±10%±20V

Output Accuracy 0~+20% 0~+10%

Selectable Range

50~600V

(in steps of 5V)

610~1200V

(in steps of 10V)

Rated Voltage 2500V 5000V

Monitor Accuracy ±10%±20V ±10%±20V

Output Accuracy 0~+10% 0~+10%

Selectable Range

1225~3000V

(in steps of 25V)

3050~6000V

(in steps of 50V)

Rated Voltage 10000V 12000V

Monitor Accuracy ±10%±20V ±10%±20V

Output Accuracy -5~+5% -5~+5%

Selectable Range

6100~10000V

(in steps of 100V)

10100~12000V

(in steps of 100V)

 Incorrect readings are displayed when external AC voltages are applied.

12 KEW3128

3. Specification KEW3128

【Volt Meter】

Range Voltage Test

Measuring Range

DC Voltage AC Voltage

±30~±600V 30~600V(50/60Hz)

Accuracy ±2%rdg±3dgt

【Frequency】

Range Voltage Test

Measuring Range 45.0 ~ 65.0Hz

Accuracy ±0.2Hz

【Ammeter】

Measuring Range

0.0nA ~ 2.40mA
(determined by

resistance and voltage

values)

Depending on the

effective range of

insulation resistances

【Capacity Meter】

Range 500V ~ 5000V Range 10000V / 12000V Range

Accuracy

5.0nF ~ 50.0μF 5.0nF ~ 1.0μF
±5%rdg±5dgt

 * Measurements of capacitance of 0.5μ or more shouldnt be repeated at

10000V/ 12000V Ranges in a short time. (Rough guide: 5 times/ hour)

 * A message Noise Error may be displayed on the LCD and a measurement

may be ceased at 10000/12000V Ranges. In this case, select a lower Voltage
Range and test again.

【Calculated Value】

PI,DAR,DD

Measurement Mode PI DAR DD

Display Range 0.00 ~ 999 0.00 ~ 999 0.00 ~ 999

Computational error ±2dgt ±2dgt ±2dgt

● Electromagnetic compatibility (IEC61000-4-3)
   Radio-frequency electromagnetic field

= 10V/m : 20times of the specified accuracy

KEW3128 13

KEW3128 3. Specification

● Operating system Dual integration

● Display

320 x 240 dots, 5.7-inch
Monochrome Display

● Low battery warning Battery mark display (in 4 levels)

● Response time approx 30 sec in a range of ±5% of accuracy
approx 60 sec in a range of ±20% of
accuracy (Response time becomes slower
when output voltage becomes lower.)

● Auto-power-off

Power-off function operates when 10 min
pass without any key operatio

n.

● Altitude 2000m or less

● Temperature & humidity

range(guaranteed accuracy)

● Operating temperature &

humidity range

23ºC±5ºC/Relative humidity 85% or less
(no condensation)

-10ºC~50ºC/Relative humidity 85% or less
(when operating with an external power
supply, no condensation)
0ºC~40ºC/Relative humidity 85% or less
(when operating with battery, no condensation)

● Storage temperature &

humidity range

-20ºC~60ºC/Relative humidity 75% or less
(no condensation)

● Overload protection AC720V/10 sec.

● Withstand voltage

AC8770V : between line terminal and
enclosure /5sec (50/60Hz)
AC6880V : between the measuring
terminal and enclosure /5sec (50/60Hz)
AC2330V : between the power connector
and enclosure /5sec (50/60Hz)

● Insulation resistance 1000MΩ or more/DC1000Ｖ

● Dimension

(between electrical circuit and enclosure
330(L)×410(W)×180(D)mm

)

(Instrument and Hard case )

● Weight

approx 9kg (including battery)
(Instrument and Hard case )

● Power source

Rechargeable Lead storage battery
( PXL-12050:12V 5Ah), AC Power supply
(100V ~ 240V, 50 / 60Hz)

14 KEW3128

3. Specification KEW3128

 ● Current Consumption (representative values at 12V of battery voltage)

Range 500V 1000V

Short-circuiting the output 2650mA 2300mA
Short-circuiting the output

of rated current

1350mA/0.5MΩ 1500mA/1MΩ

Opening the output 210mA 220mA

Range 2500V 5000V

Short-circuiting the output 1700mA 1600mA
Short-circuiting the output

of rated current

1650mA/2.5MΩ 2000mA/5MΩ

Opening the output 280mA 380mA

Range 10000V 12000V

Short-circuiting the output 1550mA 1550mA
Short-circuiting the output

of rated current

500mA/10MΩ 540mA/12MΩ

Opening the output 570mA 650mA

Range Voltage Test

Measuring voltages 210mA

Range All Ranges

On Stand-by 210mA

Backlight is On Increased by 80mA

KEW3128 15

KEW3128 3. Specification

● Measurement time approx 4 hours (continuous use)

Applying a load of 100MΩ at the Insulation
resistance 12000V Range

● Accessories Line Probe (MODEL7226)

Line Probe with Alligator Clip (MODEL7227)
Earth Cord (MODEL7224)
Guard Cord (MODEL7225)
Communication Adapter
(MODEL8212 USB)
PC Software
Straight Type Metal Parts (MODEL8029)
Power Cord (MODEL7170)
Instruction Manual

16 KEW3128

4. Instrument Layout KEW3128

 4. Instrument Layout

 4. 1 Front View

KEW3128 17

KEW3128 4. Instrument Layout

Keys

Keys Details

Print Screen/

Backlight

ESC

ENTER

UP/DOWN

TEST

Range Switch

Shuttle Switch

Key

Key

Key

Key

Button

Short press : Turn on/ off the LCD Backlight
Long press : Save the displayed screen as a

(1sec or longer) BMP (bitmap) file.

Cancel a process, or return to the previous screen.

Confirm entries, or move to the next screen.

Move a cursor or alter setting values.

Start measurements.

Power on/off the instrument, or select a
Measurement Range.

Move a cursor or alter setting values.

18 KEW3128

4. Instrument Layout KEW3128

バックライト

Power Connector

ESCキー

Battery Cover

ENTERキー

USB Connector

Connectors

4. 2  Side Panel

KEW3128 19

KEW3128 4. Instrument Layout

Line Probe (red)

Earth Cord (Black)

Guard Cord (Green)

Line Probe
w/Alligator Clip (red)

Regulating valve

4. 3  Test Leads

Depending on usage, either Line Probe or Line Probe with Alligator Clip is
connected to the Line terminal.

4. 4  Hard Case

Regulating valve is to balance the air pressure in the Case hermetically sealed
and external atmosphere for easy opening/closing of Case lid.
Do not force to turn it or remove it.

5. Preparation for Measurement KEW3128

 5. Preparation for Measurement

 5. 1 Checking the battery voltage

   Set the Range Switch to any position other than OFF without connecting

the Power Cord to the Power Connector.

   When the Battery Mark shown at the upper right on the LCD is last 1 level

( ), the battery is almost exhausted. Replace or recharge battery
to continue measurements. The instrument operates properly even if
under such a low battery, and such a low battery status may not affect the
accuracy.

   When the Battery Mark is vacant ( ), the battery voltage is below the

lower limit of the operating voltage. So the accuracy cannot be guaranteed.

   No measurement can be performed even the TEST Button is pressed

down. Refer to Battery Charge and Replacement (=>P.71) and charge or

replace battery.

 5. 2 Test Lead Connection

Insert the test lead firmly to the Connector Terminal on the instrument.
   Connect the Line Probe (red) or Line Probe with Alligator clip (red) to

the Line Terminal, Earth Cord(black) to the Earth Terminal and Guard
Cord(green) to Guard Terminal. No need to connect Guard Cord when
establishing a guard is not necessary.
Refer toHow to use Guard Terminal(=>P.69) in this manual for further details.

# DANGER

● If the TEST Button is pressed while the Range Switch is at a Range other
than OFF, high voltages may applied to the test leads and you may get
an electric shock.

● Do not connect the Earth Cord (black) nor Guard Cord (green) to the Line
Terminal.

Carefully read through 1. Safety Warnings (P.4) in this manual.

20 KEW3128

KEW3128 6. Measurement

 6. Measurement

 6. 1 Basic Operation

  6.1.1 How to start measurements

Start-up Screen

    Setting the Range Switch to any position other than the OFF position

powers on the instrument. Setting the Switch to the OFF position powers
off the instrument.

    Following Start-up Screen with Model name and Version info is displayed

when powering on the instrument. Then KEW logo will appear.

* Pressing the Enter Key skips the opening screen.

    The Mode Selection Screen app

purchase.

    The instrument remembers the previous selected mode, and starts with

the mode next time it is powered on.

KEW3128 21

ears at the initial operation after

22 KEW3128

6. Measurement KEW3128

How to select a Measurement Mode

    A long press (1 sec or more) of the ESC Key displays the Mode Selection

Screen.

    Measurement modes which are selectable on the Model Selection Screen

are mentioned at Insulation Diagnosis test (=>P.47).

Move the cursor with the UP/ DOWN Key
or Shuttle Switch, and confirm the mode
with the ENTER Key.
Then a process from making settings to a
start of measurement is displayed at the
bottom of the LCD. Measurement Modes
can be switched directly from the Menu.
(=>P.37 Menu)

KEW3128 23

KEW3128 6. Measurement

  6.1.2 Steps for Measurements

Insulation Resistance Measurement

   ①  Check the voltage which can be applied to the circuit under test,

and set the Range Switch to any desired Voltage Range.

   ②  Select the IR (Insulation Resistance) on the Mode Selection

Screen, and press the ENTER Key.

    The instrument gets started with the previously selected mode, and enters

into the stand-by mode.

   ③ Set a voltage value, and confirm it with the ENTER Key.

   ④  Confirmation Screen is displayed. Press the ENTER Key and

confirm the value.

24 KEW3128

6. Measurement KEW3128

LINE

   ⑤ 

The instrument enters into stand-by mode when settings are made.

   ⑥  Connect the Earth Cord (black) to the Earth Terminal of the

circuit under test.

    ⑦  Put the tip of the Line Probe (red) to the circuit under test. Then

press the Test Button. The buzzer sounds intermittently during a
measurement.

     Press and turn the Test Button clockwise to lock the Button for making

measurements continuously.

     The sound of buzzer when a Voltage Range is set to 12kV is special to

give warnings that high voltages more than 10kV is output.

KEW3128 25

KEW3128 6. Measurement

   ⑧ The measured value will be displayed on the LCD.

    ⑨   Release the Button to stop the measurement. Then the measured

results will be displayed on the LCD.

      Turn the locked Test Button counterclockwise and unlock the Button.

    ⑩   This instrument has an auto-discharge function. With the test

leads connected to the circuit under test, release the Test button
to discharge capacitance in t

he circuit after test.

Confirm that the readings on the Voltage monitor becomes 0V.
     *

When the test leads are disconnected from the measured object
during a discharge, keep the same connection and connect the
test leads to the measured object again and continue a discharge.
Attention should be paid when connecting the test leads and the
measured object again so as not to cause aerial discharges between
them for a long period. In this case, a longer discharge period is
required because the internal discharge circuit doesnt work.

    ⑪  Set the Range Switch toOFFposition, and remove the test

leads from the device under test.

    Next measurement may not be started when the Test Button is pressed

right after when above step 10 is done. In this case, release the Test

Button and wait for a few seconds, and then press the Test Button.

    Refer to  IR Measurement (=>P.48) and subsequent pages about

the further details of items displayed at each Measurement mode.

26 KEW3128

6. Measurement KEW3128

# DANGER

● Do not touch the circuit under test just after finishing a measurement. The
charged potentials may cause electrical shock hazard.

● Do not touch the circuit under test and also not to remove the test leads
until a discharge completes.

● Check with a High Voltage Detector that there is no electrical charge exists
on the circuit under test.

● Be sure to put on a pair of insulated gloves fo

● Be extremely careful not to get electric shock during insulation resistance

measurements and the Test Button is being pressed as high voltage is
present on the tip of test leads and on the circuit under test continuously.

● Do not make measurement with the Battery Cover removed.

● Do not make measurement when thunder rumbling.

r high voltage.

# CAUTION

● When the live circuit warning is indicated or the warning buzzer sounds,
measurements cannot be made even if the Test Button is pressed.

    To check the insulation of electric equipments or electric circuits, measure

their insulation resistances with this instrument. Be sure to check the
voltage which can be applied to the equipment under test before making
a measurement.

Measurements automatically stop, when battery voltage becomes too low
to ensure accuracy of readings, while the instrument is operating with a
battery. In this case, the instrument performs auto-discharge and displays
warning for low battery voltage as shown below. Then LCD becomes blank.

KEW3128 27

KEW3128 6. Measurement

A

  Note:

  * Insulation resistance values of the equipment under test may not be

stable, and the readings on the LCD may be unstable.

  * Oscillation sound may be heard during insulation resistance measurement,

but it is not malfunction.

* It takes time to measure a capacitive load.
  * Measurements, right after a measurement complete, may not get started

even the Test Button is pressed. In such a

case, press the Button in

several seconds later.

  * At insulation resistance measurement, positive (+) voltage is outputted

from the Earth terminal and negative (-) voltage is outputted from the Line
terminal.

   Connect the Earth Cord to the Earth (ground) Terminal. It is recommended

to connect the positive(+) pole to the earth side when measuring insulation
resistance against the ground or when a part of the equipment under test
is earthed. With this connection, smaller measured value can be obtained
comparing with other way round.

  * Do not extend and use the test leads; it may affect on measurement

accuracy or impair the safety of this instrument.

  * When measuring high resistance higher than 1TΩ, the Part A of the Line

Probe indicated in the below illustration shouldnt be touched with the
things other than the measured object. In case that such a contact is
unavoidable, use something with high insulation resistance like Teflon or
foamed polystyrene, as a cushion.

   * When making measurements without connecting the test leads to

anything to be tested, an over-range indication , e.g. >35.0TΩ (at 10kV
or 12kV Range), may not be displayed.

   It is likely caused in high humidity environment due to currents leaked at

unexpected points other than the measured objects due to applying high
voltages.

   * Proper measurements cannot be made due to influences of variations in

strong magnetic fields or noises caused at discharging energies stored in

28 KEW3128

6. Measurement KEW3128

capacitors or something like this when short-circuiting/ opening the Line –
Earth (Guard) of the test lead during an insulation resistance measurement
is repeated. In this case, Noise Error is displayed on the LCD and further
measurement is ceased. Placing the test leads onto the LCD tends to
cause this phenomenon (indications may be all cleared) ; so do not place
the test leads onto the LCD.

  When LCD becomes blank, rotate the Range Switch to the OFF position,

and then set it to any desirable Voltage Range.

  * When measuring low resistances (in case that currents larger than

the rated current is output) for a long time, the measured object or
the instrument may become heat and dangerous due to high energy
consumption. So this instrument automatically reduce the output voltages
when measuring low resistances. A message Stop measuring is
displayed on the LCD, when low resistances are measured for a long time,
and measurements are stopped.

   Temperature inside the instrument is high when Stop measuring is

displayed and measurements are ceased. In this case, please wait at least
30 min to make further measurements.

  * The Voltage monitor may indicate 10V to 200V instead of 0V when short-

circuiting the Line Probe and Earth Cord when voltages are output. In this
case, voltages applied to the resistors mounted in the internal measuring
circuit are included and displayed on the LCD.

KEW3128 29

KEW3128 6. Measurement

Check of Power Interruption（Voltage Measurements）

# DANGER

● Do not make measurement on a circuit above AC/DC600V(voltage to earth)
to avoid possible electric shock.Do not make a measurement, even if a line
voltage is 600V or less, when a voltage to earth is over 600V.

● When testing installation that has a large current capacity, such as a power
line, be sure to make measurements on the secondary side of a circuit
breaker in order to avoid possible hazard to the user.

● Extra precaution shall be taken to minimize the possibility of shorting the
power line with the metal tip of test lead at voltage measurement. It may
cause personal injury.

● Do not make measurement with the Battery Cover removed.

    Voltage can be measured by selecting the Vtest (Voltage) on the Mode

selection screen. (=>P.22 How to select a Measurement Mode) No need
to press the Test Button to start a measurement.

    This instrument is equipped with AC/DC auto-detect circuit, and can

measure DC voltages. At a DC voltage measurement, when applying
positive voltage to the Line Probe (red), positive values are displayed on
the LCD.

   ①  Turn off the Circuit Breaker of

the circuit under test.

  ② 

  ③ 

   Refer to Voltage Measurement (=>P.68) for further details on the

Connect the Earth Cord (black) to
the earth side of the circuit under
test and the Line Probe (red) to
the line side respectively.
The voltage displayed on the LCD
shall be Lo V. If not, voltages

of 30V or more is applied on
the circuit under test. Check
the circuit under test again and
confirm that the Circuit Breaker is turned off.

indications on the LCD.

30 KEW3128

6. Measurement KEW3128

  6.1.3 Setting for Measurement

    Select a mode at Measurement Mode Selection Screen, and make

settings for measurements.

Setting items are displayed on the LCD one
by one.
Use the UP/DOWN Key and Shuttle

Switch and alter the values, and press the
ENTER Key to confirm the entry and move
to the next setting item. Pressing the ESC
Key returns to the previous item. All the

set items are displayed on the LCD once
settings are done. Press the ENTER Key

at a Confirmation Screen to get the instrument entered into a stand-by mode.
A process from making the setting to a start of measurement is displayed
at the bottom of the LCD with the corresponding stage mark flashing. The
Measurement Setting Screen is also accessible from the Menu. (=>P.37 Menu)

KEW3128 31

KEW3128 6. Measurement

Setting of Output Voltage

    Output voltage can be selected with the Range Switch first, and then fine

adjusted with the Cursor Keys. Selected voltage values cannot be altered
while making measurements or outputting voltages.

    The table below shows the selectable range of voltages and step values

at each Measurement Range.

Range Step Min Max

500V 5V 50V 600V

1000V 10V 610V 1200V

2500V 25V 1225V 3000V

5000V 50V 3050V 6000V

10000V 100V 6100V 10000V

12000V 100V 10100V 12000V

32 KEW3128

6. Measurement KEW3128

Setting of Measurement Period

    TIME1 & 2 for PI/DAR Measurements, TIME for DD Measurements and

Step time for SV Measurements can be altered respectively.

The table below shows the step values for each selectable period.

Selectable period Step

1 sec – 1 min 1 sec

1 min – 10 min 30 sec

10 min – 60 min 1 min

KEW3128 33

KEW3128 6. Measurement

  6.1.4 Graph Operation

    Selecting the  Time Axis ZOOM or  Measured Value Axis

ZOOM from the ENTER Menu (=>P.37) on the Graph Display Screen
enters into Graph ZOOM Mode. In this mode, zooming and scrolling of
graphs are available. A short press (within 1 sec) of the ESC Key in the

Graph ZOOM Mode quits the Graph ZOOM Mode and returns to a normal
Graph Display Screen. The instrument keeps the zoomed percentage and
the scrolled condition.

Zooming in/ out of graphs

    Use the UP Key to zoom in the graph and the DOWN Key to zoom out.

The Voltage Axis at SV measurements is fixed and cannot be changed.

34 KEW3128

6. Measurement KEW3128

Switching the axis subject to zoom

    A short press (within 1 sec) of the ENTER Key switches the Measured

Value Axis and the Time Axis to be zoomed.

 ● Scroll Bar at Measured Value Axis

 ● Scroll Bar at Time Axis

KEW3128 35

KEW3128 6. Measurement

Scrolling of Graph

    Turn the Shuttle Switch to scroll a graph. The Voltage Axis at SV

measurements is fixed and cannot be scrolled.

Switching the displayed graphs

    A long press (1 sec or longer) of the ENTER Key switches Current and

Resistance graphs.

36 KEW3128

6. Measurement KEW3128

Displaying in Full-scale

    A long press (1 sec or longer) of the ESC Key displays a graph in full-

scale. Displaying a graph in full-scale is also possible from the ENTER

Menu (=>P.37). Quit the Graph ZOOM Mode and select  Full-scale
Display from the ENTER Menu.

KEW3128 37

KEW3128 6. Measurement

  6.1.5 Menu

    The Menu is available when   is being displayed on the upper

middle of the LCD.

    Pressing the ENTER Key while   is being displayed on the LCD

pops up the Menu Window.

Move the cursor with the UP/DOWN Keys or
Shuttle Switch, and confirm the selection with
the ENTER Key. Pressing the ESC Key while the
Menu is being displayed closes the Menu Window.
Items displayed with 
with submenus. Press the ENTER Key to access
to the submenus.
Pressing the ESC Key (within 1 sec) while the
submenus are being displayed returns to the
previous screen. A long press (1 sec or longer) of
the ESC Key closes the Menu Window.

 mark are accompanied

38 KEW3128

6. Measurement KEW3128

Followings are the details of each menu item.

Icon Name Function

View Change

Graph ZOOM

Filter

Switches the screens.
(=>P.39 View Change)
Selects the Graph Zoom Mode.
(=>P.39 Graph ZOOM)
Makes setting for the Filter Mode.
(=>P.40 Filter)

Record Records measured results continuously.

Save Saves the measured results only.

Recalls or deletes the data in the internal

Internal Memory

memory.
(=>P.41 Save Data)

Setting Moves to Measurement Setting Screen.

Mode Change Changes Measurement Modes.

Others

EXIT

Makes setting for clock.
(=>P.40 Other Functions)
Exits from Result Display Screen and
returns to Stand-by Mode.

KEW3128 39

KEW3128 6. Measurement

View Change

    Switches among Measured value, Current Graph and Resistance graph

views. Each sub-menu item has following function.

Icon Name Function

Measured value Displays Measured value View.

Current Graph Displays Current Graph View.

Resistance Graph Displays Resistance Graph View.

Graph ZOOM

    Enters into the Graph Zoom Mode (=>P.33 Graph Operation), and

displays a graph in full-scale. Each sub-menu item has following function.

Icon Name Function

Time Axis ZOOM

Measured value
Axis ZOOM

Full-scale Display Displays a graph in full-scale.

Zooms a graph with reference to the Time
Axis (X-Axis).
Zooms a graph with reference to the
Measured Value Axis (Y-Axis).

40 KEW3128

6. Measurement KEW3128

Filter

Switches on/off the Filter Function. (=>P.40 Filter Mode)
   Each sub-menu item has following function.

Icon Name Function

Filter OFF Displays the Measured Value View.

Filter 1 Enables Filter 1

Filter 2 Enables Filter 2

Filter 3 Enables Filter 3

Other Functions

Make settings for the instrument.
   Each sub-menu item has following function.

Icon Name Function

Clock Setting

Print Screen

Demo Mode

Set the clock for KEW3128 instrument.
(=>P.46 Clock Setting)

Save the screen displayed on the LCD as
a BMP (bitmap) file. Act same as a long
press (1 sec or longer) of the Print screen

/Backlight Key.
(⇒P.17 Keys)

Switch to the Demo mode.

(⇒P.46 Demo mode)

KEW3128 41

KEW3128 6. Measurement

  6.1.6 Filter Mode

The KEW3128 has following 3 kinds of Filter Functions.
Filter Mode is effective to reduce the variations in readings due to external

influences during high resistance measurements.

Effectiveness of the Filter Mode becomes stronger when values get bigger. To

check sudden variations in resistances, the Filter Mode should be disabled.

Name Function

Filter OFF Disables the Filter (default setting)
Filter 1 Low-pass Filter (fc = 0.3Hz)
Filter 2 Moving Average (average of 5 data)
Filter 3 Low-pass Filter + Moving Average

  6.1.7 Save Data

Types of Save Data

   The KEW3128 handles following 3 types of data.

  ● Logging Data (REC File)

    Record the measured values (voltage, current and resistance values) at

every 1 sec from the beginning to the end of a measurement.

    The max recording period is 90 min. The     Measurement

Recoding should be selected on the ENTER Menu (=>P.37) while the
instrument is in the Stand-by mode to save the Logging data.

    The time displayed at the top of the LCD indicating the time left that data

can be recorded. (=>P.64)

    Data is saved as RECXX. (XX : 01～32)

  ● Measured Data (SAVE File)

Measured data contains measured results only.
    Select the   Saving Measured Results on the ENTER Menu

(=>P.37) while the measured results are displayed on the LCD.

    Data is saved as SAVEXX. (XX : 01～32)

  ● Print Screen (BMP File)

    Captures and saves the screen images. A long press (1 sec or longer)

of the Print Screen/ Backlight Key saves screen images.

    Data is saved as BMPXX. (XX : 01～32)

42 KEW3128

6. Measurement KEW3128

List of the Saved data

    Select the   Internal Memory on the ENTER Menu (=>P.37). Then a

list of saved data is displayed as follows.

    Functions to recall (⇒displays the saved data), delete (⇒deletes the

saved data) and format the data (⇒formats the internal memory) are

available. Details of each parameter are as follows.

   The latest data is displayed on the top.

KEW3128 43

KEW3128 6. Measurement

Recall the Saved Data

Display a list of the saved data.
Then use the UP/DOWN Key or
Shuttle Switch and move the cursor
onto [LOAD], and press the ENTER
Key. The highlighted cursor i s
displayed, and can be moved on the
files. Put the cursor on a desirable file
with the UP/ DOWN Key or Shuttle
Switch and press the ENTER Key.

   A Confirmation Screen appears. Press

the ENTER Key to load the selected
data.

   Pressing the ESC Key cancels to load

the data.

  Displayed parameters are dependent on the selected files.

  ● Display the Logging data

    The results of the saved data and the graphs of currents and resistances

can be displayed. The available operations against the displayed data
are same to that available when finishing measurements. Press the ESC
Key to return to the previous screen.

    Items displayed at the top of the LCD are as follows.

44 KEW3128

6. Measurement KEW3128

  ● Display the Measured Data

    Only the measured results can be viewed. The Graph Function isnt

available. The available operations against the displayed data are same
to that available when finishing measurements. Press the ESC Key to
return to the previous screen. Items displayed at the top of the LCD are
same to the display for the Logging data.

  ●Display the Print Screen

    Display the saved BMP files. A black frame is displayed with flashing

around the LCD. Press the ESC Key to return to the previous screen.

Delete the saved data

Display a list of the saved data.
Then use the UP/DOWN Key or Shuttle

Switch and move the cursor onto
[DELETE], and press the ENTER Key.

The highlighted cursor is displayed,
and can be moved on the files. Put
the cursor on a file with the UP/DOWN

Key or Shuttle Switch and press the
ENTER Key to delete it.

   A Confirmation Screen appears. Press

the ENTER Key to load the selected
data. Pressing the ESC Key cancels to
load the data.

KEW3128 45

KEW3128 6. Measurement

Format of the Internal Memory

Display a list of the saved data.
Then use the UP/DOWN Key or Shuttle

Switch and m ove the cur sor onto
[FORMAT], and press the ENTER Key.

Then the memory is formatted and the List
Display Screen is displayed.Press the ESC

Key to cancel a format.

Max number of files that can be saved

    The max number of files that can be saved is 32 files in total; addingup

all the Logging, Result and Print Screen data.

    The save capacity is for 43000 data / for about 720 min in total (in case of

Logging data only). Max number of files that can be saved is dependent
on the file type.

File Type

10-min data 32 files
30-min data 23 files

Logging Data

60-min data 11 files
90-min data 7 files

Measured Data 32 files

Print Screen 32 files

Max number of files that can be saved

46 KEW3128

6. Measurement KEW3128

  6.1.8 Clock Setting

Select   Clock Setting on the
ENTER Menu (=>P.37). Adjust the time
in a following order: [year], [month], [day],
[hour], [minute] and [display format].
Pressing the ENTER Key confirms the
entry and proceeds to next step. Press the
ESC Key to return to the previous item.

Pressing the ENTER Key (1 sec or longer)

while [Finish] is highlighted makes the new
setting effective. A long press of the ESC
Key returns to the previous screen.

  6.1.9 Demo Mode

   KEW3128 has a Demo mode function to display simulated data as

measured results without generating output voltages.

   Communication and save operations

work same as that work under normal
mode. The mark flashes at the top
of the LCD while the instrument is in
Demo mode.

   Demo mode isnt canceled after

powering off the instrument.

   Access from the ENTER menu (=> P.

37) to exit from the Demo mode.

KEW3128 47

KEW3128 6. Measurement

 6. 2  Insulation Diagnosis Tests

   This instrument can measure and perform following items as a part of

Insulation resistance Test.

  - Insulation Resistance (IR)

  - Polarization Index (PI)

  - Dielectric Absorption Ratio (DAR)

  - Dielectric Discharge (DD) *Auto-testing

  - Step Voltage Test (SV)

Measurement Mode Function

Insulation
Resistance （IR）

Polarization Index（PI）

Dielectric Absorption
Ratio （DAR）

Dielectric Discharge

（DD）

Step Voltage Test（SV）

Performs normal insulation resistance
measurements (consistent measurements)
Measures resistances twice and calculates
polarization index automatically.

（default value: 1 min, 10 min）

Measures resistances twice and calculates
dielectric absorption ratio automatically.

（default value: 15 sec, 1 min

Calculates dielectric discharge based on the
measured capacitance of the measured object and
residual current values after testing.
Increases the set voltage by 20% every time
when pre-set time comes.

）

48 KEW3128

6. Measurement KEW3128

 6. 3  IR Measurement

  6.3.1 Setting Item

   Setting items for IR measurements are as follows. Refer to Setting for

Measurement (=>P.30) and change the setting values.

Icon Name Details

Output voltage value Voltages to be output

  6.3.2 Measured Result

  The result of IR measurement is displayed as follows.

Displayed Items Details

Insulation

Resistance

Measuring Time Elapsed time from a beginning of a measurement

Pre-set Voltage Pre-set output voltage value

Output Voltage Voltage being output

Insulation

Resistance

Current value Current value being measured

Capacitance Capacitance measured at discharge.

Insulation resistance value being measured

Measured insulation resistance value

KEW3128 49

KEW3128 6. Measurement

 6. 4  PI Measurement (Polarization Index)

  6.4.1 Polarization Index

PI : Polarization Index
   This is a test to check a temporal increase of leakage currents flowing on

insulations. To determine a Polarization Index, first, measure insulation
resistance at 1 min intervals for 10 min. Then, divide the final value by
the initial reading and calculate a ratio. PI is dependent on the shape of

insulations

is important to diagnosis the insulation of cables.

Polarization index =

and influenced by moisture absorption, therefore, a check of PI

TIME 2

Insulation resistance value 3 or 10 min

after starting measurement

TIME 1

Insulation resistance value 30 sec or 1 min

after starting measurement

PI 4.0 or more

Criteria Best Good Warning Bad

4.0 ～ 2.0 2.0 ～ 1.0

1.0 or less

  6.4.2 How to measure PI

  1.  Select the PI（Polarization Index） on the Mode Selection Screen.

Refer to Basic Operation (=>P.21) and operate the Screen.

50 KEW3128

6. Measurement KEW3128

  2. Set Voltage values.

  3. Set TIME1.

4. Set TIME2.

KEW3128 51

KEW3128 6. Measurement

The instrument gets into the Stand-by Mode when settings are made.
   Setting items for PI measurement are as follows. Refer to the Setting for

Measurement (=>P.30) and change settings.

Icon Name Details

Output Voltage Voltage to be output.

PI Time 1

PI Time 2

Measurement doesnt stop when PI Time
1 has been passed.
A measurement stops automatically when
this set time comes. This value should be
bigger than PI TIME 1.

52 KEW3128

6. Measurement KEW3128

  6.4.3 Measured Result

The result of PI measurement is displayed as follows.

PI value

Displayed Items Details

Insulation Resistance Insulation resistance value being measured

Resistance at TIME1,2 Resistance value at TIME1 and TIME2

Pre-set Voltage Pre-set output voltage value

Output Voltage Voltage being output

PI Polarization Index value

Insulation Resistance Measured insulation resistance value

Current value Current value being measured

Capacitance Capacitance measured at discharge.

KEW3128 53

KEW3128 6. Measurement

6. 5  DAR Measurement (Dielectric Absorption Ratio)

  6.5.1 Dielectric Absorption Ratio

DAR : Dielectric Absorption Ratio
   DAR measurement is almost same to PI measurement in a sense that

they test the time course of insulation. The only difference is that DAR
measurement can get result faster than the other.

TIME2

Dielectric

Absorption

Ratio

=

Insulation resistance value 30 sec or 1 min

after starting measurement

TIME1

Insulation resistance value 15 or 30 sec

after starting measurement

DAR 1.4 or more

Criteria Best Good Bad

1.25 ～ 1.0

1.0 or less

54 KEW3128

6. Measurement KEW3128

  6.5.2 How to measure DAR

  1. 

Select the DAR（Dielectric Absorption Ratio） on the Mode Selection
Screen. Refer to Basic Operation (=>P.21) and operate the Screen.

  2. Set Voltage values.

  3. Set TIME1.

KEW3128 55

KEW3128 6. Measurement

  4. Set TIME2.

Setting items for DAR measurement are as follows. Refer to the Setting for

Measurement (=>P.30) and change settings.

Icon Name Details

Output Voltage Voltage to be output.

DAR Time 1

DAR Time 2

Measurement doesnt stop when
PI Time 1 has been passed.

A measurement stops automatically when
this set time comes.
This value should be bigger than PI TIME 1.

56 KEW3128

6. Measurement KEW3128

  6.5.3 Measured Result

  The result of DAR measurement is displayed as follows.

DAR value

Displayed Items Details

Insulation Resistance Insulation resistance value being measured

Resistance at TIME1,2 Resistance value at TIME1 and TIME2

Pre-set Voltage Pre-set output voltage value

Output Voltage Voltage being output

DAR Dielectric Absorption Ratio

Insulation Resistance Measured insulation resistance value

Current Current value being measured

Capacitance Capacitance measured at discharge.

KEW3128 57

KEW3128 6. Measurement

 6. 6  DD Measurement (Dielectric Discharge)

  6.6.1 Dielectric Discharge

DD : Dielectric Discharge
   This measurement method is usually used to diagnosis multi-layer

insulations, which requires the instrument to measure the discharge current
and capacitance of the measured object 1 min after the removal of the
test voltage. This is a very good diagnostic insulation test that allows
deterioration and other problems voids in the multiple insulations to be
assessed.

Current value 1 min after

Dielectric

Discharge

=

completing measurement (mA)

Voltage value when a measurement

complete x Capacitance (F)

DD 2.0 or less

Criteria Good Warning Poor Very Poor

   This criteria is a guide and could be slightly changed and be adapted to

particular objects under test based on practical experience of the users.

   This method has been established to test high voltage generators installed

in electric power plants in the Europe countries.

2.0 ～ 4.0 4.0 ～ 7.0

7.0 or more

58 KEW3128

6. Measurement KEW3128

  6.6.2 How to measure DD

  1.  Select the DD（Dielectric Discharge） on the Mode Selection

Screen. Refer to Basic Operation (=>P.21) and operate the Screen.

  2. Set Voltage values.

  3. Set TIME.

KEW3128 59

KEW3128 6. Measurement

   Setting items for DD measurement are as follows. Refer to the Setting for

Measurement (=>P.30) and change settings.

Icon Name Details

Output Voltage Voltage to be output

Measuring Time

Measurements stop automatically and
DD values are calculated.

60 KEW3128

6. Measurement KEW3128

  6.6.3 Measured Result

   The result of DD measurement is displayed as follows.

DD value

Displayed Items Details

Insulation Resistance Insulation resistance value being measured

Measuring Time Elapsed time from a beginning of a measurement

Pre-set Voltage Pre-set output voltage value

Output Voltage Voltage being output

DD Dielectric Discharge

Insulation Resistance Measured insulation resistance value

Current Current value being measured

Capacitance Capacitance measured at discharge.

KEW3128 61

KEW3128 6. Measurement

6. 7  SV Measurement (Step Voltage)

  6.7.1 Step Voltage

SV : Step Voltage
   This is a test based on the principle that an ideal insulation will produce

identical readings at all voltages, while an insulation which is being over
stressed, will show lower insulation values at higher voltages. During the
test, the applied voltage incrementally steps by a certain voltage taking

successive 5-time measure

when insulation resistances become lower at higher applied voltages.

ment. Degradation of insulation may be doubt

  6.7.2 Measurement Setting Items

  1.  Select the SV（Step Voltage） on the Mode Selection Screen. Refer

to Basic Operation (=>P.21) and operate the Screen.

  2. Set Voltage values.

62 KEW3128

6. Measurement KEW3128

  3. Set Step Time.

   Setting items for SV measurement are as follows. Refer to the Setting for

Measurement (=>P.30) and change settings.

Icon Name Details

Output Voltage Voltage to be output

Step Time Time per step

KEW3128 63

KEW3128 6. Measurement

  6.7.3 Measured Result

   The result of SV measurement is displayed as follows.

Displayed Items Details

Insulation Resistance Insulation resistance value being measured

Resistance at each

Step time

Pre-set Voltage Pre-set output voltage value

Output Voltage Voltage being output

Insulation Resistance Measured insulation resistance value

Current Current value being measured

Capacitance Capacitance measured at discharge

Resistance value at each Step time (V1 – V5)

64 KEW3128

6. Measurement KEW3128

 6. 8 Measurement Screen

Displayed items at the top of the LCD

Displayed Items Details

Measurement Mode Mark of the selected Measurement Mode

REC mark/ Possible

Recording Period

Filter Mode Mark of the selected Filter

ENTER Menu

Battery Mark

Time Present time and date

Displayed when REC is specified.
Possible recording time is displayed with a bar
graph and numbers.

Accessible to the ENTER Menu when pressing the
ENTER Key while this icon is being displayed.

Mark indicating the level of battery
mark is displayed when the instrument is operating
with an external power supply.

voltage.Different

KEW3128 65

KEW3128 6. Measurement

Items displayed at Result Display Screen

   Following items are displayed on the LCD in stand-by mode and during a

measurement.

Displayed Items Details

Live Voltage Warning

Bar Graph

Measurement

Information

Measurement Time Elapsed time after a start of measurement

Pre-set Voltage Pre-set output voltage value

Output Voltage Voltage being output

Insulation Resistance Insulation resistance value being measured

Current Current value being measured

Pre-set Value Pre-set values for each Measurement Mode

Displayed while voltages are being output.Flashing
status shows discharge is in progress.

Bar graph indicating the measured insulation
resistances

Supplementary info about each measurement
mode.

66 KEW3128

6. Measurement KEW3128

Items displayed at Graph Display Screen

   Following items are displayed on the LCD with in stand-by mode and During

a measurement.

Displayed Items Details

Live Voltage Warning

Graph

Axis for Current/

Resistance values

Displayed while voltages are being output.
Flashing status shows discharge is in progress.

Bar graph indicating the measured insulation
resistances.

Axis is switched between current and resistance
values depending on each graph.

Measuring Time Elapsed time after a start of measurement

Pre-set Voltage Pre-set output voltage

value

Output Voltage Voltage being output

Voltage Axis

(in SV Mode)

Voltage Axis is displayed only in the SV
Measurement Mode.

Pre-set Value Pre-set values for each measurement mode

KEW3128 67

KEW3128 6. Measurement

 6. 9  Capacitance Measurement

  6.9.1 Measurement Screen

Displayed Items Details

Capacitance value

Measuring Time Elapsed time after a start of measurement

   At capacitance measurements, measured values are displayed when

insulation resistance measurements complete. When the output voltages
are 80% or less of the preset voltage values at an insulation resistance
measurement

   KEW3128 has a Protect Mode to limit charge currents in order to protect

the instrument when measuring 10uF or higher. In this mode, a message

Protect modeis displayed on the LCD.

   The instrument exits from the Protect Mode automatically when a battery

charge completes or 5 min pass after entering into this mode.

, readings for capacitance become---.

Displays capacitance values of the measured
object after insulation resistance tests.

68 KEW3128

6. Measurement KEW3128

 6. 10  Voltage Measurement

  6.10.1 Measurement Screen

  The result of Voltage measurement is displayed as follows.

Displayed Items Details

Frequency Frequency being measured

DC / AC Display DC / AC of measurement voltage

Voltage Voltage value being measured

KEW3128 69

KEW3128 6. Measurement

 6. 11  Other Functions

  6.11.1 Use of Guard Terminal

   When measuring insulation resistances of a cable, leakage currents flowing

on the surface of cable jacket and the currents flowing inside the insulator
are mixed and may cause error in readings. In order to prevent such error,
wind a conductive wire around the point where leakage currents flow.

Then connect it to the Guard terminal as shown in the below figure.
   This is to move out the surface leakage resistance of the cable insulation

to measure only the volume resistance of insulator. Use the Guard cord
supplied with this instrument to connect the instrument and the Guard
terminal.

  G Terminal Earthing Procedure

   The G Terminal Earth System is a measurement method using a Guard

Terminal which is appropriate to measure the whole electrical paths
including high-voltage cable with the other high-voltage devices.Connect
the Guard Terminal to the Earth Electrode of the measured object and the
shielded wire of the cable to the Earth Terminal. In this case, disconnect the
shielded wire of the cable from the Earth Electrode.

   To use this measurement method, the insulation resistance of sheath

(between the shielded wire and the ground) should be 1MΩ or more.

6. Measurement KEW3128

LINE

Guard Cord

Earth Cord

  Use of Guard Terminal at high resistance measurements

   It may take longer time to obtain accurate readings when measuring high

resistances of 100GΩ or higher while the instrument is operated with
battery instead of an external power supply.

   In this case, wind the Guard Cord connected to the Guard Terminal to the

Earth Cord. Then accuracy of the readings gets better.

  6.11.2 Backlight Function

   This function to facilitate working at dimly illuminated location or at nighttime

work. Press the Backlight Button when the Range Switch is at any position
other than OFF. The Backlight will light up for about 1 min., and then
turned off automatically.

  6.11.3 Auto-power-off Function

   The instrument automatically turns off approx. 10 min after the last switch

operation. When measurements are conducted with Timer Function, the
instrument automatically turns off approx. 10 min after measurement. To
return to the normal mode, turn the Range Switch to the OFF position, then
to the desired position.

70 KEW3128

KEW3128 7. Battery Charging and Replacement

7. Battery Charging and Replacement

 7. 1  How to charge battery

# DANGER

Use the special cord supplied with this instrument only. Firmly connect the
Power Cord to an outlet. Never connect it to a device on which electrical
potentials higher than AC240V exist.
Handling and storage instructions specified by the battery manufacturer
should be observed.

# WARNING

Connect the Power Cord to the instrument first. Cord to be firmly inserted.
Do not use the Cord if any abnormal conditions such as cracks or exposed
metal parts are present. When unplugging the Cord from the mains socket
outlet, do so by removing the Plug first and not by pulling the Cord.

① Set the Range Switch to the OFF position.
  ② Confirm a battery is installed in the instrument.
  ③  Connect the Power Cord to the instrument to feed power to the

instrument.

  ④  LED Status Indicator flashes in red and the Battery Mark also flashes

on the LCD.

  ⑤  The indicator lights up in green and the Battery Mark on the LCD stops

flashing and lights up. (Battery charge completes in about 8 hours.)

* Battery life and how many times can be charged are depended on conditions of

use and environment.

* Storing rechargeable lead-acid batteries in a low-charged state could lead to

reduced life and/or damage. When storing the battery for a long period, check
and charge the battery at regular intervals.

KEW3128 71

72 KEW3128

7. Battery Charging and Replacement KEW3128

 7. 2  How to Replace Battery

# DANGER

Never open the Battery Compartment Cover while making a measurement.

# WARNING

To avoid possible electric shock, remove test leads before opening the Battery
Compartment Cover. After replacing battery, be sure to tighten up the screw
for Battery Compartment Cover.

# CAUTION

Install a battery in correct polarity as marked inside.

① Remove the Power Cord from the instrument.
  ②  Set the Range Switch to OFF position, and remove the Test Leads

from the instrument.

  ③  Remove the Battery Compartment Cover-fixing screws, and slide the

Cover upwards to remove it. （Attention should be paid not to lose
screws.）

KEW3128 73

KEW3128 7. Battery Charging and Replacement

+ (positive)

red

- (negative)
black

  ④ Pull out the Tray toward, and take the battery out.

  ⑤  Pull up the Battery Connectors upward as indicated by arrow mark in

the below left illustration, and remove them.

  ⑥  Remove the old battery and install a new one (rechargeable lead

  ⑦  Install the Battery Compartment Cover so that the surfaces of the Cover

storage battery PXL-12050: 12V 5Ah). Check the orientation of the
connectors (see above illustration on the right) and no deformation on
the metal terminals and install a battery in correct polarity. Then, insert
the Tray fully.

and the instrument become flat, and fix it with screws.

74 KEW3128

8. Communication Function/ Supplied Software KEW3128

8. Communication Function/ Supplied Software

● Interface
    USB communication is possible by using this instrument with the supplied

USB Adapter (M-8212).

    Communication method: USB Ver1.1

Followings can be done by USB communication:
    * Downloading a file in the internal memory of the instrument to a PC
    * Making settings for the instrument via PC.
    * Displaying the measured results as a graph and saving them in real-

time.

● Software
    KEW Windows for KEW3128 (Supplied CD-ROM )

● System Requirements
    * OS (Operation System)
    Windows2000/XP/VISTA（CPU: Pentium III 800MHz or higher）
    * Memory
    256Mbyte or more
    * Display
    Resolution 1024 × 768 dots, 65536 colors or more
    * HDD (Hard-disk) space required
    100Mbyte or more
    * .NET Framework (2.0 or later)

● Trademarks
    * Windows® and Microsoft® Excel are the registered trademark of

Microsoft in the United States.

    * Pentium is a registered trademark of Intel in the United States.

KEW3128 75

KEW3128 8. Communication Function/ Supplied Software

 8. 1  How to install the Software

   Followings are the instructions to install the software KEW Windows and

KEW Windows for KEW3128.

  ① Before installing the software, followings shall be checked.

   ● To prepare your system to install this software, please close all open

programs.

● Be sure NOT to connect the instrument with USB until install is
completed.

   ● Installation shall be done with administrative right.

② Insert the CD-ROM in your PC's CD-ROM drive.
    When the setup program doesn't run automatically, double click the

"KEWLauncher.exe".

    Then following window appears. ClickNext.

76 KEW3128

8. Communication Function/ Supplied Software KEW3128

  ③  Read through and understand the License Agreement, and

checkI accept….. Then click Next.

  ④  Enter the user information and specify the location to where install the

software. Then click Next.

KEW3128 77

KEW3128 8. Communication Function/ Supplied Software

  ⑤  Confirm the information on install, and click Install to start installing.

  ⑥ Click Finish when install completes.

78 KEW3128

8. Communication Function/ Supplied Software KEW3128

  ⑦  An installation of KEW Windows for KEW3128 is followed by the

installation of KEW Windows.

    ● To install the KEW Windows for KEW3128", you can follow the

same installation procedure described for KEW Windows .

If you need to remove this software, use the Add/Remove Programs tool in
the Control Panel.

KEW3128 79

KEW3128 8. Communication Function/ Supplied Software

 8. 2 How to start KEW Windows for KEW3128

  ● Start and Quit

    Start the software by; 1) clicking the icon for [KEW Windows] on the desktop,

or 2) clicking [Start] → [Program] → [KEW] → [KEW Windows]. Then the
KEW products, which have been installed in the KEW Windows, are
listed up. Select the KEW3128 on the list, and then click Next. Then
a main menu for KEW Windows for KEW3128 appears. Click [Data
Download] or [Instrument Setting].

9. Accessories KEW3128

Standard Tip Metal
Hook Type

Male Thread

Hexagon Socket

Tip Metal Straight Type
(accessory)

9. Accessories

  9. 1  Metal parts for Line Probe, and replacement

① Metal Parts
   Standard, Hook Type: To be used to hook the instrument.

   MODEL 8029: Tip metal, Straight Type（accessory）

② How to replace the metal parts
   Turn the Line probe counterclockwise to remove the attached tip metal.
    Put the tip metal you want to use to the hexagon socket and turn it to

clockwise together with the tip of probe, and tight up screws.

（Shipped out with being attached to the Line Probe）

80 KEW3128

KEW3128 10.Disposing the Product

10. Disposing the Product

Waste Electrical and Electronic Equipment (WEEE), Directive 2002/96/EC

This Product complies with the WEEE Directive (2002/96/EC) marking
requirement. The affixed product label (see below) indicates that you must not
discard this electrical/electronic product in domestic household waste.

Product Category

With reference to the equipment types in the WEEE directive Annex 1, this
product is classified as a Monitoring and Control instrumentation product.

Disposing lead-storage batteries

When you throw away the batteries, be sure to cover their positive and negative
terminals and always observe local laws and regulations.
Insufficient insulation of the terminals may cause explosion or fire because
electrical energies remain in lead-storage batteries after use.

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82 KEW3128

Contents KEW3128

KEW3128

MEMO

KEW3128 83

KEW3128

MEMO

DISTRIBUTOR

Kyoritsu reserves the rights to change specifications or designs described in this
manual without notice and without obligations.

08-12 92-1997C