Kyoritsu Electrical Instruments 3123A User manual

KEW 3121A, 3122A, 3123A

KEW3121A, 3122A KEW3123A

INSTRUCTION MANUAL

HIGH VOLTAGE INSULATION TESTER

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CONTENTS

Page

1．Safety warnings …………………………………………………1

2．Features …………………………………………………………2

3．Specifications ………………………………………………3 〜 4

4．Instrument Layout ………………………………………………5

5．Operating Instructions …………………………………………6

  5-1．Mechanical Zero Adjustment ……………………………6

  5-2．Battery Check ……………………………………………6

  5-3．Insulation Resistance Measurement ……………………7

  5-4．Continuous Measurement ………………………………7

  5-5．Use of Guard Terminal ……………………………………8

6．Battery Replacement ……………………………………………9

7．Accessories and options ………………………………………9

  7-1. Metal part for Line Probe, and replacement ……………9

  7-2. How to use the adaptor for recorder …………………10

8．How to fix the Meter to the Hard case ………………………11

9．Cleaning Meter Cover …………………………………………12

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1. Safety warnings

Please read through these operating instructions before using the
instrument to avoid any dangers such as electrical shock and to
ensure safe operation of the instrument.

Pay particular attention to all WARNING and CAUTION in this
instruction manual. WARNING indicates warnings to avoid electrical
shock and CAUTION indicates cautions to avoid damage to the
instrument.

#

WARNING

● Th

is instrument cannot test live conductors. Ensure that the

circuit to be tested is powered off before performing a test.

● Never open the Battery cover or remove the Instrument panel

during a measurement.

● Confirm that the Rotary switch is at the OFF position, and then

connect the test leads.

● Do not attempt to make measurement in the presence of

flammable gasses. Otherwise, the use of the inst

rument may

cause sparking, which can lead to an explosion.

● Never attempt to make any measurement if any abnormal

conditions, such as a broken cover or exposed metal parts are
present on the Instrument or test leads.

● Set the Function switch to OFF position after use, and ensure

the Test button is released and unlocked.

#

CAUTION

● Do not ex pose the ins trume nt t o dire ct sunli ght, hi gh

temperature

s, humidity or dew.

● Never leave the instrument in the environment of 60˚C or

higher temperatures.

● Do not use the instrument if it or test lead is wet.

● Remove the batteries if the instrument is to be stored and will

not be in use for a long period.

● Use a damp cloth with neutral detergent or water for cleaning

the instrument. Do not use abrasives or solvents.

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2. Features

●  Battery powered, the inst ruments test insula tion up to
100000MΩ at 2500V for KEW 3121A, 200000MΩ at 5000V
for KEW 3122A and 200GΩ at 5000V and 400GΩ at 10000V
for KEW 3123A.

●  Suited for heavy duty electrical maintenance and servicing of
industrial installations, cables, transformers, generators and
switchgear where high voltage insulation tests are required.

●  Dual sc a l e s fo r l o w a n

d high ranges wh i c h ch a ng e
automatically. Colour coded scales for easy reading plus
LED's that illuminate in matching colour.

●  Drip proof construction. The case is sealed with rubber

gaskets to protect internal circuit against rain.

●  Hard carrying case furnished as standard accessory. Houses

both instrument and test leads in compact form. Made of
plastic, it is highly water resistant.

●  Designe

d for low power consumption. Since the maximum

current consumption is 90mA eight pieces of 1.5V SUM-3（or
equivalent ） permit about 6 hours of continuous operation
even when the instrument is used on maximum load or twice
longer on minimum load.

●  Rated output voltage is maintained down to 100MΩ for KEW
3121A, 200MΩ for KEW 3122A and 0.2GΩ/0.4GΩ for KEW
3123A. This permits accurate measurements of

low insulation

resistance.

●  Optional adapter MODEL8324 is available for connection to
recorder and enables cable insulation monitoring.

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0〜5GΩ/2〜200GΩ

(automatic change)

0〜10GΩ/4〜400GΩ

(automatic change)

±5% of reading

（0.2〜100GΩ）

±10% of reading

or 0.5% of scale length

（ ranges other than

listed above）

at 23℃ ±5℃

±5% of reading

（0.4〜200GΩ）

±10% of reading

or 0.5% of scale length

（ ranges other than

listed above）

at 23℃ ±5℃

±10% of reading

（0.2〜100GΩ）

±20% of reading

or 1.0% of scale length

（ ranges other than

listed above）

at −10℃〜＋40℃

±10% of reading

（0.4〜200GΩ）

±20% of reading

or 1.0% of

scale length

（ ranges other than

listed above）

at −10℃〜＋40℃

5000V ±5%

（0.2~100GΩ）

10000V ±5%

（0.4~200GΩ）

& housing case

Hard Carrying Case:M-9158 Batteries, Test Leads (Line
Probe:M- 7165A, Earth Cord :M-7224 A, Guard Cord:M­7225A) Pickel type prod:M-8019

Line cord with alligator clip：M-7168A
Optional adapter：M-8324

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KEW 3121A KEW 3122A KEW 3123A

DC Test Voltage 2500V 5000 V 5000V 10000V

Measuring Ranges

0〜2000MΩ/

1000〜100000MΩ

（automatic change）

0〜5000 MΩ/

2000〜 200000MΩ

(automatic change)

0〜5GΩ/2〜200GΩ

(automatic change)

0〜10GΩ/4〜400GΩ

(automatic change)

Accuracy

Insulation
Resistance

±5% of reading

（100〜50000MΩ）

±10% of reading

or 0.5% of scale length

（ ranges other than

listed above）

at

23℃ ±5℃

±5% of reading
（200〜 100000MΩ）
±10% of reading

or 0.5% of scale length

（ ranges other than

listed above）

at 23℃ ±5℃

±5% of reading

（0.2〜100GΩ）

±10% of reading

or 0.5% of scale length

（ ranges other than

listed above）

at 23℃ ±5℃

±5% of reading

（0.4〜200GΩ）

±10% of reading

or 0.5% of scale length

（ ranges other than

listed above）

at 23℃ ±5℃

±10% of reading

（100〜50000

MΩ）

±20% of reading

or 1.0% of scale length

（ ranges other than

listed above）

at −10℃〜＋40℃

±10% of reading
（200〜 100000MΩ）
±20% of reading

or 1.0% of scale length

（ ranges other than

listed above）

at −10℃ 〜＋40℃

±10% of reading

（0.2〜100GΩ）

±20% of reading

or 1.0% of scale length

（ ranges other than

listed above）

at −10℃〜＋40℃

±10% of reading

（0.4〜200GΩ）

±20% of reading

or 1.0% of

scale length

（ ranges other than

listed above）

at −10℃〜＋40℃

Output
Voltage

2500V ±5%

（100〜50000MΩ）

5000V ±5%
（200〜 100000MΩ）

5000V ±5%

（0.2~100GΩ）

10000V ±5%

（0.4~200GΩ）

Operating
Temperature & Humidity

−10℃ 〜＋40℃ at 85% max. relative humidity

Storage
Temperature & Humidity

−20℃ 〜＋60℃ at 90% max. relative humidity

Insulation Resistance 1000MΩ max./ 1000V between electrical circuit

& housing case

Withstand Voltage 5000V AC for one minute between electrical circuit & housing case
Dimensions 200（L）×140（W）×80（D）mm
Weight Approx. 1kg（including batteries）

Power Source 8 pcs of R6P (AA) battery or equivalent

Accessories

Hard Carrying Case:M-9158 Test Leads
(Line Probe:M-7165A,

Earth

Cord:M-7224A, Guard Cord:M-7225A)

Hard Carrying Case:M-9158 Batteries, Test Leads (Line
Probe:M- 7165A, Earth Cord :M-7224 A, Guard Cord:M-
7225A) Pickel type prod:M-8019

Optional accessories

Line cord with alligator clip：M-7168A
Optional adapter：M-8324
Pickel type prod:M-8019

Line cord with alligator clip：M-7168A
Optional adapter：M-8324

3. Specifications

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④

⑤

③

②

①

④

⑦

⑥

⑧

⑪ ⑩ ⑨

4. Instrument Layout

① Line Terminal
② Guard Terminal
③ Earth Terminal
④ LE D's for Hi gh & Low

Range Indication

⑤ Press to Test Button
⑥ Function Switch
⑦ Me ter Movem ent Ze ro

Adjust

⑧ Bat t ery Co mpartme n t

Cover

⑨ Line Probe (Red)
⑩ Earth Cord (Black)
⑪ Guard Cord (Green)

Fig.1

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CAUTION:
BE CAREFUL ABOUT HIGH VOLTAGE PRESENT ACROSS LINE
AND EARTH TERMINALS OF INSTRUMENT WHEN PRESS TO
TEST BUTTON IS OPERATED. MAKE SURE TO EARTH CIRCUIT
UNDER TEST. ALWAYS CONNECT EARTH TERMINAL OF
INSTRUMENT TO EARTH. THE BUZZER WILL KEEP SOUNDING
DURING INSULATION RESISTANCE MEASUREMENT.

5-1. Mechanical Zero Adjustment

With the function switch set at OFF position, adjust the meter
pointer to

∞ mark on the scale. Use a screwdriver to turn the

zero adjust screw located at the center of the front panel.

5-2. Battery Check

With the function switch set at BATT. CHECK position, operate the
press to test button. The batteries are good when the pointer stays
in BATT. GOOD area or to the right of this area. If not, replace them.

Note:  Refrain from holding down or locking the press to

test butt

on during this test as it will result in current
co nsump tion larger tha n insula tion re sist ance
measurement while the batteries are still new.

5. Operating Instructions

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5-3. Insulation Resistance Measurement

With the function switch set at OFF position, always connect the
circuit under test to earth. Attach the test lead to the earth terminal
of the instrument and connect to the earthed side of the circuit
under test. With the function switch set at 2500V and 5000V for
KEW 3121A and 3122A or 5000V or 10000V for KEW 3123A,
connect the black earth code to the earth

terminal (EARTH) and
place the line probe in contact with the circuit under test and press
the Test button. When the green LED illuminates, read insulation
resistance on the outer scale (for high range). Use the inner scale
where the red LED illuminates. For insulation testing at 5000V
and 10000V, read the black and red scales respectively (for KEW
3123A). After a test, release the press to test b

utton and wait for
several seconds without disconnecting the line probe from the
circuit tested. This is intended to discharge the charge stored in the
circuit tested.

5-4. Continuous Measurement

Make sure that the circuit under test is earthed and that the test
lead attached to the earth terminal of the instrument is connected
to the earthed side of the circuit under test. Push the press to test
bu

tton and turn clockwise to lock for continuous measurement.
When making this measurement, good care must be taken against
the high voltage continuously present across the line and earth
terminals of the instrument.

Note:  Make certain that the circuit under test does not

include components which will be damaged by the
high voltage applied.

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5-5. Use of Guard Terminal

When measuring the insulation resistance of a cable, Ieakage
current flowing on the surface of cable jacket and the current
flowing inside the insulator are mixed and may cause error in
insulation resistance value. In order to prevent such error, wind a
conductive wire around the point where leakage current flows. Then
connect it to the Guard terminal as shown in below Fig

.2. This is
to move out the surface leakage resistance of the cable insulation
to measure only the volume resistance of insulator. Make sure to
use the Guard cord supplied with this instrument to connect the
instrument to Guard terminal.
Connect the terminals with reference to the following figure of an
equivalent circuit.
* Wind a protective wire, any conductive bare wires are ok, around

the point

where leakage currents flow. Then connect it to the

Guard terminal as follows.

* It is possible to move out the surface leakage resistance of the

insulation and measure only the volume resistance by using the
Guard terminal. This is helpful when performing tests in humid air.

Fig.2

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Remove the battery compartment cover by loosening the screw located
on the back of the housing case. Replace the whole battery pack. Alkaline
batteries are recommended where the instrument is used at a temperature
below the freezing point. The ordinary manganese batteries will deteriorate
below the freezing point.

6. Batttery Replacement

7-1. Metal part for Line Probe, and replacement

（1）Tip metal parts

MODEL8252: Standard Prod (straight type, with molded parts)
MODEL8254: Straight Type Prod
MODEL8019: Pickel Type Prod (accessory)
To be used to hook the instrument.

  Note:Option KEW3121A, KEW3122A

（2）How to replace it

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.

7. Accessories and options

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To shield or Earth

To recorder

Fig.3

7-2. How to use the adaptor for recorder

MODEL8324 is the adaptor for recorder for output current measurement. Connect

it as shown in the below Fig.3.

Output is DC10mV when current of 1μA is flowing．

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8. How to fix the Meter to the Hard case

Please f ollow the instr uctions below t o fix MODEL9159 main unit to
MODEL9158 Hard case with Dual lock fastener.

1. Place a hard board beneath the Hard case.
The board should be located under the fastener attached to the Hard

case.

2. Put the unit in place, and then press down the sides of the unit so that

the mushroom-shaped stems on the fastener are engaged each other
with audible snap sound.

Duallockfastener

Ahardboardshouldbeplacedinthe
locationasindicatedbydottedlines.

Pressingdownthesidesofunit(as
indicatedbyarrowmarks)engages
thestemsonthefastener.

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9. Cleaning Meter Cover

This earth tester is managed by our company's quality standard and is
delivered in the best condition after passed the inspection. But in the dry
time of winter static electricity sometimes builds up on the meter cover due
to the characteristic of plastic.
When the pointer deflects by touching the surface of this tester or zero
adjustment can not be made, do not try to make measurement.
When static electricity builds up on the meter cover and affects the meter
reading, use a cloth dampened with off-the-shelf anti-statics agent or
detergent to wipe the meter cover surface.

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