Kyoritsu Electrical Instruments 3131A User manual

INSTRUCTION MANUAL

ANALOGUE INSULATION / CONTINUITY TESTER

MODEL

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3131

A

Contents

1. Safety Warnings .................................................................................... 1

2. Features ............................................................................................... 5

3. Specifications ...................................................................................... 6

4. Instrument Layout ................................................................................. 8

5. Preparation for Testing ......................................................................... 10

 5-1 Removing the Cover ...................................................................... 10

 5-2 Mechanical Zero Adjustment .......................................................... 11

 5-3 Battery Voltage Check ................................................................... 11

 5-4 Test Probe Connection .................................................................. 11

 5-5 Test Probe Check ......................................................................... 11

6. Operation ........................................................................................... 12

 6-1

Disconnection and Check of Power Source of Circuit Under Test

 6-2 Insulation Resistance Measurement ................................................ 13

 6-3 Continuity Testing (Resistance Tests) ............................................. 14

 6-4 Continuous Measurement .............................................................. 15

7. Back Light Function ............................................................................ 16

8. Battery & Fuse Replacement ............................................................... 17

 8-1 Battery Replacement ...................................................................... 17

 8-2 Fuse Replacement ........................................................................ 17

9. Notes on Accessories .......................................................................... 18

 9-1 How to Fit Strap Belt & Test Probe Pouch ........................................ 18

10. Cleaning of the Instrument .................................................................... 19

11. Service ............................................................................................... 19

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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 passed the inspection. This instruction manual contains
warnings and safety rules which must be observed by the user to ensure safe
operation of the instrument and retain it in safe condition. Therefore, read
through these operating instructions before using the instrument.

WARNING

#

● 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. Kyoritsu is by no means liable for any damage
resulting from the instrument in contradiction to these cautionary notes.

○ The symbol

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

#

WARNING ：is reserved for conditions and actions that can cause

#

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

#

indicated on the instrument, means that the user must refer

#

cause serious or fatal injury.

serious or fatal injury.

or instrument damage.

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Please refer to following explanation of the symbols used on the instrument and
in this manual.

User must refer to the explanations in the instruction manual.

#

Caution, risk of electric shock.



Instrument with double or reinforced.



Protection against wrong connection is up to 440V.

EARTH GROUND



This instrument satisfies the marking requirement defined in the WEEE
Directive 2002/96/EC. This symbol indicates separate collection for
electrical and electronic equipment.

# DANGER

●

Confirm a proper operation of the instrument with a well-known power supply.

● Do not use this instrument on energized (LIVE) circuits.

●

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.

● Do not make measurement when thunder is rumbling. If the instrument is

in use, stop the measurement immediately and remove the instrument
from the measured object.

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

● Never open the battery compartment cover and the instrument case when

making a measurement.

● Do not exceed the maximum allowable input of measuring ranges.

●

The instrument is to be used, only in its intended applications or conditions.

  Otherwise, safety functions equipped with the instrument doesn't work,

and instrument damage or serious personal injury may be caused.

● Always Keep your fingers and hands behind the protective fingerguard on

test probe to avoid the possible shock hazard.

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# WARNING

● Never attempt to make any measurement, if the instrument has any

structural abnormality such as cracked case or exposed metal parts.

● Do not turn the range selector switch while the test probe are connected

to the circuit under test.

● Do not install substitute parts or perform any unauthorized modification of

the instrument. Return the instrument to Kyoritsu or your distributor for
service and repair to ensure the safety features are maintained.

● Do not try to replace the batteries and fuse if the surface of the

instrument is wet.

● Firmly insert the plug into the terminal when using test probe.

● Make sure to disconnect the test probe from the instrument before

opening the battery compartment cover for battery and fuse replacement.

● Stop using the test lead if the outer jacket is damaged and the inner metal

or color jacket is exposed.

# CAUTION

● Always make sure to set the range selector switch to the appropriate

position before making measurements.

● Do not expose the instrument to the direct sun, dew fall or extreme

temperature and humidity.

● When the instrument will not be in use for a long period of time, place it in

storage after removing batteries.

● Use a damp cloth soaked in water or neutral detergent for cleaning the

instrument. Do not use abrasives or solvents.

● Keep your fingers and hands behind the protective fingerguard during

measurement.

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Measurement categories (Over-voltage categories)
To ensure safe operation of measuring instruments, IEC 61010 establishes
safety standards for various electrical environments, categorized as O to CAT IV,
and called measurement categories.
Higher-numbered categories correspond to electrical environments with greater
momentary energy, so a measuring instrument designed for CAT III environments
can endure greater momentary energy than one designed for CAT II.
O : Circuits which are not directly connected to the mains power supply.
CAT II : Primary electrical circuits of equipment connected to an AC

CAT III : Primary electrical circuits of the equipment connected directly to

CAT IV : The circuit from the service drop to the service entrance, and to the

electrical outlet by a power cord.

the distribution panel, and feeders from the distribution panel to
outlets.

power meter and primary overcurrent protection device (distribution
panel).

O: Device which is
not directly
connected to the
mains power supply

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2. Features

MODEL-3131A is an analogue insulation tester with five ranges for insulation
resistance measurement and continuity testing (resistance tests) of low voltage
installations.

● Designed to safety standards:
  IEC61010-1
  IEC61010-031
  IEC 61557-1,2,4,10

● Dust and drip proof constrution to IP54

● Three insulation test ranges : 250V/100MΩ, 500V/200MΩ, 1000V/400MΩ

● Two continuity test ranges : 2Ω, 20Ω

● Back light function to facilitate work at night or dimly lit locations

● Easy for battery check

● Power-on indication LED lighting during battery check and measurement

● Live circuit warning indication with LED lighting and the buzzer sound

● Fuse protected.

● Color coded scales and range switch position for easy reading

● Uses only 6× 1.5V battery type R6, AA or equivalent

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3. Specifications

● Measuring Range and Accuracy (at 23±5℃, relative humidity 45-75%)
  Insulation Resistance Ranges:(IEC 61557-2)

Nominal Output Voltage
Measuring Ranges
Open-Circuit

Voltage
Short-Circuit

Current

Nominal Current

Accuracy

250V 500V 1000V

0 - 100MΩ

250V DC +20% max.

1mA DC min.

at 0.25MΩ

±5% of indicated value

at 0.1MΩ- 10MΩ

±0.7% of scale length at ranges other than above ranges

0 - 200MΩ

500V DC +20% max.

1.3mA approx

1mA DC min.

at 0.5MΩ

±5% of indicated value

at 0.2MΩ- 20MΩ

0 - 400MΩ

1000V DC + 20% max.

1mA DC min.

at 1MΩ

±5% of indicated value

at 0.4MΩ- 40MΩ

  Continuity Test (Resistance Test) Ranges:(IEC 61557-4)

Ranges
Measuring Ranges
Open-Circuit Voltage
Measuring Current
Accuracy
Zero Adjustment Range

x 1Ω

0 - 2Ω

±3% of scale length

x 10Ω

0 - 20Ω

4 - 9V DC

200mA DC min.

0.2Ω min.

Operating instrumetal uncertainty
  Insulation Resistance Ranges(IEC 61557-2)

Ranges
250V/100MΩ
500V/200MΩ
1000V/400MΩ

Measuring range to keep operating instrumetal uncertainty

0.1MΩ - 10MΩ

0.4MΩ - 40MΩ

Maximum percentage operating instrumetal uncertainty

±30%0.2MΩ - 20MΩ

  Continuity Test (Resistance Test) Ranges(IEC 61557-4)

Ranges
x1Ω
x10Ω

The influencing variations used for calculating the operating instrumental uncertainty are
denoted as follows:
Temperature : 0℃ and 35℃
Supply voltage : 6.5V to 10.4V
Position : Reference position ±90°
※Prior to measurement, apply Zero Adjustment at each position

Measuring range to keep operating instrumetal uncertainty

0.2Ω - 2Ω
2Ω - 20Ω

Maximum percentage operating instrumetal uncertainty

±30%

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Typical Number of Measurements (central tendency for supply voltage up to

Strap belt x 1
Test probe pouch x 1
R6P AA batteries x 6

Instruction manual x 1

6.5V)
  Insulation Resistance Ranges:
1000V/400MΩ Range Approx. 500 times min.
500V/200MΩRange Approx. 1300 times min.
250V/100MΩ Range Approx. 1800 times min.
  Continuity Test (Resistance Test) Ranges:
x1Ω Range/ x 10Ω Range Approx. 1000 times min.

Applicable Standards

IEC 61010-1. -2-030 Measurement CAT Ⅲ 300V Pollution Degree 2
 IEC 61010-031  Safety requirements for hand-held probe assemblies
 IEC 61557-1,2,4
 IEC 61326-2-2 EMC
 IEC 60529 (IP54) Dust & drip proof
 EN 50581 (RoHS)

Used location altitude 2000m or less
Operating Temperature & Humidity:
Storage Temperature & Humidity:
Insulation Resistance

Withstand Voltage 3470V AC for five seconds between electrical

Overload Protection

Insulation resistance ranges: 1000V Range 1200V (DC) for 10 seconds

500V Range  600V (DC) for 10 seconds

 Continuity ranges:

Dimensions: 185(L) x 167(W) x 89(D) mm approx.
Weight: 860g approx. (including batteries)
Power Source:
Accessories Test Probe MODEL7122B x 1 set

Measuring equipment for low voltage distribution systems

0-40℃, relative humidity up to 85%

Mo re tha n 50MΩat 1000V DC between
electrical circuit and housing case

circuit and housing case

250V Range
x 1Ω/ x 10ΩRange 440V (AC p-p) for 1minute

6 x 1.5V battery type SUM-3, R6 , AA or equivalent

-20-60℃, relative humidity up to 85%

300V (DC) for 10 seconds

Spare fuse F 500mA/600V x 1

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4. Instrument Layout

Fig.1 Part names

①METER MOVEMENT ZERO ADJUST ②TEST BUTTON
③SCALE PLATE ④LIVE CIRCUIT WARNING LED
⑤POWER-ON INDICATION LED ⑥CONTINUITY ZERO ADJUST
⑦LIGHT SWITCH ⑧RANGE SELECTOR SWITCH
⑨TEST PROBE (RED) LINE PROBE ⑩TEST PROBE (BLACK) EARTH PROBE
⑪ALLIGATOR CLIP (BLACK) ⑫PROTECTIVE FIGERGUARD

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Cap

Protective fingerguard：
It is a part providing protection against electrical shock and ensuring the minimum
required air and creepage distances.

Cap：
Uncapped condition for CAT.II environment
Capped condition for CAT.III/ IV environments
The Cap shuld be firmly attached to the probes.

Protective fingerguard

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5. Preparation for Testing

5-1 Removing the Cover

  Model 3131A has a dedicated cover to protect against an impact from

the outside and prevent the operation part, and the connector socket
from becoming dirty.

  Remove the cover and put it on the back side of the main body to make

measurements.

5-1-1 Method of removing the cover

Fig.2

5-1-2 Method of housing the cover

Fig.3

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5-2 Mechanical Zero Adjustment

  Check that the pointer lines up with the middle of the mark on the scale

correctly. If not, adjust it by rotating the meter movement zero adjust with
a screwdriver, etc.

5-3 Battery Voltage Check

① Set the range selector switch to BATT. CHECK position.
  ② Press the test button.
  ③ Then the pointer deflects. Judge the battery status with BATT.GOOD

mark on the scale plate.

  If the pointer does not move to BATT.GOOD mark, the batteries are

exhausted. Replace them with new batteries according to section 8 for
battery & fuse replacement.

5-4 Test Probe Connection

Insert the test probe fully into the terminal of the instrument.
  Connect the earth clip of the test probe (black) to EARTH terminal and

the line probe (red) to LINE terminal of the connector terminal.

5-5 Test Probe Check

  Set the range selector switch to x1Ω position and press and turn the Test

button to lock it down. When the test probe are connected together, the
pointer should move from the ∞ position towards the ０position on the
blue continuity scale. If not, the probe or fuse may be faulty. Release the
Test button after completion.

 # CAUTION

Do not keep the test button pressed or locked by turning it clockwise during
battery check.

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6. Operation

6-1 Disconnection and check of power source of circuit under test

DANGER

#

● To avoid possible electrical shock, do not perform measurements on

energized (LIVE) circuits.

● Never make measurements with the battery compartment cover removed.

● Always Keep your fingers and hands behind the protective fingerguard on

test probe to avoid the possible shock hazard.

CAUTION

#

● Never press the test button if the live circuit warning LED is lit or the

warning buzzer sounds. This may damage the circuit.

Voltage check can be made with the range selector switch at any position.
Be sure to turn off the breaker for the circuit under test.
① Connect the earth clip of the test probe (black) to the earth side and the line

probe (red) to the line side of the circuit under test.

② Ensure that the live circuit warning LED is not lit and the audible warning

is not present. If the LED is lit and the buzzer sounds, never press the test
button. Voltage is generated in the circuit under test. Recheck that the
breaker for the circuit under test is "OFF".

E L

Fig.4

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6-2 Insulation Resistance Measurement

 # DANGER

● Always test the circuit or equipment to ensure it is surely de-energized

before measurement according to the instruction of 6-1.
To avoid electrical shock, measurements must be performed on de-

●

energized circuits only.
When the test button is pressed with the range selector switch in the

●

insulation position, take care not to touch the tip of the test probe and the
circuit under test where a high voltage is present in order to avoid possible
shock hazard.

●

Never make measurement with the battery compartment cover removed.

● Always Keep your fingers and hands behind the protective fingerguard on

test probe to avoid the possible shock hazard.

 # CAUTION

● Never press the test button if the live circuit warning LED is lit or the

warning buzzer sounds. This may damage the circuit.

  Conduct the voltage warning check before measurement to ensure that

the circuit under test is de-energized.

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

the range selector switch to the desired nominal output voltage range.

② Connect the earth clip of the test probe (black) to the earth terminal of the

circuit under test.

③ Put the tip of the line probe (red) to the circuit under test and press the

test button.

④ Read the scale directly for the 500V range, multiply by 0.5 for 250V and

by 2 for 1000V.

Fig.5 Insulation resistance measurement

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 # DANGER

E

LINE（－）

E

Do not touch the circuit under test immediately after testing. Capacitance
stored in the circuit may cause electric shock.
Leave the test probe connected to the circuit and never touch the circuit until
the discharge is completed.

Principle of Insulation Resistance Measurement
  Resistance value can be obtained by applying a certain high voltage to the

resistance (insulation resistance) and measuring the flowing current.

Resistance Value = Voltage/Current
       RX = V/I

14

RESISTANC
VALUE:RX

CURRENT:I

—

VOLTAGE:V

ARTH（＋）

6-3 Continuity Testing (Resistance Tests)

DANGER

#

● Always test the circuit or equipment to ensure it is surely de-energized

before measurement according to the instruction of 6-1.

● To avoid electrical shock, measurements must be performed on de-

energized circuits only.
Never make measurement with the battery compartment cover removed.

●

● Always Keep your fingers and hands behind the protective fingerguard on

test probe to avoid the possible shock hazard.

 # CAUTION

● Never press the test button if the live circuit warning LED is lit or the

warning buzzer sounds. This may damage the circuit.

  Conduct the voltage warning check before measurement to ensure that

the circuit under test is de-energized.

● In case that an additional operating circuit is connected in parallel to the

circuit under measurement, the measurement error might be caused due
to the effects of impedance of the circuit conneted in parallel or transient
current.

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① Set the range selector switch to the desired position x 1Ωor x 10Ω.
② Short the line probe (red) and the earth clip of the test probe (black) and

press the test button. Adjust the ohm zero adjust to zero the pointer on
the scale.

③ Connect the test probes to the circuit under test and press the test button.
④ Read the scale directly for x 1Ωrange, multiply by 10 for x 10Ωrange.

Fig.6

Principle of Continuity Testing (Resistance Test)
  Resistance value can be obtained by applying a certain current to the

resistance under test and measuring the voltage generated on the both
sides of the resistance under test.

Resistance Value = Voltage/Current
       RX = V/I

6-4 Continuous Measurement

  A lock down feature is incorporated on the test button. Pressing and

turning it clockwise, lock the test button in the continuous operating
position.

  To release the lock turn the test button counterclockwise.

 # DANGER

Be extremely careful not to get electric shock during insulation resistance
measurement as high voltage is present on the tip of the test probe
continuously.

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7. Back Light Function

To facilitate working at night or dimly lit situations, a back light function is
provided which illuminates the display.
To operate this function, the back light button must be pressed and released
while pressing the test button. The back light continues illuminating for
approx. 40 seconds and then turn off automatically.
When the test button is released, the back light will turn off even within the
lighting time.

Fig.7 How to use the back light button

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SPARE FUSE

BATTERY

8. Battery & Fuse Replacement

 # DANGER

●  

Never open the battery compartment cover while making measurement.

   To avoid possible electrical shock, disconnect the test probe before

opening the cover for battery and fuse replacement.

●   Replacement fuse must have the following rating.
  Fast acting type, F500mA/600V, φ6.35×32mm

8-1 Battery Replacement

① Disconnect the test probe from the instrument.
  ② Open the battery compartment cover by unscrewing the metal captive

screw to reveal battery compartment. Always replace all six batteries
with new ones at the same time.

    Battery type: 6 x 1.5V battery type SUM-3, R6, AA or equivalent

8-2 Fuse Replacement

① Disconnect the test probe from the instrument.
  ② Open the battery compartment cover by unscrewing the metal captive

screw to reveal battery compartment and replace the fuse.

    Fuse type: F500mA/600V fast acting ceramic fuse φ6.35 x 32mm

  Install batteries in correct polarity as marked inside the case.

SCREW

FUSE

Fig.8 How to replace batteries and fuse

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9. Notes on Accessories

9-1 How to Fit Strap Belt and Test Probe Pouch

  By hanging the instrument around the neck, both hands can be used

freely for easy and safety working.

  ① How to fit the strap belt

Fig.9 How to fit the strap belt

  ② Whole diagram when the test probe pouch is attached

Fig.10 How to fit the test probe pouch

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10. Cleaning of the Instrument

◎ Cleaning the meter cover

  This instrument 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 instrument 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-static agent or detergent
to wipe the meter cover surface.

11. Service

If this tester should fail to operate correctly, return it to your nearest
distributors stating the exact nature of the fault.
Before returning the unit, make sure that:

a)   probes have been checked.
 b)   fuse has been checked.
 c)   battery has been checked.

Remember, the more information written about the fault, the quicker it will be
serviced.

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