Instruction manual
JIS approved product
KEW 3552/3552BT

INSULATION - CONTINUITY TESTERKEW 3551/3552/3552BT

Contents
1. Safety warnings (Safety precautions) ･･････････････････････････････････1
2. Features ････････････････････････････････････････････････････････････4
3. Specifications ･･･････････････････････････････････････････････････････7
4. Instrument layout ･･････････････････････････････････････････････････ 12
5. Accessories ･･･････････････････････････････････････････････････････ 15
6. Getting started ････････････････････････････････････････････････････ 16
6-1 Attaching metal tip/ adapter for test leads ･･･････････････････････ 16
6-2 Battery voltage check ･･････････････････････････････････････････ 17
7. Voltage measurement ･･････････････････････････････････････････････ 18
7-1 Measurement method ･･････････････････････････････････････････ 18
8 Insulation resistance measurement ･･････････････････････････････････ 20
8-1 Measurement method ･･････････････････････････････････････････ 21
8-2 Continuous measurement ･･････････････････････････････････････ 23
8-3 Voltage characteristics of measurement terminals ････････････････ 24
8-4 20G/ 40GΩ range (3552/3552BT only) ･･･････････････････････ 25
8-4-1 Settings ･･････････････････････････････････････････････････ 25
8-5 Insulation status indicator ･･････････････････････････････････････ 26
8-5-1 Reference value for insulation status, Pass/ Fail, judgement ･･･････････ 26
8-5-2 Reference value settings ･･････････････････････････････････ 27
8-6 DAR/ PI measurement, 1-min value display (KEW3552/3552BT only) ･････････ 29
8-6-1 DAR/ PI measurement and 1-min value display･･････････････ 29
8-6-2 Indication ････････････････････････････････････････････････ 29
9. Low resistance measurement (Continuity check) ･････････････････････ 30
9-1 Zero Ω ADJ. function ･･････････････････････････････････････････ 30
9-2 Measurement ･････････････････････････････････････････････････ 30
10. LCD backlight, LED light, Buzzer ･･････････････････････････････････ 31
10-1 LCD backlight ････････････････････････････････････････････････ 31
10-2 Buzzer ･･････････････････････････････････････････････････････ 32
10-3 Settings of backlight, LED light, and buzzer ････････････････････ 32
11. Auto-power-off ･･･････････････････････････････････････････････････ 35
12. Clock setting (KEW 3552/ 3552BT only) ･･････････････････････････ 36
12-1 Setting ･･････････････････････････････････････････････････････ 36

13. Memory function (KEW 3552/ 3552BT only) ･･････････････････････ 37
13-1 Saving method ･･･････････････････････････････････････････････ 37
13-2 Recalling the data ････････････････････････････････････････････ 38
13-3 Deleting the data ･････････････････････････････････････････････ 39
14. Infrared data transmission (KEW 3552/ 3552BT only) ･･････････････ 40
14-1 How to transfer data ･･････････････････････････････････････････ 40
15. Bluetooth communication (KEW 3552BT only) ･････････････････････ 41
15-1 Bluetooth communication ･････････････････････････････････････ 41
15-2 KEW Smart for KEW 3552BT･････････････････････････････････ 42
16. Battery replacement ･･････････････････････････････････････････････ 43
17. Shoulder strap belt attachment ････････････････････････････････････ 44
18. Storing in carrying case ･･･････････････････････････････････････････ 44

1. Safety warnings (Safety precautions)This instrument has been designed, manufactured and tested according toIEC 61010: Safety requirements for electrical equipment for measurement,
and delivered in the best condition after passing quality control tests. This
instruction manual contains warnings and safety rules which must be
observed by the user to ensure safe operation of the instrument and tomaintain it in safe condition. Therefore, read through these operating
instructions before starting to use the instrument.
# DANGER● Read through and understand instructions contained in this manual
before starting to use 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 theabove instructions may cause injury, instrument damage and/or damage toequipment under test. Kyoritsu is by no means liable for any damage
resulting from the instrument in contradiction to these cautionary notes.
The symbol # indicated on the instrument means that the user must refer tothe related parts in the manual for safe operation of the instrument. It isessential 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.
# DANGER● Do not apply voltages above 600 V, including voltage to earth, across theterminals of this instrument.
● KEW 3551/3552/3552BT are rated to CAT IV 300 V/ CAT III 600 V.
Do not make measurements under the circumstances exceeding thedesigned measurement categories.
● Do not attempt to make measurements in the presence of flammablegasses; otherwise, the use of the instrument may cause sparking, which
can lead to an explosion.

̶1̶

● Never attempt to use the instrument if its surface or your hand is wet.
● Be careful not to short-circuit a power line with the metal part of the test
lead during a measurement. It may cause personal injury.
● Never open the battery compartment cover during a measurement.
● The instrument should be used only in its intended applications orconditions; otherwise, safety functions equipped with the instrument don twork, and instrument damage or serious personal injury may be caused.
● Verify proper operation on a known source before use or take actions as aresult of the indication of the instrument.
# WARNING● Do not use the instrument or test leads if any abnormal conditions, suchas broken cover or exposed metal parts are noted.
● First, firmly connect the test leads to the instrument, and then press thetest button.
● Never install substitute parts or make any modifications to the instrument.
Send the instrument to your local KYORITSU distributor for repair or recalibration.
● Do not try to replace batteries if the surface of the instrument is wet.
● Connect each test lead firmly into the corresponding terminals.
● Stop using the test lead if the outer jacket is damaged and the inner
metal or color jacket is exposed.
● Ensure that the function switch is set to OFF position before opening thebattery compartment cover for battery replacement.
● Never turn the function switch while the test leads are connected to theequipment under test.
# CAUTION● Always make sure to set the function switch to the appropriate position
before making a measurement.
● Power off the instrument after use. Remove batteries if the instrument is
to be stored and won t be used for a long period.
● Do not expose the instrument to direct sunlight, high temperature,humidity or dew.
● Use a slightly damp cloth with neutral detergent or water for cleaning.
Do not use abrasives or solvents.
● This instrument isn t water-proof. Do not let the instrument get wet.
Otherwise, it may cause malfunction.
● If the instrument is wet, make sure to let it dry before putting it intostorage.
● Keep your hand and fingers behind the barrier during a measurement.

̶2̶Symbols
The following symbols are used and marked on the instrument and in this
instruction manual. Please carefully check before starting to use theinstrument.

Double or reinforced insulation
User must refer to the explanations in the instruction
manual.
Earth
Danger of possible electrical shock
Do not use on AC electric systems exceeding 660 V.
Complies with WEEE Directive (20 02/ 9 6/ EC)
marking requirements. (valid in each EU country)

Measurement Category
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 ameasuring instrument designed for CAT III environments can endure greater
momentary energy than one designed for CAT II.
O: Measuring circuits without a MEASUREMENT CATEGORY.
CAT II: Electrical circuits of equipment connected to an AC electricaloutlet by a power cord.
CAT III: Primary electrical circuits of the equipment connected directly
to the distribution panel, and feeders from the distribution panel
to outlets.
CAT IV: The circuit from the service drop to the service entrance, andto the power meter and primary overcurrent protection device(distribution panel).

̶3̶O: Measuring circuits
without a
MEASUREMENTCATEGORY.

2. Features
KEW 3551/3552/3552BT can measure insulation resistance, low resistance,
and also AC/ DC voltage.
● LCD backlight and LED spot light to facilitate working at dimly illuminatedlocation or at nighttime work. The built-in illuminance sensor automaticallyturns on/ off the lights.
● Memory function (available on KEW 3552/ 3552BT)Internal memory to save, recall, and delete the measured data.
● Infrared transmission function (available on KEW 3552/ 3552BT)
Transmits the data saved in the internal memory to PC.
● Bluetooth communication function (available on KEW 3552BT)
Connects the instrument and a Bluetooth device, like a tablet, for remotemonitoring and data saving.
● Clock (available on KEW 3552/ 3552BT)
Measured data is saved with the measurement time information.
● Auto power off function
Automatically powers off the instrument if there is no function change orbutton press for ten min.
● Voltage measurement with AC/ DC auto-detection● Insulation resistance measurement- Quick response
Shows the measured result in approx. 0.5 sec.
- With auto-discharge function
Automatically discharges electric charges stored in the capacitive circuit
when a measurement is finished.
- With insulation status indicator
LCD backlight color indicates whether a measured value is less than or̶4̶higher than the reference value.
- With elapsed time display
Starts counting and displaying testing duration, elapsed time, on the startof insulation resistance measurement.
- DAR/ PI measurement function (available on KEW 3552/ 3552BT)
Automatically calculates and displays DAR (Dielectric Absorption Ratio)
and PI (Polarization Index) values during an insulation resistancemeasurement.
● Zero-ohm adjustment function
For low-resistance measurements, short-circuit the tips of test leads andpress the 0ΩADJ button to cancel the resistance of the test leads itself.

̶5̶

Overview of available function list
Function

KEW 3551

KEW 3552

KEW 3552BT

O

O

O

---

O

O

Voltage measurement
20G/40GΩ
Range
Insulation
Meas.

Insulation statusindicator

Fixed Pass/ User selectable Pass/
Fail criteria Fail criteria

DAR/ PI---OO

Zero ADJ.

OOOContinuity buzzer

O

O

O

Backlight

O

OO

Memory

---

O

O

Clock

---

O

O

IR
(MODEL8212USB)

---

O

O

Wireless(via Bluetooth)

---

---

O

Lowresistance
Meas.

Data
Communication

̶6̶

3. Specifications● Measuring range and accuracy (at 23℃±5℃, 85%RH or less)
1. Voltage measurement
Range

300.0/ 600 V (auto-ranging)
AC

Display range

DC

300.0 V : 0.0 to 314.9 V
600.0 V : 270 to 629 V
300.0 V : ± 0.0 to ± 314.9 V
600 V : ± 270 to 849 V

Measuring range(accuracy guaranteed)

AC: 2.0 to 600 V rms (45 ‒ 65 Hz)
DC: ± 2.0 to ± 600 V

Over-range display

AC: > 629 V
DC (+) : > 849 V
DC (-) : < - 849 V

Accuracy±1%rdg±4dgt* RMS detection in AC mode. For non-sinusoidal waveforms with CF<2.5,
add ±1%rdg for the above listed accuracy. (850 Vpeak or less). AC/ DC
auto-detection (2 V or higher)
2. Low resistance measurement (Continuity check)
Resistance range

40.00/ 400.0/ 4000 Ω (auto-ranging)

Open-circuit V(DC)

5 V (4 - 6.9 V)

Measurement current

200 mA or more (2 Ω or less)

Display range

40.00 Ω : 0.00 - 41.99 Ω
400.0 Ω : 36.0 - 419.9 Ω
4000 Ω : 360 - 4199 ΩOver-range display> 4199 Ω

Measuring range
and accuracy

0.20 - 4000 Ω(to keep operating uncertainty)

0 - 0.19 Ω

±2.5%rdg±8dgt

±8dgt

̶7̶

3. Insulation resistance measurement

The otherranges

2nd effective
meas. range

1st effective
meas. range

500 V
1000 V
4/40/400/4000
4/40/400/2000
MΩ/40 GΩ*1
Range
4/40/100 4/40/200 4/40/250 4/40/400 MΩ/20 GΩ*1
(40 GΩ Range:(auto-ranging) MΩ
MΩ
MΩ/500 MΩ (20GΩ Range:
3552/3552BT only) 3552/3552BT only)
4 MΩ: 0.000 - 4.199 MΩ/ 40 MΩ: 3.60 - 41.99 MΩ
400 MΩ: 36.0 - 419.9 MΩ
Display
100 MΩ: 200 MΩ: 250 MΩ:2000 MΩ:
4000 MΩ:
500
MΩ:
range
36.0 ‒
36.0 ‒
36.0 ‒
360 - 2099 MΩ 360 - 4199 MΩ
360
524
104.9 MΩ 209.9 MΩ 262.4 MΩ
20 GΩ:
40 GΩ:
MΩ
1.80 - 20.99 GΩ 3.60 - 41.99 GΩ
KEW3551>2099 MΩ
>4199 MΩKEW3552/3552BT *1
O v e r - r a n g e >104.9>209.9>262.4>524
While 20/ 40GΩ Range is enabled:
displayMΩ
MΩ
MΩ
MΩ
(if disabled, the display is the sameas KEW3551)>20.99 GΩ
>41.99 GΩ
Open-circuit V
100 - 110 % of rated measurement voltage
Short-circuit A
within 1.5 mA
1.0 - 1.1 mA
Rated current@0.05 MΩ @0.1 MΩ @0.125 MΩ @0.25 MΩ
@0.5 MΩ
@1 MΩ

Accuracy (tolerance)

Rated V

50 V

100 V

125 V

250 V

0.100 0.100 ‒0.100 ‒
0.100 10.00 MΩ 20.00 MΩ 25.00 MΩ 50.0 MΩ

0.100 - 500 MΩ 0.100 -1000 MΩ

±2%rdg±2dgt
10.01 20.01
25.01 - 50.1 -500
501 ‒ 2000 MΩ 1001 - 4000 MΩ
100.0 MΩ -200.0 MΩ 250.0 MΩ
MΩ
±5%rdg0.050 - 0.099 MΩ: ±2%±4dgt
0.000 - 0.049 MΩ: ±2%rdg±6dgt
2.00 - 20.00 GΩ 4.00 - 40.00 GΩ----±5%rdg±0.4% per GΩ

Max. capacitive load: 1 uF: max. discharge value within a defined time
(10 sec.) after a test. (IEC61010-2-034)
Measurement capacitive load: 2 uF, capacitive load which falls within theva ri a t i o n s (±10 %) a t c a p a c i t i v e l o a dmeasurement test specified in IEC 61557-2.
*1
Voltage measurements on 20 GΩ and 40 GΩ ranges can be turned on/ off.
Please see 8-4 20G/ 40GΩ range in this manual.

̶8̶

● Applicablestandards● IEC 61010-1, -2-034 CAT IV 300 V/ CAT III 600 V
Pollution degree 2● IEC 61557-1, -2, -4, -10● IEC 61326-1, 2-2 (EMC)● IEC 60529 (IP40)● IEC 63000 (RoHS)● JIS C 1302
* KEW 3552/3552BT complies with JIS C 1302.
● IEC 61010-031
MODEL7260
CAT III 600 V (w/ cap)
CAT II 1000 V (w/o cap)
CAT II 1000 V (w/ 8017A)(Attach the supplied protective cap to use this test
leads in CAT III or higher environments.)
MODEL7261A
CAT III 600 V (w/ alligator clip)
CAT II 600 V (w/ flat test bar)
(Attach the supplied alligator clip to use this test
leads in CAT III or higher environments.)* When test leads, sometimes with metal tips, areconnected and used with the instrument, themeasurement category and voltage rating of thelowest rated item is applied.
● Location for use
Altitude 2000 m or less, in-door use● Nominal system V 600 V* Nominal voltage of distribution systems for which the
instrument is designed. (IEC 61557)● Operating temp. & -10℃ to +50℃, 80 % or less (no condensation)
humidity range● Storage temp. &-20℃ to +60℃, 75 % or less (no condensation)
humidity range● Communication
Bluetooth Ver. 5.0(KEW 3552BT only)● Withstand voltage 5160 V AC (50/ 60 Hz)/ 5 sec.
Between electrical circuit and enclosure● Insulation
50 MΩ or more/ 1000 V DC
Between electrical circuit and enclosure
resistance● Auto-power-off
The instrument turns off automatically, after a beepsound, if there is no function or range change, orbutton press for about 10 min.
● LCD backlight/
Automarically turns off if there is no activity for about
two min. (*disabled during a measurement.)
LED light● Dimension
97 (L) x 156 (W) x 46 (H) mm● Weight
Approx. 490 g (including batteries)● Power source
Four size AA batteries* Use of alkaline battery is recommended.

̶9̶

● Operating uncertainty
Operating uncertainty (B) is an error obtained under the nominal operating
conditions and calculated with the intrinsic uncertainty (A), which is anerror of the instrument used, and the error (En) due to variations.
According to the standard, IEC 61557, the maximum operating error
should be within ±30 %. Intrinsic uncertainty (A) is uncertainty of theperformance characteristics of the instrument in the reference condition.
1. Operating uncertainty of insulation resistance measurement (IEC 61557-2)* Formula: B = ±(|A|+ 1.15 x √E12 + E 22 + E 32)
A

Intrinsic uncertainty

E1 Influence of position (N/A for digital testers)
E 2 Influence of supply voltage(until battery status indicator becomes empty.)

E 3 Influence of temperature (0℃ - 35℃)
The specs. of this instrument are as follows.
Intrinsic uncertainty (A) .................. within ±5 % of indicated value(coverage factor: k=2)
Influence of supply voltage (E 2).... within ±5 % of indicated value
Influence of temperature (E 3) ........ within ±5 % of indicated value
Max. operating uncertainty (B) ..... 14 %* The measuring range to keep the max. operating uncertainty is the same as
the 1st effective measuring range.
2. Operating uncertainty of low-resistance measurement (IEC61557-4)* Formula: B = ±(|A|+ 1.15 x √E12 + E 22 + E 32)
A

Intrinsic uncertainty

E1 Influence of position (N/A for digital testers)
E 2 Influence of supply voltage(until battery status indicator becomes empty.)

E 3 Influence of temperature (0℃ - 35℃)
* Measuring range to keep the max. operating uncertainty (within ±30%) is
0.2 to 4000 Ω.

̶ 10 ̶

● Possible number of measurements where battery voltage is within theeffective range. (measurement of 5 sec., pause of 25 sec.)
Measurement function Test resistor

Possible number of measurements

50 V

0.050 MΩ

2000 times or more

100 V

0.100 MΩ

1600 times or more

125 V

0.125 MΩ

1600 times or more

250 V

0.25 MΩ

1300 times or more

500 V

0.5 MΩ

1300 times or more

1000 V

1 MΩ

700 times or more

1Ω

1400 times or more

Insulation
ResistanceLow resistance* where:using alkaline batteries, disabling the backlight, and disabling insulation
status indicator.

̶ 11 ̶

4. Instrument layout
1. Front panel

①
②
③
④

⑥

⑤
① LCD

Name

② Illuminance sensor③ Test button④ Optical adapter⑤ MEMORY button⑥ Cursors⑦ ESC button⑧ ENTER button
0ΩADJ button⑨ KEW3551: COMP button（

KEW3552/ 3552BT:
SETUP button⑩ SELECT button⑪ Function switch⑦ ⑧⑨ ⑩⑪

Fig.4-1

Description
LCD with backlight
Detects ambient brightness and automatically turns on/
off the lights.
Starts/ stops measurement. For continuous measurement,press and turn the button clockwise to lock it in theoperating position.
To connect MODEL8212USB and transmit data to a PC.
A short press (< 1 sec.) to save the measured value whilethe value is being held and displayed.
A long press ( 1 sec.) to read-out or delete the saved
data while the instrument is in stand-by mode.
Alters, increases/ decreases, the user selectable values.
Returns to the previous screen or closes the setting screen.
Confirms a selection.
Turns on/ off the 0Ω ADJ function at low resistancemeasurement.
* For KEW 3551: also used to turn on/ off insulation status indicator.
* For KEW 3552/ 3552BT: also used to make settings of each function.
A long press ( 1 sec.) while measuring 125 V switches ameasurement range to 100 V range; a short press (<1 sec.)
at voltage measurement switches the function to low
resistance measurement.
Switches measurement functions and selects voltage forinsulation resistance measurement.

）* KEW 3551 doesn t have ④ to ⑧ buttons.

̶ 12 ̶

2. Side panel③

Fig. 4-2

①

②

Name

Description① LINE terminal

To connect MODEL7260 test lead.

② EARTH terminal

To connect MODEL7261A test lead.

③ LED spot light

Illuminates the measurement spot. The light automatically turns on/ off depending on the ambient
brightness.

3. LCD

Fig. 4-3
Name

Description
Battery status indicator
Bar graph display of insulation resistance
Digital display with measurement unit
Memory No., elapsed testing time, thresholdvalue for PASS/ FAIL, 1-min value, and DAR/ PI
valuesAppears to show the measured value is being held.
Appears and blinks while measuring insulation
resistance and for live circuit warning.

̶ 13 ̶

> symbol appears when the measured value is
exceeding the measuring range, and < symbol
appears when the measured dc has negative polarity.
Appears when 0ΩADJ is done.
Appears at Bluetooth communication (3552BT only)
Buzzer ON
Appears at IR communication (3552/ 3552BT only)
Blinks while adjusting time (3552/ 3552BT only)
Indicates a DAR value is displayed. (3552/ 3552BT
only)
Indicates a PI value is displayed. (3552/ 3552BT
only)
Indicates 1-min value is displayed.
Comparator function is enabled.
Indicates the rated measurement voltage value
selected at insulation resistance measurement.
Indicates the measured insulation resistance value
exceeds the pre-set threshold value.
Measured insulation resistance value is less than thethreshold value.
Appears while accessing the internal memory.
(3552/3552BT only)
Appears during a voltage measurement: AC for ac
voltage, DC for dc voltage, and minus symbol for
negative dc voltage.

̶ 14 ̶

5. Accessories● Test leads(1) Teat lead with remote control switch MODEL7260 (red)*1 Barrier
Metal tip

Attach the supplied detachable
cap as necessary.
For CAT III 600 V (w/ cap)
For CAT II 1000 V (w/o cap)

Insulation cap
Fig. 5-1(2) Extension prod long MODEL8017A* Attached and used with MODEL7260.
Long type and helpful to accessthe distant measurement spot

Fig. 5-2(3) A set of test lead with alligator clip MODEL7261A
Black cable with banana plugs at both ends

L-shaped
Banana plug

Alligator clip

*1 Protective
fingerguard

Flat test bar*1 Protective
fingerguard

Fig. 5-3* 1 Protective fingerguard is a part providing protection against electrical shockand ensuring the minimum required clearance and creepage distances.
● Other accessories(1) Carrying case MODEL9173(2) Shoulder strap MODEL9121(3) Four AA alkaline batteries(4) Instruction manual

̶ 15 ̶

6. Getting started
6-1 Attaching metal tip/ adapter for test leads
The following metal tips and adapters are user-changeable depending on
measurement purposes.
(1) For MODEL7260
The following metal tips are available.
1. Standard metal tip........ I n stalle d at a s hip m e nt s u p plie d wit h a
detachable insulation cap.
2. MODEL8017A ............. Long type and helpful to access the distant point.
[How to replace the parts]
Turn the tip of MODEL7260 counter-clockwise and remove the metal tip.
Insert the metal tip you want to use into the hexagon hole, and turn the tip
part of the probe clockwise to tighten firmly.

(2) For MODEL7261A
Either of the following adapters can be attached to.
1. Alligator clip
2. Flat test bar

̶ 16 ̶

# DANGER
To avoid getting electrical shocks, disconnect the test leads from the
instrument before replacing the metal tip or adapter.
6-2 Battery voltage check(1) Please refer to 16. Battery replacement in this manual and insert batteries
in the instrument.
(2) Set the function switch to any position other than OFF to power on the
instrument.
(3) Check the battery status indicator displayed at the upper left corner of the
LCD.
: Normal. Battery voltage is enough.
: Low battery voltage：For continuous measurement, please referto 16. Battery replacement and replace the batteries with newones.
: Battery voltage is below the lower limit of the operating voltage.
In such a condition, accuracy of the measured result isn tguaranteed. Replace the batteries with new ones immediately.
● Battery status indicator might change fromtoduring ameasurement depending on measured objects; for example, resistance ofthe object is low.
● Use of AA alkaline battery is recommended. Using other type of batteries
may cause improper indication of battery level.

̶ 17 ̶

7. Voltage measurement# DANGER● Do not apply a voltage exceeding the measuring range, 600 V max., to the
instrument.
● Keep your fingers behind the barrier during a measurement.
● Verify proper operation on a known source before taking actions as aresult of the indication of the instrument.
7-1 Measurement method(1) Set the function switch to V/ Ω position. To measure low resistance, press
the SELECT button (< 1 sec).
(2) Connect the test leads as the following figure shows.
- MODEL7260 to the LINE terminal- MODEL7261A to the EARTH terminal

Red

Black

Fig. 7-1(3) Connect the black test lead to the earth side of the circuit under test andthe red remote probe to the line side.

CAUTION
Never press the
remote-control switch.

CAUTION
Never press thetest button.

Select V/ Ω Range.

Fig. 7-2

̶ 18 ̶

(4) Check the reading on the LCD without pressing the test button nor remotecontrol switch. The instrument detects ac/ dc automatically, and shows
DC for dc input and AC for ac input.
● When negative dc voltage is defected at the line probe side, minus- polarity sign is displayed with a measured value.
● If the measured voltage is less than 2 V, AC/ DC auto-detection doesn t
work.
Note:
If the measured value exceeds the display range (over-range), the LCD
shows :
>629 V : for ac voltages,>849 V : for positive dc voltages, and<-849 V : for negative dc voltages.

̶ 19 ̶

8 Insulation resistance measurement
This instrument is used to measure insulation resistance of electric applianceor circuit to inspect the insulation performance. Check the voltage rating of
the circuit to be tested before making measurement and select the voltage
applied to.
Note:● Depending on the circuit to be measured, displayed insulation resistancevalue may not stabilize.
● Buzzer may sound during an insulation resistance measure-ment, however,this is not a malfunction.
● Measurement time may be longer when measuring a capacitive load.
● In insulation resistance measurement, the earth terminal outputs positive
voltage and the line terminal negative voltage.
● Connect the earth lead to the earth (ground) terminal at measurement. It is
recommended to connect the positive side to the earth side whenmeasuring insulation resistance against ground or when a part of the object
under test is earthed. Such connection is known to be more suitable forinsulation testing since insulation resistance values measured with thepositive side connected to earth are typically less than those taken throughthe reversed connection.
# DANGER● Be extremely careful not to touch the tip of test probe or the circuit under
test to avoid electrical shock during insulation measurement since highvoltage is present at the tip of the test probe continuously.
Wipe the test probe with a soft cloth, if it is wet, and use it after it s dry.
● The battery compartment cover must be closed before you operate theinstrument.
# CAUTION
Always disconnect power to the equipment under test before starting
insulation measurement. Do not attempt to make measurements on a live
circuit; otherwise, it may damage the instrument.

̶ 20 ̶

8-1 Measurement method(1) Connect the test leads as the following figure shows.
- MODEL7260 to the LINE terminal- MODEL7261A to the EARTH terminal

Red

Black

Fig. 8-1(2) Confirm that the circuit under test isn t energized, and measure voltage
with reference to 7. Voltage measurement.
(3) Confirm the voltage value which can be applied to the circuit under test,
and then set the function switch to the desired range.
● There is an empty range between 500 V and 1000 V ranges for safety
purpose. The instrument doesn t start a measurement even if the test
button is pressed while the function switch is set to this safety position.
● Discontinuous warning buzzer sounds when the function switch is set
to 1000 V range.
● To select 100 V range, set the function switch to 125 V/ 100 V
position, and then press the SELECT button 1 sec. or longer.
(4) Connect the black earth test lead to the earth terminal of the circuit under
test. If a voltage of 30 V or higher exists in the circuit, the LCD backlightappears with audible
blinks red and blinking live warning symbol
buzzer. While this warning function is activating , no resistancemeasurement can be made even if the test button is pressed.
(5) Place the tip of red test lead (line) to the circuit under test, and press thetest button or remote switch.
● Measurement time, elapsed time, is displayed on the LCD during
insulation resistance measurement: up to 99 min. 59 sec. by 1 sec.
Note: The time counter stops and freezes when it reaches to 99 min.
59 sec.; if the elapsed time exceeds 100 min.

̶ 21 ̶

Earth terminal

Source side
Circuit breaker

Black

Red
Load side

Fig. 8-2

Indicates the elapsed time.

Fig. 8-3(6) Auto discharge function
This function allows electric charges stored in the capacitance of the circuitunder test to be automatically discharged after measurement. Set the test
button or remote-control switch to off with the test leads connected.
symbol and buzzer, and red
Discharge can be checked with the blinking
blinking LCD backlight.
# DANGER
Never touch the circuit under test immediately after measurement.
Capacitances stored in the circuit may cause electric shock. Leave the test
leads connected to the circuit, and do not touch the circuit until blinking
goes off.
(7) Power off the instrument when measurement completes and disconnect
the test leads.
● The instrument holds the measured value display when a measurement
completes. You can save the result in the internal memory in this state(3552/3552BT only). For the detail of memory function, please refer to
13. Memory function. The held display can be released by turning thefunction switch or starting another measurement.

̶ 22 ̶

● Bar graphDepending on the selected measurement range, values on each tick of bar
graph vary as shown below.
Bar graph for
500 V/ 1000 V range

Fig. 8-4
Bar graph for 50 V/ 100 V/
125 V/ 250 V range

Fig. 8-5

8-2 Continuous measurement
For continuous measurement, use the lock-down feature incorporated on thetest button. Pressing and turning the test button clockwise locks the button in
the operating position. Turning counter-clockwise unlock the button.
# DANGER
Be extremely careful not to touch the tips of test leads to avoid getting
electrical shock since high voltage is present continuously.

̶ 23 ̶

8-3 Voltage characteristics of measurement terminals
This instrument conforms to IEC 61557. This standard defines that the rated
measurement current shall be at least 1 mA, and the lower limit of theinsulation resistance maintaining the rated measurement voltage atmeasurement terminals. (See the table below.) This value is calculated by
dividing the rated voltage by rated current. ie., in case that the rated voltage is
500 V, the lower limit of the insulation resistance is found as follows.
Divide 500 V by 1 mA equals 0.5 MΩ.
That is, insulation resistance of 0.5 MΩ or more is required to provide therated voltage to the instrument.
500V

1000V

Lower limit of theinsulation resistance
0.05 MΩ 0.1 MΩ 0.125 MΩ 0.25 MΩ 0.5 MΩ
to provide the rated
current of 1 mA

50V

100V

125V

1 MΩ

250V

Range

Output voltage (V)Rated voltage

Range

Output voltage (V)Insutation resistance (MΩ)

Fig. 8-6

Range

Range
Range
Range

Insutation resistance (MΩ)̶ 24 ̶

Fig. 8-7

8-4 20G/ 40GΩ range (3552/3552BT only)
The 20GΩ and 40GΩ ranges are available for measuring 500 V and 1000 V
respectively. (This is NOT available on KEW 3551.)
Enabling/ disabling 2 0 GΩ/ 4 0 GΩ range affects and changes theconfigurations of 500V and 1000V ranges as shown in the following table.
1. While 20GΩ/40GΩ ranges are disabled (default settings):
Voltage

Four measurement ranges

500V

4.000 MΩ/ 40.00 MΩ/ 400.0 MΩ/ 2000 MΩ

1000V

4.000 MΩ/ 40.00 MΩ/ 400.0 MΩ/ 4000 MΩ

2. While 20GΩ/40GΩ ranges are enabled:
Voltage

Five measurement ranges

500V

4.000 MΩ/ 40.00 MΩ/ 400.0 MΩ/ 2000 MΩ/ 20 GΩ

1000V

4.000 MΩ/ 40.00 MΩ/ 400.0 MΩ/ 4000 MΩ/ 40 GΩ

8-4-1 Settings(1) To enable measurements on 20GΩ/ 40GΩ range:
1. Get the instrument into setting mode.
2. Set the function switch to any position other than low-resistancemeasurement, and then hold down the SETUP button ( 2 sec.) whilein the stand-by mode.
3. Use the cursor key and toggle the screens for 20GΩ/ 40GΩ range
setting. The LCD shows 40GΩ and indicates the current setting withblinking on or oFF .

Light up

Blink

Fig. 8-8(2) Press the ENTER to switch on and oFF .

Fig. 8-9

Fig. 8-10(3) Press the ESC button to save the changed settings and the instrument
returns to stand-by mode. (The changes you made won t be cleared evenafter powering off the instrument.)

̶ 25 ̶

8-5 Insulation status indicator
8-5-1 Reference value for insulation status, Pass/ Fail, judgement
The instrument can compare the measured insulation value and the pre-set
reference value listed below. LCD backlight lights up and buzzer sounds
according to the result. This function can be turned off.
With KEW 3552/ 3552BT, you can select any desired value as a reference
value; the reference values are fixed and unchangeable on KEW 3551 .
● Reference values for KEW3551
Rated voltage

50V

100V

125V

250V

500V

1000V

Referencevalue (Ω)

0.1M

0.1M

0.125M

0.25M

0.5M

1M

These reference values are determined based on the resistance value toprovide 1 mA with the rated voltage. The color of LCD backlight indicates theresult as follows.
Compared result

LCD backlight color

exceeding the reference value

Solid green

reference value or less

Solid redFig. 8-12

Fig. 8-11

When a measured value is higher than
the reference value:“PASS”symbol
appears, and green LCD backlight lights
up.

When a measured value is equal to or
lower than the reference value:“FAIL”
symbol appears, and red LCD backlight
lights up.

̶ 26 ̶

8-5-2 Reference value settings
To turn off this status indicator function or alter the reference value to any
desired value (available only on 3552/ 3552BT), follow the procedures
described below.
* The setting procedures depend on each model. Please refer to the
explanation about the model you re using.
[KEW 3551](1) Set the function switch to the insulation resistance range you wish to set
the reference value.
(2) Press the COMP button to toggle the values. The currently selected
settings can be checked on the LCD indications.

Fig. 8-13

Fig. 8-14

Insulation status indicator is ON.
The LCD shows“COMP”and
the reference value.

Insulation status indicator is OFF.
No“COMP”nor reference value
are displayed.

(3) You can set this status indicator to ON or OFF for each range, respectively.
(The settings won t be cleared even after powering off the instrument.)[KEW 3552/ 3552BT](1) Get the instrument into setting mode.
1. Set the function switch to any position other than low-resistancemeasurement, and then hold down the SETUP button ( 2 sec.) instand-by mode.
2. Use the cursor key and select the range to set the reference value.

“”and the selected
range blink.

Fig. 8-15

3. Press the ENTER button.

“”and the reference
value start blinking.

Fig. 8-16

̶ 27 ̶

(2) Press the cursor key to toggle the reference values. Press the ENTER
button to set and save the displayed value as a reference value. The
following values are selectable.
SelectablevaluesOFF, 0.100 MΩ, 0.125 MΩ, 0.200 MΩ, 0.250 MΩ, 0.400
MΩ, 0.500 MΩ, 1.000 MΩ, 10.00 MΩ, 100.0 MΩ, Any(Selectable range: 0.000 MΩ ‒ 4199 MΩ)

Select Any to set your desired value as a reference value:

1. Select the place of decimal
point with cursor key, andpress ENTER to conﬁrm.

Fig. 8-17

2. Determine the value for ones
place, and press ENTER to
conﬁrm.

Fig. 8-18

3. Determine the value for tenths
place, and press ENTER to
conﬁrm.

Fig. 8-19

4. Determine the value for
hundredths place, and press
ENTER to conﬁrm.

Fig. 8-20

5. Determine the value forthousandths place, and press
ENTER to conﬁrm.

Fig. 8-21

To go one step back, press the ESC button.
symbol and range indication start blinking, it means theWhensettings are completed.
(3) Press the ESC button when settings complete. The selected reference
values are saved, and the instrument returns to stand-by mode.
(The saved reference values won t be cleared even after powering off the
instrument.)

̶ 28 ̶

8-6 DAR/ PI measurement, 1-min value display (KEW 3552/3552BT only)
8-6-1 DAR/ PI measurement and 1-min value display
The instrument can measure and calculate DAR (Dielectric Absorption Ratio)
and PI (Polarization Index) values automatically during an insulation resistancemeasurement. (not available on KEW 3551)● The DAR value is displayed in 1 minute and the PI value in 10 minutes
after starting a measurement.
● The following table shows the formula and display range.
DAR =FormulaPI =Resistance value (1 min after a start of test)
Resistance value (15 sec after a start of test)
Resistance value (10 min after a start of test)
Resistance value (1 min after a start of test)

Display range

0.00 - 9.99

* If a denominator, the measured resistance, used in the above formula is 0MΩ; the LCD shows no for DAR/ PI value. When the calculated DAR/PIvalues exceed the display range, the LCD shows >9.99 .
8-6-2 Indication
Press the cursor key, in 1 min. after starting a measurement, to check 1-minvalue or DAR/ PI values. (Please wait at least 10 min. to check PI value.)
The following indications show what value is currently displayed.

●1-min value:“”symbol and themeasured value.

Fig. 8-22●DAR value:“”symbol and the DAR value.
Fig. 8-23●PI value:
symbol and the PI value.
“”
Fig. 8-24

̶ 29 ̶

9. Low resistance measurement (Continuity check)# DANGER
Do not apply voltage to the low resistance range. Always check the circuit orequipment under test is surely de-energized before starting a measurement.
9-1 Zero Ω ADJ. function
This function is to null the resistances (up to 3 Ω) of the test lead or internal
circuit to display the resistance of the equipment under test only.
Setting:(1) Set the function switch to V/ Ω position.
(2) If the instrument is in the voltage measurement mode, press the SELECT
button (< 1 sec) and switch the mode to low-resistance measurement.
(3) Short-circuit the test leads: red lead connected to LINE terminal and black
lead connected to EARTH terminal.
(4) Press the 0ΩADJ button while the test button is locked or the remote
symbol.
control switch is held. Then the LCD shows 0.00 Ω with
The nulled value is saved and won t be cleared even after powering off the
instrument.
(5) To clear this nulled value, keep the test leads open-circuit status and press
disappears.
the 0ΩADJ button (short press). The symbol● This 0 ADJ. function doesn t work if the reading is 3 Ω or higher; theLCD shows no even the 0ΩADJ button is pressed.
9-2 Measurement(1) Set the function switch to V/ Ω position.
(2) If the instrument is in the voltage measurement mode, press the SELECT
button (< 1 sec) and switch the mode to low resistance measurement.
(3) Connect the test leads to the circuit to be measured and press the test
button or remote-control switch.

̶ 30 ̶

Fig. 9-1

● If a current of 200 mA or higher is detected on the object under test, thecontinuity buzzer sounds to indicate that there is continuity. If you wish todisable this continuity buzzer, please refer to 10. LCD backlight, LED light,
Buzzer.
● At low resistance measurements, impedances of the operating circuit
connected in parallel with the instrument may affect the measurement result.
● Circuit protection
The instrument has circuit protection function: even if touching with a live
circuit during low resistance measurement unintentionally, the instrument
will have no damage. That is, the instrument is protected and not bedamaged if the open measuring terminals are connected to a live wire.

10. LCD backlight, LED light, Buzzer
10-1 LCD backlight
Illuminance sensor
The illuminance sensor on this instrument detects
ambient brightness and automatically turns on/ off
the LCD backlight and LED light. Once these lights
turn on, they stay on for about 15 sec. This autolighting function can be set to always off.
● Keep the surface of the illuminance sensor
clean to ensure proper detection of brightness.
Fig. 10-1● The sensitivity of the sensor isn t adjustable.
Cover the sensor with your finger to turn on the lights manually.
● Even if working in dimly lit area, these lights turn off automatically if thefunction switch isn t operated or the test button isn t pressed for two
minutes. (These lights don t turn off automatically during a measurement orwhile live circuit warning is activating.)

̶ 31 ̶

10-2 Buzzer
Buzzer sounds when:
1. powering on the instrument,
2. turning the function switch or pressing any button,
3. measured current is 200 mA or higher at low resistance measurement,(Continuity buzzer)
4. selecting 1000V range,
5. live circuit warning is activating, and
6. auto-power-off function is activated.
* For the cases 1. to 3., the buzzer can be set to always off.
10-3 Settings of backlight, LED light, and buzzer
Follow the procedures described on the following pages and change thesettings ‒ turning on/ off ‒ of the lights and buzzer.
* The procedures depend on each model. Please refer to the explanation
about the model you re using.

̶ 32 ̶

[KEW 3551](1) Get the instrument into setting mode.
1. Ensure that the instrument is powered off. Hold down the 0ΩADJ
button.
2. Keep the 0ΩADJ button held down, and set the function switch to V/Ω position. The instrument wakes up and the LCD segments start
blinking to indicate now the instrument is in setting mode.

2. Set the function switch
to V/Ω position.
1. Hold down the 0 ΩADJ button; do not release it.

Fig. 10-2(2) Press the SELECT button to toggle the settings. The settings are toggled
in the following sequence: 1 -> 2 -> 3 -> 4 ->1.
Settings
Buzzer
LCD backlight/
LED light

1
ON

2
OFF

ON

ON

Mode

3
ON

4
OFF

OFF

OFF

The buzzer symbol and LCD backlight indicate the currently selected mode.
● Buzzer:
Blinking buzzer symbol means ON , no symbol means OFF .
● LCD backlight/ LED light:
Blinking backlight means ON ; if not, it means OFF . The on oroFF indication is also displayed at the lower left of the LCD accordingly.

Blinks when buzzer
is ON.

Blinks when LCD
backlight/ LED lightare ON.

Fig. 10-3

When LCD backlight/LED lights are set
to ON,“on”appears, and“oFF”appears
when these lights are set to OFF.

̶ 33 ̶

(3) Power off the instrument when setting completes. (The latest settings are
saved and won t be cleared even after powering off the instrument.)[KEW 3552/ 3552BT](1) Get the instrument into setting mode.
1. Set the function switch to any position other than low-resistancemeasurement, and then hold down the SETUP button ( 2 sec.) while inthe stand-by mode.
2. Use the cursor key and toggle the screens for backlight and buzzer
setting; the following figures shows each setting screen.

Backlight setting screen:.
The LCD shows“ bL”
Blink
Fig. 10-4

Buzzer setting screen:
The LCD shows“ ”symbol.
Blink
Fig. 10-5(2) Press the ENTER button to toggle the settings. The currently selected
setting can be checked by on or oFF indication shown in the LCD.

Fig. 10-6

Fig. 10-7(3) The instrument exits from the setting mode by pressing the ESC button.
The changes you made are saved and won t be cleared even after
powering off the instrument.

̶ 34 ̶

11. Auto-power-off
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 with audible buzzer sound. To turn on the instrument, turn thefunction switch to OFF position first, then set it to the desired range.
This auto-power-off function doesn t work during a measurement or Bluetooth
data communication. (KEW 3552BT only)̶ 35 ̶

12. Clock setting (KEW 3552/ 3552BT only)This instrument has an internal clock and can save the measured data withtime information. (Not available on KEW 3551.)
12-1 Setting(1) Get the instrument into setting mode.
1. Set the function switch to any position other than low resistancemeasurement, and then hold down the SETUP button ( 2 sec.) whilein the stand-by mode.
3. Use the cursor key and toggle the screens for clock setting; blinking
appears on the LCD.

Blink
Fig. 12-1(2) Press the ENTER button and adjust time and date according to thefollowing sequences.

1. Use the cursor key to adjust
the last two digits of year,
and conﬁrm with the ENTER
Blink
button.

AdjustFig. 12-2

2. Use the cursor key to adjust
the month and date, andconﬁrm with the ENTER
Blink
button.

AdjustFig. 12-3

3. Use the cursor key to adjust
the current time, andconﬁrm with the ENTER
Blink
button.

AdjustFig. 12-4

To go one step back, press the ESC button.
appears after step 3.
Setting completes when blinking
described above.
(3) Pressing the ESC button saves the changes you made and the instrument
returns to stand-by mode. The changes you made are saved and won t becleared even after powering off the instrument.

̶ 36 ̶

13. Memory function (KEW 3552/ 3552BT only)This instrument can save voltage, insulation resistance, and low resistancemeasurement results in the internal memory, 1000 results max. Data can besaved with two different site number for easy recognition. (Not available on
KEW 3551.)● Data to be saved:
Measured voltage, insulation resistance, and low resistance, DAR/ PI,
1-min value, time and date, measurement function, and the data and site
no. selected when saving the result.
● Data can be recalled:
Measured voltage, insulation resistance, and low resistance values,
measurement function, and the data no. and site no. selected at saving theresult. To check DAR/ PI value, 1-min value, time and date information, youneed to transfer the data to PC. Please refer to 14. Infrared datatransmission for further detail.
Items saved with themeasured result

Details

Selectable
range

Data No.

Select and assign a number for thedata to be saved. The number will be
automatically increased by 1.

0 - 999

SITE No.1(Site No. 1)
SITE No.2(Site No. 2)

Select and assign any number for themeasurement data. (depending on thebuildings or circuits)

0 - 990 - 9913-1 Saving method(1) Measured result is displayed and being held when a measurement
completes. (As for voltage measurement, data can be saved during ameasurement.)

Indicating the datahold status.
Fig. 13-1(2) Press the MEMORY button (< 1 sec.).

̶ 37 ̶

(3) Use the cursor key andselect SITE No. 1 , andpress the ENTER button toconfirm.

Blink(4) Use the cursor key andselect SITE No. 2 , andpress the ENTER button toconfirm.

Fig. 13-2

Blink

Fig. 13-3(5) Use the cursor key to selectthe Data No. , and press the
ENTER button to confirm.
(Data No. is updated
automatically.)
Blink

Fig. 13-4(6) When data saving completes, the instrument shows stand-by screen.
Press the ESC button to modify and re-do the settings.
● Simplified operation
You can skip SITE No. 1, and 2 and Data No. settings and save thedata just by pressing the MEMORY button in steps (3) - (5). In thiscase, SITE No. 1, and 2 used at the previous saving are used, andData No. is automatically increased by 1.
13-2 Recalling the data
(1) Hold down the MEMORY button ( 1sec.) in stand-by mode.
(2) Use the cursor key to switch the Data no.

Fig. 13-5

Blink(3) Press the SELECT button to show the SITE No. again. Another press of
the SELECT button returns to the measured value display screen.
(4) Press the ESC to return to the stand-by mode.

̶ 38 ̶

13-3 Deleting the data
(1) Hold down the MEMORY button ( 1sec.) in stand-by mode, and recall the
saved data.
(2) Use the cursor key to select the data no. you wish to delete. To delete all
the saved data, select ALL . ( ALL is displayed between 0 and
999 .)

Wishing to delete
all the saved data.

Fig. 13-6(3) The LCD shows clr by pressing the ENTER button. Another press of
ENTER deletes the selected data. Press the ESC button to return to theselection screen.

Data no. to bedeleted blinks.

Fig. 13-7(4) Press the ESC button to return to stand-by mode.

̶ 39 ̶

14. Infrared data transmission (KEW 3552/ 3552BT only)
The internal memory data can be transferred to PC by using the opticaladapter MODEL8212 USB. (Not available on KEW 3551.)
14-1 How to transfer data
(1) Ensure that the special application KEW Report has been installed inyour PC.
(2) Disconnect the test leads from the instrument.
(3) Connect MODEL8212 USB to the USB port of the PC.
(4) Open the cover for optical adapter and connect MODEL8212USB. Please
see Fig. 14-1 and 14-2 shown below.
(5) Power on the instrument. You can set the function switch to any position.
(6) Start KEW Report on your PC and click Download to start data
download. For further detail, please refer to the instruction manual for
MODEL8212 USB or HELP for KEW Report.

Fig. 14-2

Fig. 14-1

̶ 40 ̶

15. Bluetooth communication (KEW 3552BT only)
15-1 Bluetooth communication
KEW3552BT has a Bluetooth communication function and can exchange
data with Android/ iOS tablet devices. (Not available on KEW 3551/ 3552.)
Before starting to use this function, download the special application KEW
Smart for KEW3552BT via the internet.
Some functions are available only while connected to the internet. For further
detail, please refer to 15-2. KEW Smart for KEW 3552BT.
# WARNING
Radio waves at Bluetooth communication may affect the operations of
medical electronic devices. Special care should be taken when using
Bluetooth connection in the areas where such devices are present.
Cautions:● Using the instrument or tablet devices near wireless L AN devices( I E E E 8 0 2 .11. b/g) m ay c a u s e ra dio inte r fe re n c e s , lowe rin g ofcommunication speed, resulting in significant time lag in the display update
rate between the instrument and tablet device. In this case, keep the
instrument and the tablet device away from the wireless LAN devices, orturn off the wireless LAN devices, or shorten the distance between the
instrument and the tablet device.
● It may be difficult to establish communication connection if either the
instrument or tablet device is in a metal box. In such a case, change themeasurement location or remove the metal obstacle between the
instrument and the tablet device.
● If any leaking of data or information occurs while making a communication
using Bluetooth function, we assume no responsibility for any released
content.
● Some tablet devices, even if the application runs properly, may fail toestablish communication with the instrument. Please use another tablet
device and try to communicate with. If you still cannot confirm theconnection, there may be some problem with the instrument unit. Pleasecontact your local KYORITSU distributor.
● The Bluetooth word mark and logos are owned by Bluetooth SIG, Inc. and
we, KYORITSU, are licensed by them for use.
● Android, Google Play Store, and Google Maps are the trademark or
registered trade mark of Google Inc.
● iOS is the trademark or registered trade mark of Cisco.
● Apple Store is the service mark of Apple Inc.
● In this manual, the TM and ® marks are omitted.

̶ 41 ̶

15-2 KEW Smart for KEW 3552BT
The special application KEW Smart for KEW 3552BT is available on
download site for free. (An Internet access is required.) Please note that
communication charge is incurred separately for downloading applications andusing special features of them. For your information, KEW Smart for KEW
3552BT is provided on-line only.
Features of KEW Smart for KEW 3552BT:● Remote monitoring/ checking● Data save/ recall function● Insulation status indicator
Buzzer sounds when the measured value is below the reference value.
Please see 8-5. Insulation status indicator.
● Map display (available on Android devices only)
Measured locations can be checked on the Google Maps if the saved
data includes GPS location info.
● Comment editing
Measured result can be saved with comments.
The latest information about KEW Smart for KEW 3552BT can be checkedwith the site on Google Play Store or App Store.

̶ 42 ̶

16. Battery replacement
Replace batteries with new ones when the battery indicator shows; battery level is almost empty.
# DANGER● Do not open the battery compartment cover if the instrument is wet.
● Never attempt to replace batteries during a measurement. When opening
the battery compartment cover, ensure that the instrument is powered off
and no test leads are connected to, in order to avoid getting electricalshock.
● The battery compartment cover must be closed and screwed before
making measurement.
# CAUTION● Do not mix new and old batteries nor different types of batteries.
● Install batteries in correct polarity as marked inside.

Fig. 16-1(1) Power off the instrument and disconnect the test leads.
(2) Loosen one screw fixing the battery compartment cover, and remove thecover.
(3) Replace all four batteries with new ones at the same time with observing
correct polarity. Use of size AA alkaline battery (LR6) x 4 is recommended.
(4) Install the battery compartment cover and tighten one cover-fixing screw.

̶ 43 ̶

17. Shoulder strap belt attachment
Strap belt is supplied with this instrument to suspend from the neck to allow
both hands to be used freely for easy and safe operation.

Fig. 17-1

18. Storing in carrying caseStore the instrument and test leads as the following figure shows.
Test leads compartment

Partition
Flat test bar

Unit compartment

Fig. 18-1# CAUTION● Always power off the instrument before storing it in the carrying case.

̶ 44 ̶DISTRIBUTOR

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

12-23

92-2339B