Kyoritsu Electrical Instruments KEW6516BT, KEW6516 User manual

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11. RCD tests ................................................................................................................48

11.1 Principles of RCD measurement ..................................................................... 48

11.2 Principles of Uc measurement ......................................................................... 50

11.3 Measurement method for RCD ........................................................................ 50

11.4 Auto test ........................................................................................................... 53

11.5 VAR (variable current value) function ..............................................................53

11.6 EV RCD ........................................................................................................... 54

12. Earth tests ............................................................................................................... 54

12.1 Principles of earth measurement ..................................................................... 54

12.2 Earth resistance measurement........................................................................ 54

12.3 Measurement method for earth ....................................................................... 55

13. Phase rotation tests ................................................................................................. 57

14. Volts ......................................................................................................................... 58

15. Touch pad ................................................................................................................ 58

16. Memory function ...................................................................................................... 59

16.1 How to save the data ....................................................................................... 59

16.2 Recall the saved data ...................................................................................... 60

16.3 Delete the saved data...................................................................................... 61

17. Transfer the stored data to PC ................................................................................62

18. Bluetooth communication (KEW 6516BT only) ....................................................... 63

18.1 Bluetooth communication ................................................................................ 63

18.2 KEW Smart * ................................................................................................... 64

19. Auto-power-off ......................................................................................................... 64

20. Battery and fuse replacement.................................................................................. 65

20.1 Battery replacement ........................................................................................ 66

20.2 Fuse replacement ............................................................................................ 65

21. Servicing .................................................................................................................. 66

22. Case and strap assembly ........................................................................................ 67

The KEW 6516/6516BT incorporates Anti Trip Technology (ATT) which electronically
bypasses RCDs when performing loop impedance tests. This saves time and money by
not having to take the RCD out of the circuit during testing and is a safer procedure to
follow. With the ATT function enabled, a test of 15mA or less is applied between line &
earth. It enables loop impedance measurements without tripping RCDs rated at 30mA
and above.
ATT supports measurements using three wires: Line, Earth, and Neutral and also two
wires: Line and Earth.
Please read this instruction manual carefully before using this instrument.

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1. Safe testing

This instrument has been designed, manufactured and tested according to IEC 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 to maintain 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 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 # 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.

# DANGER

● Do not apply voltages above 600V, including voltage to earth, across the terminals

of this instrument.

● KEW 6516/ 6516BT are rated to CAT IV 300V/ CAT III 600V. Do not make

measurements under the circumstances exceeding the designed measurement
categories.

● Do not attempt to make measurements 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 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 or conditions;

otherwise, safety functions equipped with the instrument don't work, and instrument
damage or serious personal injury may be caused.

● Verify proper operation on a known source before use or take actions as a result of

the indication of the instrument.

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# WARNING

● Do not use the instrument or test leads if any abnormal conditions, such as broken

cover or exposed metal parts are noted.

● First, firmly connect the test leads to the instrument, and then press the test switch.

● 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.

● Before opening the battery compartment cover for battery or fuse replacement,

ensure that no test leads are connected to the instrument and the instrument is off.

● Never turn the rotary switch while the test leads are connected to the equipment

under test.

# CAUTION

● Always make sure to set the rotary 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 into storage.

● Keep your hand and fingers behind the protective finger guard during a

measurement.

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2. Instrument layout

(7)

(2)

(8)

(5)

(1)

(3)

(4)

Fig.2-1

Item Description

(1) Test switch Starts measurements. (Press and rotate for lock down

feature.)

(2) Touch pad Checks the electrical potential at the PE terminal

(3) Power switch A long press turns on/ off the instrument.

(A short press works as an ESC switch to return to the
previous screen.)

(4) Function switch Function setting (F1 ~ F4)

(6)

(5) Display (LCD) Color LCD

(6) Rotary switch Selects measurement functions.

(7) MEM switch Saves measured value.

(Press 1 sec. to recall the saved data.)

(8) ENTER switch Confirms changes or selections.

(A long press of 1 sec. shows "HELP" menu.)

3

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Input Terminal

(1)

(2)

(3)

Function Terminal

(4)

Fig.2-2

Terminals for :
INSULATION,
CONTINUITY

(1)

LOOP,
RCD,
VOLTS

Terminal for

(2)

PHASE ROTATION

(3) Terminal for EARTH

(4) Optical adapter Communication port for Model 8212USB

L : Line

PE : Protective Earth

N : Neutral (for LOOP, RCD)

L1 : Line1

L2 : Line2

L3 : Line3

H(C) : Terminal for auxiliary earth spike (current)

E : Terminal for the earth under test

S(P) : Terminal for auxiliary earth spike (potential)

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3. Accessories

●Test leads
(1) Mains Test Lead (Model 7218A)

Red (Line)

Green (Protective Earth)

Blue (Neutral)

Fig. 3-1 shows Model 7218A with European SHUKO plug: plug shape varies depending
on the country or region. Any of the following test leads is selected and packed
according to destination.

●Model 7222A(AU) for Australian plug

●Model 7187A (UK) for British plug

●Model 7221A (SA) for South African plug

(2) Remote Test Lead (Model 7281)

*1 Protective Finger Guard

Attach the supplied detachable

Insulation cap

Metal tip

Fig.3-2

(3) Distribution Board test lead (Model 7246)

cap as necessary.

For CAT III 600V (w/ cap)
For CAT II 1000V (w/o cap)

Red (Line or L1)

Fig.3-1

Green (Protective Earth or L2)

Blue (Neutral or L3)

*1 Protective Finger Guard

Fig.3-3

* 1 Protective finger guard is a part providing protection against electrical shock and

ensuring the minimum required clearance and creepage distances.

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(4) Earth Tests Lead (Model 7228A) and Auxiliary Earth Spikes

Red H(C) 20m

Yellow S(P)10m

Fig.3-5

Green E 5m

Fig.3-4

・Other accessories
(1) Test Lead Carry pouch Model 9084･･･x1
(2) Carrying Bag Model 9142･･･x1
(3) Instruction Manual･･･x1
(4) Shoulder Strap (with buckle) Model 9151･･･x1
(5) Shoulder Pad Model 9199･･･x1
(6) Battery･･･x8
(7) Spare Fuse F 0.5A 600V (Φ6.3 x 32mm)･･･ x1 (SIBA 7009463.0,5)
  *Stored in the battery compartment.
(8) Model 8212USB with PC Software KEW Report.
(Standard accessory for KEW 6516, optional for KEW 6516BT)

Fig.3-6

Model 8041 Auxiliary Earth Spikes x 2

・Optional item
(1) Extension prod Model 8017A
* Attached and used with Model 7281.

Fig.3-7

Long type and helpful to access
the distant measurement spot

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4. Features

The KEW 6516/ KEW 6516BT Multi-Function tester has eight test functions in one
instrument.

1 Continuity test
2 Insulation resistance test
3 Loop impedance test (High current measurement, No trip (ATT) measurement)
4 Prospective short circuit current test (On Loop impedance function)
5 RCD test
6 Voltage test
7 Phase rotation test
8 Earth test

Continuity function has the following features:

Continuity Function has a fuse protection function to prevent

Fuse Protection

Continuity Null

15mA test Not only 200mA but also 15mA is available.

Continuity 2Ω Buzzer

Insulation function has the following features:

Auto-discharge

SPD(VARISTOR) test

a fuse blow at live working. With this function, a fuse rarely
blows while measuring continuity on live conductors.

Allows automatic subtraction of test lead resistance from
continuity measurements.

Buzzer sounds at 2Ω or less at Continuity function.
(Switchable on or off)

Electric charges stored in capacitive circuits are discharged
automatically after testing by releasing the test switch.
Breakdown voltage measurement for surge protective device
(varistor)

Loop impedance functions have the following features:

ATT test

LOOP 0.001Ω test

Enables loop impedance tests without tripping RCDs rated at
30mA or higher. (applicable to 3 or 2-wire measurements)

High resolution measurement, 0.001Ω, at a test current of
25A

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RCD testing functions have the following features:

RCD Type B test Capable of testing Type B RCDs of dc residual current.

VAR(variable test current)

RCD AUTO TEST

EV RCD EV charger RCD test

The following features are available on all testing functions.

Touch Pad

Memory Function

Bluetooth
(KEW 6516BT only)

Test current is variable on RCD range.
Auto-test in the following sequence: ×1/2(0°)→×1/2(180°)

→ ×1(0°)→×1(180°)→×5(0°) →×5(180°)

Gives an alert, when touching the Touch Pad, while the PE
terminal is connected to Line by mistake.

Save the measured data in the internal memory.
The data can be edited on a PC by using Communication
Adapter Model 8212USB and PC Software "KEW Report".

Remote monitoring and saving data on a Bluetooth tablet
device.

8

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5. Specification

5.1 Measurement specification

VOLTS

Range 300.0/600V (Auto-ranging)

Display range

Measuring range

(Guaranteed accuracy

range)

Accuracy

* True-RMS detection. Add ±1%rdg to the declared accuracy for sine wave other than

CF<2.5. (850Vpeak or less)

PHASE ROTATION

Measuring range 48 – 600V 45 - 65Hz

Criteria of judgement

EARTH

Range 20.00/ 200.0/ 2000Ω (auto-ranging)

Display range

Measuring range

(Guaranteed

accuracy range)

Accuracy

Output current

Frequency: 40.0 – 70.0Hz (displayed at 2V or higher)

Correct sequence: Clockwise symbol and "1, 2, 3" are
displayed.
Reversed sequence: Counter-clockwise symbol and "3, 2, 1"
are displayed.

Precise measurement Simplified measurement

20Ω range; ±2%rdg±0.08Ω

The other ranges: ±2%rdg±3dgt

(Auxiliary earth resistance: 100Ω)

Voltage: 2.0 – 314.9V, 240 – 629V

Voltage: 2 – 600V

Frequency: 45 – 65Hz

Voltage: ±2%rdg±4dgt

Frequency: ±0.5%rdg±2dgt

0.00 – 20.99Ω

16.00 – 209.9Ω

160.0 – 2099Ω

0 – 2000Ω

±2%rdg±0.08Ω

The other ranges:

±2%rdg±3dgt

20Ω range: approx. 3mA

200Ω range: approx. 1.7mA

2000Ω range: approx. 0.7mA

Frequency: 825Hz

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CONTINUITY

Range 20.00/200.0/2000Ω (auto-ranging)

0.00 - 20.99Ω

Display range

Measuring range

(Guaranteed accuracy range)

Accuracy (NULL enabled) ±2.0%rdg±8dgt

Open-circuit voltage (DC) 7 – 14V

Test current

● Enabled if pre-set NULL value is 9Ω or less.

● 2Ω Buzzer: Buzzer sounds when measured resistance is 2Ω or less.

INSULATION
(1) INSULATION RESISTANCE

Rated

measurement

voltage

Range

Display range

Measuring range

(Guaranteed

accuracy range)

Accuracy

Rated

measurement

current

● Open-circuit voltage: 100 – 120% of rated measurement voltage

● Short-circuit current: within 1.5mA

● The tester outputs negative voltage from LINE terminal and positive voltage from

EARTH terminal.

● Max. capacitive load: 1μF: capacitive load dischargeable within 10 sec after test

(IEC 61010-2-034)

● Discontinuous beeps sound during a measurement on 1000V range.

100V 250V 500V 1000V

2.000/20.00/200.0MΩ

auto-ranging

0.000 - 2.099MΩ

1.60 - 20.99MΩ

16.0 - 209.9MΩ

0 - 200MΩ 0 - 1000MΩ 0 - 2000MΩ

2.000MΩ range: ±2%rdg±6dgt

20.00MΩ range: ±2%rdg±6dgt
200MΩ range: ±5%rdg±6dgt

1.0 - 1.2mA

at 100kΩ

1.0 - 1.2mA

200mA test: 200mA or more (2Ω or less)

15mA test: 15mA±3mA (short-circuit)

at 250kΩ

16.0 - 209.9Ω
160 - 2099Ω

0 – 2000Ω

20.00/200.0/1000MΩ

auto-ranging

0.00 - 20.99MΩ

16.0 - 209.9MΩ
160 - 1049MΩ

20.00MΩ range: ±(2%rdg+6dgt)

200.0MΩ range: ±(2%rdg+6dgt)

1000MΩ range:

±(5%rdg+6dgt)

1.0 - 1.2mA

at 500kΩ

20.00/200.0/2000MΩ

auto-ranging

0.00 - 20.99MΩ

16.0 - 209.9MΩ
160 - 2099MΩ

2000MΩ range:

±(5%rdg+6dgt)

1.0 - 1.2mA

at 1MΩ

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(2) SPD test

Range 1000V

Display range 1049V

Measuring range 0 - 1049V

Accuracy ±5%rdg±5dgt

Voltage increase rate 100V / sec.

Voltage increase step Increases by 1V.

Threshold value for current detection 1mA

LOOP ATT

Function 3-Wire L-PE 2-Wire L-PE

Mains input

voltage range

Range

Display range

Measuring range

(Guaranteed

accuracy range)

Accuracy

Test current

@230V

* If a reading is unstable, one upper range digit might be used instead of the display

range to be used.

LOOP 20.00/200.0/2000Ω (auto-ranging)

PFC/PSC 2000A/20kA 2000A/20kA (PFC only)

LOOP

PFC/PSC

LOOP 0 – 2000Ω 0 – 2000Ω

LOOP

PFC/PSC

100 – 260V 50/60Hz

(L-N < 20Ω)

0.00 – 20.99Ω

21.0 – 209.9Ω
210 – 2099Ω

0 – 2099A

2.10 – 20.99kA

230V+10%-15%:

±(3%rdg+6dgt)

Other than above voltages:

±(3%rdg+8dgt)

Depending on the accuracies of voltage and LOOP

measurements

L-N:6A/60ms

N-PE:10mA (5.3Hz)

48 – 260V 50/60Hz

0.00 –20.99Ω

21.0 –209.9Ω
210 –2099Ω

0 – 2099A

2.10 – 20.99kA
(PFC only)

230V+10%-15%:

±(3%rdg+10dgt)

Other than above voltages:

±(3%rdg+15dgt)

L-PE: 15mA

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LOOP HIGH

Function L-PE0.01ΩRes L-PE0.001ΩRes L-N/L-L

Mains input

voltage range

LOOP

Range

Display

range

Measuring

range

(Guaranteed

accuracy

range)

Accuracy

Test current

* If a reading is unstable, one upper range digit might be used instead of the display

range to be used.

PFC/PSC

LOOP

PFC/PSC

LOOP 0 – 2000Ω 0 – 2Ω 0 – 20Ω

LOOP

PFC/PSC

@230V

48 - 260V

50/60Hz

20.00/200.0/2000Ω

2000A/20kA

(PFC only)

0.00 - 20.99Ω

21.0 - 209.9Ω
210 –2099Ω

0 - 2099A

2.10 - 20.99kA
(PFC only)

230V+10%-15%:

±(3%rdg+4dgt)

100V or less:

±(5%rdg+15dgt)

Other than above

voltages:

±(3%rdg+8dgt)

Depending on the accuracies of voltage and LOOP

20Ω: 6A/20ms

200Ω: 0.5A/20ms

2000Ω:

15mA/500ms

100 - 260V

50/60Hz

2.000Ω 20.00Ω

2000A/50kA

(PFC only)

0.000 - 2.099Ω 0.00-20.99Ω

0 - 2099A

2.10 - 52.49kA
(PFC only)

230V+10%-15%:
±(3%rdg+25mΩ)

Other than above

voltages:

±(5%rdg+35mΩ)

measurements

25A/20ms 6A/20ms

48 - 500V

50/60Hz

2000A/20kA

(PSC only)

0 - 2099A

2.10 - 20.99kA
(PSC only)

230V+10%-15%:

±(3%rdg+4dgt)

100V or less:

±(5%rdg+15dgt)

Other than above

voltages:

±(3%rdg+8dgt)

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RCD
(1) Mains input voltage range: 100V – 260V 50/ 60Hz
For Type AC and A RCDs rated at 100mA or higher: 190 – 260V
(2) Accuracy

Rated residual operating

×1/2

×1

×5

RCD
Type

G 10/30/100/300/500/1000

AC

S 10/30/100/300/500

G 10/30/100/300/500

A/F

S 10/30/100/300/500

G 10/30/100/300

B

S 10/30/100/300

G 10/30/100/300/500/1000

AC

S 10/30/100/300/500

G 10/30/100/300/500

A/F

S 10/30/100/300/500

G 10/30/100/300

B

S 10/30/100/300

EV 6 I⊿n 0% to +10% 10.5s

G 10/30/100

AC

S 10/30/100

G 10/30/100

A/F

S 10/30/100

G 10/30

B

S 10/30

G 10/30/100/300/500

AC

S 10/30/100/300/500

G 10/30/100/300/500

A/F

S 10/30/100/300/500

G 10/30/100/300

B

S 10/30/100/300

EV

current (mA)

(I⊿n)

6 I⊿n -10% to +10%

Current value

10mA: I⊿n×2

Other currents:

I⊿n×5×1.4 0% to +10%

10mA:I⊿n×2

Other currents:

Mode

Ramp

20% to

110%

(EV 30%

to 100%)

・AUTO-TEST：X1/2(0°)→X1/2(180°)→X1(0°)→X1(180°)→X5(0°)→X5(180°)
 The test of "X5" will be skipped when a current is 100mA or higher.
 At the auto-test for Type EV, additional 6 mA DC test is performed.

Current waveform of KEW 6516/6516BT

・Type AC: Test current is sine wave.
・Type A and F: Test current is half sine wave.
・Type B and EV: Direct current

Test current Duration

(mA) rms

I⊿n×1/2

I⊿n×0.35 -10% to 0%

I⊿n×1/2 -10% to 0%

I⊿n

I⊿n×1.4

I⊿n×2 0% to +10%

I⊿n×5

I⊿n×2×5 0% to +10%

I⊿n -4% to +4%

I⊿n×1.4

I⊿n×2 -10% to +10%

Accuracy @230V

-8% to-2%

VAR:-10% to 0%

+2% to +8%

VAR:0% to +10%

0% to +10%

+2% to +8%

VAR:0% to +10%

-10% to +10%

Measuring

time

2000ms

G:550ms

S:1000ms

410ms

by 10%
G: 300ms
S: 500ms

by 2%
150ms

by 2%

500ms

(10s is kept

only at 100%)

Accuracy

Trip Time

±(1%+2ms)

Measuring

time

±3% of FS

Measuring

time

±3% of FS

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(3) Uc(RCD)

Mains input voltage range 100-260V

Range 100V

Display range 0.0 - 104.9V

Measuring range

(Guaranteed accuracy range)

Accuracy +5% to+15%rdg±8dgt @230V

Test current 50 % or less of IΔn

Possible number of tests with fresh batteries.

CONTINUITY : Approx. 2000 times min. at load 1Ω
INSULATION RESISTANCE : Approx. 1500 times min. at load 1MΩ (1000V)

LOOP : Approx. 3000 times min. (ATT L-PE 3W)

RCD : Approx. 3500 times min. (G-AC X1 30mA)
EARTH : Approx. 3000 times min. at load 10Ω

VOLTS/PHASE ROTATION : Approx. 40h

5.2 General specification

Specifications are based on the following conditions except
where otherwise stated:-

1. Ambient temperature: 23±5°C:

Reference conditions

Instrument dimensions 235 X 136 X 114mm

Instrument weight 1350g (including batteries)

Battery type Size AA Alkaline battery (LR6) x 8

Operating temperature
and humidity

Storage temperature
and humidity

Display Color Dot Matrix LCD 320(W) X 240(H) pixels.

Overload protection

2. Relative humidity: 45% to 75%

3. Nominal voltage of distribution system (Un) :

4. Altitude: Less than 2000m

-10 to +50°C, relative humidity 80% or less, no condensation

-20 to +60°C, relative humidity 75% or less, no condensation

The continuity test circuit is protected by a 0.5A/600V fast
acting (HRC) ceramic fuse mounted in the battery
compartment, where a spare fuse is also stored.
The insulation resistance test circuit is protected by a
resistor against 1000V AC for 10 seconds.

0 - 100V

230V/400V, 50Hz/60Hz

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5.3 Applied standards

Instrument operating
Standard

Safety standard

Protection degree IEC 60529 IP40

EMC EN 61326-2-2

This manual and product may use the following symbols adopted from International
Safety Standards;

CAT II

CAT III

CAT IV

Measurement category "CAT II" applies to;
Electrical circuits of equipment connected to an AC electrical outlet by a
power cord.

Measurement category "CAT III" applies to;
Primary electrical circuits of the equipment connected directly to the
distribution panel, and feeders from the distribution panel to outlets.

Measurement category "CAT IV" applies to;
The circuit from the service drop to the service entrance, and to the power
meter and primary overcurrent protection device (distribution panel).

Equipment protected throughout by DOUBLE INSULATION or



REINFORCED INSULATION;

Caution (refer to accompanying documents)

#

Caution, risk of electric shock



Protection against wrong connection is up to 600V

Earth Ground



Complies with WEEE Directive (2002/ 96/ EC) marking requirements. (valid
in each EU country)

IEC61557-1,2,3,4,5,6,7,10

IEC 61010-1, -2-030, -2-034
CATIII (600V) CATIV (300V) -Instrument
IEC 61010-031
Model 7218A…CAT II 250V
Model 7246 …CATIII 600V/ CATIV300V
Model 7228A…CATIII 300V
Model 7281 …CATIII 600V/ CATIV300V (w/ cap)
…CAT II 1000V (w/o cap)
…CAT II 1000V (w/ 8017A)
( Attach the supplied protective cap to use this test leads in CAT

III or higher environments.)

* When test leads, sometimes with metal tips, are connected

and used with the instrument, the measurement category and
voltage rating of the lowest rated item is applied.

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.

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O (None, other) : Circuits which are not directly connected to the mains power supply.
CAT II : Electrical circuits of equipment connected to an AC electrical outlet

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, and to the

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

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

5.4 Operating uncertainty

Continuity (EN61557-4)

Operating range compliant with EN61557-4

operating uncertainty

Maximum percentage operating

uncertainty

0.20 to 2000Ω ±30%

The influencing variations used for calculating the operating error are denoted as follows;
Temperature: 0℃ and 35℃
Supply voltage: 8V to 13.8V

Insulation Resistance (EN61557-2)

Volt

Operating range compliant with

EN61557-2 operating uncertainty

Maximum percentage

operating uncertainty

100V 0.100 to 200.0MΩ
250V 0.250 to 200.0MΩ
500V 0.50 to 1000MΩ

±30%

1000V 1.00 to 2000MΩ

The influencing variations used for calculating the operating error are denoted as
follows;
Temperature: 0℃ and 35℃
Supply voltage: 8V to 13.8V

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Loop Impedance (EN61557-3)

Function

Operating range compliant

with EN61557-3 operating

uncertainty

Maximum percentage

operating uncertainty

L-PE 0.01Ω Res 0.40 to 2000Ω

HIGH

ATT

L-PE 0.001Ω Res 0.400 to 1.999Ω

L-N/L-L 0.40 to 20.00Ω

2Wire 1.00 to 20.00Ω
3Wire 0.40 to 2000Ω

±30%

The influencing variations used for calculating the operating error are denoted as follows;
Temperature: 0℃ and 35℃
Phase angle: At a phase angle 0° to 30°
System frequency: 49.5Hz to 50.5Hz
System voltage: 230V+10%-15%
Supply voltage: 8V to 13.8V
Harmonics: 5% of 3
6% of 5
5% of 7

rd

harmonic at 0°phase angle

th

harmonic at 180°phase angle

th

harmonic at 0°phase angle

DC quantity: 0.5% of the nominal voltage

RCD (EN61557-6)

Function Operating uncertainty of trip current

X1/2 -10% to 0%

X1, X5 0% to +10%

Ramp -10% to +10%

The influencing variations used for calculating the operating error are denoted as follows.

・Temperature : 0℃ and 35℃
・Earth electrode Resistance (shall not exceed below) :

IΔn Type AC Type A/F Type B Type EV

6mA - - - 400Ω
10mA 400Ω 200Ω 40Ω ­30mA 100Ω 40Ω 10Ω -

100mA 40Ω 20Ω 10Ω ­300mA 40Ω 20Ω 2Ω ­500mA 40Ω 20Ω - -

1000mA 20Ω - - -

・System voltage: 230V+10%-15%
・Supply voltage : 8V to 13.8V

Earth Resistance (EN61557-5)

Operating range compliant with EN61557-5

operating uncertainty

Maximum percentage operating

uncertainty

5.00 to 1999Ω ±30%

The influencing variations used for calculating the operating error are denoted as follows;

・Temperature : 0℃ and 35℃
・Series interference voltage : 16·2/3Hz, 50Hz, 60Hz, DC:10V

400Hz: 3V

Resistance of the probes and auxiliary earth electrode resistance: 100 x RA, 50kΩ or less

・
・Supply voltage : 8V to 13.8V

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5.5 Symbols and marks displayed on the LCD

Battery level indicator

Temperature monitor for internal resistance, available at
Loop, RCD function. Further measurements are suspended
until the "

Measurements in progress

" symbol disappears.

Live Circuit

PE Hi V

L-N >10Ω

N - PE Hi V

Uc > UL

no

R

H Hi, Rs Hi

No 3-phase system

N-PE Hi Ω

Live circuit warning (Continuity / Insulation / Earth Function)

Caution: Presence of 100V or more at PE terminal, appears
when touching the Touch Pad

Alert: Presence of 10Ω or more between Line - Neutral at
ATT measurement

Caution: Presence of noise in the circuit under test during
ATT measurement.

Caution: Presence of high voltage between NEUTRAL ­EARTH during LOOP ATT measurement.

Caution: Uc at RCD test is exceeding the preset UL value
(25 or 50V).

Error message: When on the RCD function, RCD tripped
before measuring RCD trip time. Selected IΔn value may
not be correct.
When on the LOOP, PSC/PFC function, supply may have
been interrupted.

Wiring check for LOOP, RCD function

Judged result of each test

: Satisfied the reference value, : Unsatisfied.
: Unjudgeable: Measured result exceeds the measuring

range, and the upper limit of the measuring range is

smaller than the reference value.
Appears when setting PAT for Continuity/Insulation function
and limit value for LOOP measurement.

Appears when a Probe resistance of H terminal (R
of S terminal (R
measurable range.

Appears to indicate wrong connection at Phase Rotation
check.

For RCD Type B and EV, appears to indicate too high
resistance exists between N-PE to apply test current.

S) at Earth measurement is exceeded the

H) or

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6. Setup mode

Enter in the SETUP mode to make settings of the instrument. The following settings are
changeable.

(1) LANGUAGE .............. Language selection

(2) TIME ......................... Clock adjustment

(3) LCD Contrast ............ LCD contrast adjustment LCD

(4) LCD Backlight ........... LCD backlight brightness adjustment LCD

(5) UL value .................... Selects a UL value for RCD function

(6) Touch Pad ................. Enables / disables Touch Pad function

Setting method:
(1) Press F4 "SETUP" while the start-up screen is displayed (approx. 2 sec.) after

turning on the instrument.
(2) SETUP screen appears. (See Fig. 6-2.)
The screen also can be referenced in the HELP menu: press F4 while the LCD is

showing wiring configuration diagram.

Selected item
is highlighted
in white.

Fig.6-1 Fig.6-2

(3) Press ▲(F1) or ▼(F2) switch for item selection and confirm the selection with

ENTER switch.
(4) Press ▲(F1) or ▼(F2) switch and change settings. The changeable settings are as

follows.

Item Setting

LANGUAGE

TIME Adjusts day, month, year, minute and hour.

LCD Contrast Up or Down

LCD Backlight Up or Down

UL value 25V or 50V

Touch Pad ON or OFF

(5) Press ENTER when settings are done. Then the screen returns to the SETUP

MENU screen as Fig. 6-2. Press ESC to cancel the changes.
(6) Pressing ESC on SETUP MENU screen (Fig. 6-2) gets the instrument in stand-by

mode.

Note: Selectable language may not be the same as listed above depending on the

countries and regions.

Press F4.

ENGLISH, FRENCH, POLISH, ITALIAN, SPANISH,

TURKISH, DUTCH, CZECH

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7. Getting started

7.1 Attaching metal tip/ adapter for test leads

The following metal tips and adapters are user-changeable depending on measurement
purposes.
(1) For Model 7281
The following metal tips are available.

1. Standard metal tip Installed at a shipment supplied with a detachable

insulation cap.

2. Model 8017A Long type and helpful to access the distant point.

[How to replace the parts]
Turn the tip of Model 7281 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.

Fig.7-1

(2) For Model 7246
Either of the following adapters can be attached to.

1. Alligator clip

2. Test probe

Alligator clip

Banana plugs, both ends

Test probe

# DANGER

To avoid getting electrical shocks, disconnect the test leads from the instrument before
replacing the metal tip or adapter.

Fig.7-2

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7.2 Battery voltage check

(1) Please refer to "20. Battery and fuse replacement" in this manual and insert

batteries in the instrument.
(2) Press Power switch to turn on the instrument.
(3) Check the battery status indicator displayed at the upper right corner of the LCD.
"
"

"
In such a condition, accuracy of the measured result isn't guaranteed.

● Battery status indicator might change from " " to " " during a measurement

depending on measured objects; for example, resistance of the object is low.

7.3 Clock adjustment

KEW 6516/ 6516BT has clock function. Time is
displayed in the upper right corner of the LCD.
Time display format: Day/ Month/ Year / Hour: Min
Enter the SETUP mode to adjust clock. Press ENTER
when clock adjustment is done.
See "6. Setup mode" for further detail of "SETUP"
mode.

(1) On the clock adjustment screen (Fig. 7-4), select

the parameter (day/ month/ year/ hour/ min) to be

adjusted with ◀(F3) or ▶(F4) switch.
(2) Use ▲(F1) or ▼(F2) switch to alter the value of the

selected parameter and press ENTER to confirm.

(Pressing ESC switch during the adjustment can

one step back.)

" : Normal. Battery voltage is enough.
" : Low battery voltage: For continuous measurement, please refer to

"20. Battery and fuse replacement" and replace the batteries with
new ones.

": Battery voltage is below the lower limit of the operating voltage.

Replace batteries with new ones immediately.

Clock

Fig.7-3

Fig.7-4 Clock adjustment
Note:
Clock setting will be cleared if no batteries were inserted in the instrument 10 min. or
longer. When battery replacement is required, be careful not to exceed this period. If the
clock setting is cleared and restored to the default, please do the setting again.

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7.4 Help function

With this function, correct connection for each test can be displayed on the LCD.

To check a connection diagram;
(1) Make settings of measurement parameters on each function, hold down HELP

(ENTER) switch 1 sec.

(2) Then the LCD shows a connection diagram.

Fig.7-5 Connection diagram example

(3) When several connections are available, press F1 switch to toggle the diagrams.
(4) Press ESC to close the currently displayed connection diagram screen.

● The SETUP screen for making each setting will appear by pressing F4 (SETUP)

switch while the LCD is showing a connection diagram.

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8. Continuity (resistance) tests

# DANGER

Do not apply voltage to the continuity function. Always check the circuit or equipment
under test is surely de-energized before starting a measurement.

8.1 Test procedure

The object of continuity testing is to measure only the resistance of the parts of the
wiring system under test. This measurement should not include the resistance of any
test leads used. The resistance of the test leads needs to be subtracted from any
continuity measurement. The KEW 6516/ 6516BT is provided with a continuity null
feature which allows automatic compensation for any test lead resistance.

You should only use the test leads supplied with the instrument.

LCD display and function switches

Switches on / off NULL

F1

function
Switches on / off 2Ω

F2

Measured value

Fig.8-1

Proceed as follows:
(1) Select the continuity test by turning the rotary switch.
(2) Insert the test leads to the L and PE terminals on KEW 6516/ 6516BT respectively

as shown in Fig.8-2.

buzzer

Pat mode setting

F3

(OFF, 0.1Ω, 0.3Ω,1Ω)

Test current setting

F4

200mA or 15mA

L terminal
Red cord of Model 7246, or
Model 7281 Remote Test Lead

PE terminal

Red

(3) Connect the ends of the test leads firmly together (see Fig. 8-3) and press and

lock down the test switch. The value of the lead resistance will be displayed. The
"

" symbol is displayed to the left of the reading during a measurement.

Green

Fig.8-2

Green cord of Model 7246

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Fig.8-3

(4) Press the F1(NULL) switch, this will null out the lead resistance and the indicated

reading should go to zero.

(5) Release the test switch. Press the test switch and ensure the display reads zero

before proceeding. While using the Continuity null function, "NULL ON" is displayed
on the LCD as indicated in Fig.8-3.

●The null value will be stored even if the instrument is powered off.

● This memorized null value can be cancelled by disconnecting the test leads and

pressing F1(NULL) switch with the test switch pressed or locked.

●When this is cancelled you will know because NULL OFF is displayed on the LCD.

# CAUTION

Before taking any measurements always check the leads have been zeroed.

(6) Connect the test leads to the circuit whose resistance is required (see Fig. 8-4 for a

typical connection arrangement), having first made sure that the circuit is not live.

Note that "Live Circuit" warning will be displayed on the LCD if the circuit is live - but

check first anyway!

Fig.8-4 Example of continuity test for main equipotential bonding.

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(7) Press the test switch and read the circuit resistance from the display. The reading

will have the test lead resistance already subtracted if the Continuity null function
has been used.

Note: If the reading is greater than 2099Ω the over range symbol '>' will remain

displayed.

# WARNING

The results of measurements can be adversely affected by impedances of additional
operating circuits connected in parallel or by transient currents.

Fig.8-5

● 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 be damaged if the open
measuring terminals are connected to a live wire.

8.2 2Ω Buzzer (

Use F2 switch to enable (
when measured resistance is 2Ω or less while this function is enabled. The buzzer does
not sound if it is disabled.

8.3 Switching test currents

KEW 6516/ 6516BT can perform continuity test at 200mA and also 15mA. Press F4
switch to switch the current between 200mA and 15mA.

8.4 Pat function

PAT function is available to do continuity test for portable appliances,
(1) Press F3 to select the criteria value for PAT test. (See the table below.)

Item Criteria of judgement
PAT O FF ­PAT 0 .1Ω

PAT 0 .3Ω

PAT 1 Ω

) function

) / disable ( ) the 2Ω Buzzer. The buzzer sounds

"✓" : 0.1Ω or less
"X" : over 0.1Ω
"✓": 0.3Ω or less
"X" : over 0.3Ω
"✓" : 0.3Ω or less
"X" : over 0.3Ω

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(2) Make connections as Fig. 8-6 shows to check continuity.
At a PAT testing, "✓" or "X" will be displayed next to the reading to show PASS/

FAIL.

N

L

E

Fig.8-6

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9. Insulation tests

This instrument is used to measure insulation resistance of electric appliance or circuit
to inspect the insulation performance. Check the voltage rating of the object to be tested
before making measurement and select the voltage applied to.

● Depending on the object to be measured, displayed insulation resistance value may

not stabilize.

● The instrument may give bleep during an insulation resistance measurement;

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 when measuring
insulation resistance against ground or when a part of the object under test is
earthed. Such connection is known to be more suitable for insulation testing since
insulation resistance values measured with the positive side connected to earth are
typically less than those taken through the 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 high voltage 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 the instrument.

# 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.

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9.1 Measurement method

Red

On the INSULATION function, breakdown voltage of Surge protect device (SPD,
VARISTOR) can be tested in addition to normal insulation resistance.

LCD display and function switches

F1 Test mode selection

Insulation or SPD

F2 Voltage setting

Measured value

1-min value

DAR/ PI values

Duration

(1) Select INSULATION function with the rotary switch.
(2) Press F1 switch and select the test you wish to do: "INSULATION" or SPD:
"SPD (VARISTOR)".
(3) Press F2 switch and select the desired voltage range.
(When selecting SPD test, the range is fixed to 1000V.)
(4) Insert the test leads to the L and PE terminals on KEW 6516/ 6516BT respectively

as shown in Fig. 9-2.

L terminal
Red cord of Model 7246, or
Model 7281 Remote Test Lead

PE terminal

Green

(5) Attach the test leads to the circuit or the appliance under test (See Fig. 9-3, Fig. 9-4,

and Fig. 9-5).

Fig.9-2

Green cord of Model 7246

(100V, 250V, 500V, 1000V)

F3 Pat mode setting

(OFF, PAT CL1, PAT CL2)

Output voltage

Fig.9-1

Fig. 9-3 Example of Insulation resistance test on 4 wire-3 phase system

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Fig.9-4

Fig. 9-5 SPD(VARISTOR) test connection

(6) If the "Live Circuit" warning is displayed on the LCD and/or the buzzer sounds, do

not press the test switch but disconnect the instrument from the circuit. Make the
circuit dead before proceeding.

(7) Press the test switch, the display will show the insulation resistance of the circuit or

the appliance to which the instrument is connected. At an SPD(VARISTOR) test, the

LCD will show a breakdown voltage.
(8) Auto discharge function
This function allows electric charges stored in the capacitor of the circuit under test to

be automatically discharged after measurement. Set the test switch or remote-control
switch to off with the test leads connected.

Discharge can be checked with the blinking "  " symbol and buzzer.

# 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.

● Measurement and elapsed time are displayed on the LCD during insulation

resistance measurement: up to 99 min. 59 sec. Note: The time counter stops and
freezes when it reaches to 99 min. 59 sec.; if the elapsed time exceeds 100 min.

● If the reading measured greater than 2099MΩ (209.9MΩ at 100V/ 250V, 1049MΩ at

500V) the over range reading '>' will be displayed.

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Fig.9-6

9.2 Continuous measurement (Insulation resistance measurement)

For continuous measurement, use the lock-down feature incorporated in the test switch.
Press and turn the test switch clockwise to lock the switch in operating position; to
unlock the switch, turn it counter-clockwise.

# DANGER

Be extremely careful not to touch the tips of test leads to avoid getting electrical shock
since high voltage is present continuously.

9.3 Voltage characteristics of measurement terminals

This instrument conforms to IEC61557. This standard defines that the rated
measurement current shall be at least 1mA, and the lower limit of the insulation
resistance maintaining the rated measurement voltage at measurement terminals. (See
the table below.) This value is calculated by dividing the rated voltage by rated current.
In case that the rated voltage is 500V, the lower limit of the insulation resistance is found
as follows.
Divide 500V by 1mA equals 0.5MΩ.
That is, insulation resistance of 0.5MΩ or more is required to provide the rated voltage
to the instrument.

Rated voltage 100V 250V 500V 1000V

Lower limit of the insulation resistance to
provide the rated current of 1mA

0.1MΩ 0.25MΩ 0.5MΩ 1MΩ

Fig.9-7

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9.4 DAR/ PI measurement, 1-min value display

DAR (Dielectric Absorption Ratio) and PI (Polarization Index) are automatically
measured during insulation resistance measurement.
When measurement time elapsed:

- 1 min: LCD shows DAR value.

- 10 min: LCD shows PI value.

The LCD shows the measured value, after 1 min has passed since the start of
measurement. Measured value is reviewable when 1 min elapses and also after the end
of measurement.

The table below shows the formula and the display range.

DAR = Resistance (1 min after a start of test) / Resistance (15 sec

Formula

Display range 0.00 to 9.99

*DAR and PI value to be displayed will be "no" if the resistance value applied in the
above formula is 0MΩ or out of display range. When DAR and PI values exceed the
display range, the LCD shows ">9.99".

9.5 Pat function

PAT function is available to do insulation test for portable appliances : this function is
available only on 250V and 500V range.
(1) Press F3 to select the criteria value for PAT test. (See the table below).

Item Criteria of judgement

PAT O FF -

PAT C L1

PAT C L2

(2) Make connections as Fig. 9-8 and 9-9 show to check insulation.
At a PAT testing, "✓" or "X" will be displayed next to the reading to show PASS/ FAIL.

after a start of test),
PI = Resistance (10 min after a start of test) / Resistance (1 min
after a start of test)

"✓": 1MΩ or more
"X": less than 1MΩ

"✓": 2MΩ or more
"X": less than 2MΩ

L

N

L

E

Fig.9-8 Fig.9-9

N

E

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9.6 SPD(Varistor) test

Breakdown
v

SPD test can measure a voltage which breakdowns surge protective device(varistor).
When the test gets started, the voltage KEW 6516/6516BT outputs automatically
increases from 0 V until the SPD breakdowns and the LCD shows the voltage value.
(If a 1 mA or higher current flow is detected, the instrument judges it is the breakdown
point.)

● Press the Test switch to start a measurement. Pressing F4 or ESC switch during a

measurement stops the measurement.

● The LCD shows SPD breakdown voltage (DCV) and also the assumed alternative

voltage (ACV).
The displayed ACV is determined by the following formula.
ACV = DCV/ 1.4

● If there's no SPD breakdown, the LCD shows ">1049V".

Breakdown
voltage (DCV)

oltage (ACV)

Fig. 9-10 SPD measurement screen

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10. LOOP/ PSC/PFC

10.1 Principles of measurement

(1) Principles of measurement of fault loop impedance and PFC

If an electrical installation is protected by over-current protective devices including circuit
breakers or fuses, the earth loop impedance should be measured.
In the event of a fault the earth fault loop impedance should be low enough (and the
prospective fault current high enough) to allow automatic disconnection of the electrical
supply by the circuit protection device within a prescribed time interval. Every circuit
must be tested to ensure that the earth fault loop impedance value does not exceed
that specified or appropriate for the over-current protective device installed in the circuit.
The KEW 6516/6516BT takes a current from the supply and measures the difference
between the unloaded and loaded supply voltages. From this difference it is possible to
calculate the loop resistance.

TT System

For a TT system the earth fault loop impedance is the sum of the following impedances;

●Impedance of the power transformer secondary winding.

● Impedance of the phase conductor resistance from the power transformer to the

location of the fault.

●The impedance of the protective conductor from the fault location to the earth system.

●Resistance of the local earth system (R).

●Resistance of the power transformer earth system (Ro).

The figure below shows (dotted line) the Fault loop impedance for TT systems.

Fig.10-1

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According to the International Standard IEC 60364, for TT systems the characteristics
of the protective device and the circuit resistance shall fulfill the following requirements:

Ra x Ia ≤ 50V

Where:
Ra is the sum of the resistances in Ω of the local earth system and the protective
conductor for the exposed conductive parts.
50 is the maximum safety touch voltage limit (it can be 25V in particular cases like
construction sites, agricultural premises, etc.).
Ia is the current causing the automatic disconnection of the protective device within the
maximum disconnecting times required by IEC 60364-41 that, for electrical installations
at 230 / 400V AC, are:

- 200 ms for final circuits up to 63A for socket, or up to 32A for fixed connected loads.

- 1 s for distribution circuits and circuits above mentioned over 63A and 32A.

The compliance with the above rules shall be verified by:

1) Measurement of the resistance Ra of the local earth system by Loop tester or Earth

tester.

2) Verification of the characteristics and/or the effectiveness of the RCD associated

protective device.

Generally, in TT systems, RCDs shall be used as protective device and in this case, Ia
is the rated residual operating current IΔn. For instance, in a TT system protected by a
RCD the max Ra values are:

Rated residual operating

current IΔn
RA (with touch voltage of 50V) 1667 500 167 100 50 (Ω)
RA (with touch voltage of 25V) 833 250 83 50 25 (Ω)

Shown below is a practical example of verification of the protection by RCD in a TT
system according to the international Standard IEC 60364.

30 100 300 500 1000 (mA)

Fig.10-2

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In this example, the max permissible value is 1667Ω (RCD =30mA and contact voltage
limit of 50V). The instrument reads 12.74Ω, thus the condition RA ≤ 50/Ia is respected.
However, considering that the RCD is essential for protection, it must be tested (Please
refer to RCD TESTS section).

TN System

For TN systems the earth fault loop impedance is the sum of the following impedances.

●Impedance of the power transformer secondary winding.

● Impedance of the phase conductor from the power transformer to the location of the

fault.

● Impedance of the protective conductor from the fault location to the power

transformer.

The figure below shows (dotted line) the Fault loop impedance for TN systems.

Fig.10-3

According to the International Standard IEC 60364, for TN system the characteristics of
the protective device and the circuit impedance shall fulfill the following requirement:

Zs x Ia ≤ Uo

Where:
Zs is the Fault loop impedance in ohm.
Uo is the nominal voltage between phase to earth (typically 230V AC for both single
phase and three phase circuits).
Ia is the current causing the automatic disconnection of the protective device within the
maximum disconnecting times required by IEC 60364-41 that, for installation at 230 /
400V AC, are:

- 400 ms for final circuits up to 63A for socket, or up to 32A for fixed connected loads.

- 5 s for distribution circuits and circuits above mentioned over 63A and 32A.

The compliance with the above rules shall be verified by:

1)Measurement of the fault loop impedance Zs by Loop tester.

2) Verification of the characteristics and/or the effectiveness of the associated protective
device. This verification shall be made:

- for circuit-breakers and fuses, by visual inspection (i.e. short time or instantaneous

tripping setting for circuit-breakers, current rating and type for fuses);

- for RCDs, by visual inspection and test using RCD testers recommending that the

disconnecting times mentioned above are met (Please see RCD TEST section).

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For instance in a TN system with nominal voltage at 230 / 400V AC and protected by fuse
or circuit breaker, knowing the curves characteristic of the gG fuses or MCBs (Miniature
Current Breakers according to IEC60898-1 and IEC60947-2) the max Zs values could be:

Protection

device

Disconnection

time

6A 5.00Ω 8.84Ω 7.67Ω 3.83Ω 7.67Ω 1.92Ω 3.83Ω 2.73Ω
10A 2.87Ω 5.00Ω 4.60Ω 2.30Ω 4.60Ω 1.15Ω 2.30Ω 1.64Ω
13A 2.30Ω 4.10Ω 3.53Ω 1.77Ω 3.53Ω 0.88Ω 1.77Ω 1.18Ω
16A 2.15Ω 3.48Ω 2.87Ω 1.44Ω 2.87Ω 0.72Ω 1.44Ω 1.26Ω
20A 1.58Ω 2.65Ω 2.30Ω 1.15Ω 2.30Ω 0.57Ω 1.15Ω 0.82Ω
25A 1.27Ω 2.11Ω 1.84Ω 0.92Ω 1.84Ω 0.46Ω 0.92Ω 0.61Ω

Rating

The most complete Multifunction testers also have such above Zs limit table implemented
in their firmware, so that the verification of the overcurrent protection is automatically
made by comparing the measured value of Loop impedance and the Zs limit of the table.
Note :

Below is a practical example of verification of the protection by MCB in a TN system
according to the international Standard IEC 60364.

32A 0.84Ω 1.44Ω 1.44Ω 0.72Ω 1.44Ω 0.36Ω 0.72Ω 0.51Ω
35A 0.74Ω 1.36Ω -- -- -- -- -- --
40A 0.72Ω 1.21Ω 1.15Ω 0.57Ω 1.15Ω 0.28Ω 0.57Ω 0.41Ω
50A 0.49Ω 0.87Ω 0.92Ω 0.46Ω 0.92Ω 0.23Ω 0.46Ω 0.33Ω
63A 0.42Ω 0.72Ω 0.73Ω 0.36Ω 0.73Ω 0.18Ω 0.36Ω 0.26Ω
80A 0.27Ω 0.51Ω 0.58Ω 0.29Ω 0.58Ω 0.15Ω 0.29Ω 0.20Ω

100A 0.22Ω 0.39Ω 0.47Ω 0.23Ω 0.47Ω 0.12Ω 0.23Ω 0.16Ω

Applicable Zs limit table varies country by country. KEW 6516/ 6516BT automatically
shows the appropriate Zs limit table corresponding to the selected language.

gG Fuses

0.4s 5 s

B C C D D K

0.4 & 5s

0.4s 5s 0.4s 5s 0.4s

MCBs

Fig.10-4

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Max value of Zs for this example is 1.44Ω (MCB 16A, characteristic C), the instrument
reads 1.14Ω (or 202A on Fault current range) it means that the condition

Zs x Ia ≤ Uo is respected.

In fact the Zs of 1.14Ω is less than 1.44Ω (or the Fault current of 202A is more than Ia
of 160A).
In other words, in case of fault between phase and earth, the wall socket tested in this
example is protected because the MCB will trip within the disconnection time required.

(2) Principles of the measurement of line impedance and PSC

The method for measuring Line – neutral impedance and line-line impedance is exactly
the same as for earth fault loop impedance measurement with the exception that the
measurement is carried out between line and neutral or line and line.

Prospective short circuit or fault current at any point within an electrical installation
is the current that would flow in the circuit if no circuit protection operated and a
complete (very low impedance) short circuit occurred. The value of this fault current
is determined by the supply voltage and the impedance of the path taken by the fault
current. Measurement of prospective short circuit current can be used to check that the
protective devices within the system will operate within safety limits and in accordance
with the safe design of the installation. The breaking current capacity of any installed
protective device should be always higher than the prospective short circuit current.

Fig.10-5

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10.2 Measurement method for LOOP high current

At L-PE measurement,

LCD display and function switches

Switches measurement mode:

F1

L-PE or L-N/L-L
Selects resolution 0.01Ω or 0.001Ω

F2

(In case of L-PE)

F3 Selects test lead (0.001ΩRes)

F4 Limit value setting

Measured value

LOOP limit value

PFC or
PSC value

(1) Select LOOP HIGH function with the rotary switch.
(2) Connect the test lead into the instrument. (Fig. 10-7 or Fig. 10-8)

L PE N

or

RED GREEN

BLUE

Fig. 10-7 For L-PE and L-N test

L N

RED BLUE

Mains voltage

Wiring check

Fig.10-6

no need to use N
terminal.

Fig. 10-8 For L-N and L-L test

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(3) Press the F1 switch and select L-N to measure L-N/L-L loop impedance or select

<48V

48 – 300V

>300V

L-PE to measure earth loop impedance.

・Press F2 switch and select the resolution either 0.01Ω or 0.001Ω at L-PE test.
・Display changes automatically as follows depending on the applied voltages while

LOOP(L-N/L-L) is selected.

LOOP

L-N/L-L

(4) Press F4 switch to enter the setting mode for limit value.
Please refer to "10.4 Loop limit value".

(5) Connection
Connect KEW 6516/ 6516BT to the distribution system to be tested with reference to

Fig. 10-12, 10-13, 10-14, and 10-15.

(6) Wiring Check
After the connection, ensure that the symbols for Wiring check on the LCD are in the

status indicated in Fig.10-10 before pressing the test switch.

FUNCTION L-PE○ L-N○

L-PE

0.01ΩRes

L-N L-L

（　　 ）0.001ΩRes

L-N/L-L

LOOP

Fig.10-9

◉ ◉ ○

or

◉ ○ ○
◉ ◉ ○

or

○ ◉ ○

Fig. 10-10

LOOP

○

If the status of the symbols for Wiring check differ from Fig.10-10 or
indicated on the LCD, DO NOT PROCEED AS THERE IS INCORRECT WIRING. The
cause of the fault must be investigated and rectified.

When the instrument is first connected to the system, it will display the line-earth voltage
(mode L-PE) or line-neutral voltage (mode L-N/ L-L) which is updated every 1s. If this
voltage is not normal or as expected, DO NOT PROCEED.

○ symbol is

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(7) Test lead selection (L-PE0.001ΩRes)
In case of L-PE0.001ΩRes, use F3 switch to select the test lead to be used. When

0.001ΩRes, the resistance of the test lead to be used affects the measured result;
therefore, test lead selection is effective to reduce errors in results. Select either
Model 7218A Mains test lead or Model 7246 (Distribution board test lead).

Mains lead is selected. Distribution board lead is selected.

Fig.10-11

(8) Measurement
Press the test switch. A beep will sound as the test is conducted and the value of

loop impedance will be displayed. When LOOP limit value has been set, the LCD
shows "✓" when the measured value is lower than the limit value and "X" if the value
exceeds the limit value. The " ! " symbol appears when the measured result exceeds
the measuring range, and the upper limit of the measuring range is smaller than the
reference value: it means unjudgeable.

● If the display shows '>' then this usually means the value measured exceeds the

range.

Fig. 10-12 Connection for using Outlet

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Fig. 10-13 Connection for distribution

Fig. 10-14 Connection for Line – Neutral measurement

Fig. 10-15 Connection for Line – Line measurement

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The test switch may be pressed down and turned clockwise to lock it for auto-test. In

M

PFC or

e

M

L

this auto mode, when using distribution board lead Model 7246, tests are conducted by
simply disconnecting and reconnecting the red phase prod of the Model 7246 avoiding
the need to physically press the test switch i.e. 'hands free'.

● Measured result may be influenced depending on the phase angle of the distribution

system when making measurement near a transformer and the result may lower than
the actual impedance value. Errors in measured result are as follows.

System Phase Difference Error (approx.)

10° -1.5%
20° -6%
30° -13%

● If the symbol (

automatic cut out circuits have operated. Allow the instrument to cool down before
proceeding. The overheat circuits protect the test resistor against heat damage.

10.3 Measurement method for LOOP ATT (Anti trip technology)

LCD display and function switches

easured value

PSC valu

Noise indicator

) appears, it means that the test resistor is too hot and the

F1 Switches 3-wire and 2-wire test

F2 Turns on/ off pulse function

F3 N/A

F4 Limit value setting

OOP limit value

ains voltage

Wiring check

Fig. 10-16

(1) Press the Power switch and turn on the instrument. Turn the rotary switch and set it

to the LOOP ATT position.

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(2) Connect the test lead to the instrument. (Fig. 10-17 or Fig. 10-18)

L

L PE N

RED

(3) Press F1 switch and select either L-PE 2W (2-wire) or L-PE 3W (3-wire) test.
(4) Pulse function can be turned on or off with F2 switch.
When pulse function is on (enabled), a high current is applied in a short period - RCD

won't trip - before starting LOOP measurement. This pulse function can remove the
oxidized coating of the circuit under test and contribute accurate measurements.

When pulse function is enabled, some RCDs may trip depending on their sensitivity. In
such a case, turn off the pulse function.

(5) Press F4 switch to enter the setting mode for limit value.
Please refer to "10.4 Loop limit value".

GREEN

Fig. 10-17 For L-PE 3-wire test

RED

Fig. 10-18 For L-PE 2-wire test

BLUE

PE

GREEN

# CAUTION

or

(6) Connection
Connect KEW 6516/6516BT to the distribution system to be tested with reference to

Fig. 10-20, 10-21 and 10-22.

(7) Wiring Check
After the connection, ensure that the symbols for Wiring check on the LCD are in the

status indicated in Fig.10-19 before pressing the test switch.

FUNCTION

L-PE 3W ◉ ◉ ○
L-PE 2W ◉ ○ ○

If the status of the symbols for Wiring check differ from Fig. 10-19 or
indicated on the LCD, DO NOT PROCEED AS THERE IS INCORRECT WIRING. The
cause of the fault must be investigated and rectified.

L-PE○ L-N○

Fig. 10-19

○

○ symbol is

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When the instrument is first connected to the system, it will display the line-earth voltage
(mode L-PE) which is updated every 1s. If this voltage is not normal or as expected, DO
NOT PROCEED.

(8) Measurement
Press the test switch. A beep will sound as the test is conducted and the value of

loop impedance will be displayed. When LOOP limit value has been set, the LCD
shows "✓" when the measured value is lower than the limit value and "X" if the value
is higher than the limit value.

● If the display shows '>' then this usually means the value measured exceeds the

range.

Fig. 10-20 3-wire test (Connection for using outlet)

Fig. 10-21 3-wire test (Connection for distribution)

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Fig. 10-22 L-PE 2-wire test

● ATT mode enables a measurement without tripping the RCDs with the rated residual

current of 30mA or more.

● Measurement in ATT mode requires longer time than that is required for the other

measurements (approx. 8 sec). When measuring a circuit with a large electrical
noise, the 'Noise' Message is displayed on the LCD and the measurement time will be
extended.

Noise indicator shows the noise size in three levels. Noise size affects the

measurement Time.

Level 1 Level 2 Level 3

If the 'NOISE' symbol is displayed on the LCD, it is recommended to disable the ATT
mode and take a measurement (RCDs may trip).

● At L-PE 3W measurement, when a LOOP impedance between L-N exceeds 20Ω, the
LCD shows "L-N>20Ω" and the instrument doesn't make measurements. In this case,
set the range to "LOOP HIGH" or test with L-PE 2W ATT.

● If a high voltage exists between N-PE at L-PE 3W test, the LCD shows "N-PE HiV"
and the instrument doesn't make measurements. In this case set the range to "LOOP
HIGH" or test with L-PE 2W ATT.

The test switch may be turned clockwise to lock it down. In this auto mode, when using
distribution board lead Model 7246, tests are conducted by simply disconnecting and
reconnecting the red phase prod of the Model 7246 avoiding the need to physically
press the test switch i.e. 'hands free'.

Fig. 10-23 Noise indicator

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● Measured result may be influenced depending on the phase angle of the distribution
system when making measurement near a transformer and the result may lower than
the actual impedance value. Errors in measured result are as follows.

System Phase Difference Error (approx.)

10° -1.5%

20° -6%

30° -13%

● If the symbol (
automatic cut out circuits have operated. Allow the instrument to cool down before
proceeding. The overheat circuits protect the test resistor against heat damage.

10.4 Loop limit value

To set a loop limit value, press F4 switch in the stand-by mode at LOOP test. The
following figure shows the setting mode screen.

Fig. 10-24 LOOP LIMIT setting screen

)appears, this means that the test resistor is too hot and the

・The table below shows the setting parameters.

(a) Protection type Type of protective device gG FUSE, MCB(B,C,D,K), RCD, OFF

(b) In

(c) Time or Uc

(d) Factor Margin of threshold value

Limit value setting procedures are shown below.
(Press ESC switch to one step back during the process.)

(1) Press F1(▲) or F2(▼) on LOOP LIMIT setting screen to move the cursor on the item

to be set, and then press ENTER switch.

(2) The LCD shows the selectable items. Press F1(▲) or F2(▼) and confirm the

selection with ENTER switch. For some items, F3(
used.

(3) When changes are done, press ESC to return to LOOP test screen.

Rated current of
protective device

Trip time of protective
device

In: 6 - 100 A
IΔn: 30 mA-1000 mA

For RCD, Uc limit value setting

Limit value is determined by the
following formula.
Limit = specified value x factor

) and F4( ) switches are also

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Selectable parameters and reference values for limit value are as shown below.

●Loop Limit value for fuse protection

Protection

Type

TIME 0.4s 5s

6A 5Ω 8.84Ω 7.67Ω 3.83Ω 7.67Ω 1.92Ω 3.83Ω 2.73Ω
10A 2.87Ω 5Ω 4.6Ω 2.3Ω 4.6Ω 1.15Ω 2.3Ω 1.64Ω
13A 2.3Ω 4.1Ω 3.53Ω 1.77Ω 3.53Ω 0.88Ω 1.77Ω 1.18Ω
16A 2.15Ω 3.48Ω 2.87Ω 1.44Ω 2.87Ω 0.72Ω 1.44Ω 1.26Ω
20A 1.58Ω 2.65Ω 2.3Ω 1.15Ω 2.3Ω 0.57Ω 1.15Ω 0.82Ω

In

Rating

●Loop Limit value for RCD protection

Note: Displayed Loop Limit value may not be the same as listed above depending on

25A 1.27Ω 2.11Ω 1.84Ω 0.92Ω 1.84Ω 0.46Ω 0.92Ω 0.61Ω
32A 0.84Ω 1.44Ω 1.44Ω 0.72Ω 1.44Ω 0.36Ω 0.72Ω 0.51Ω
35A 0.74Ω 1.36Ω -- -- -- -- -- -­40A 0.72Ω 1.21Ω 1.15Ω 0.57Ω 1.15Ω 0.28Ω 0.57Ω 0.41Ω
50A 0.49Ω 0.87Ω 0.92Ω 0.46Ω 0.92Ω 0.23Ω 0.46Ω 0.33Ω
63A 0.42Ω 0.72Ω 0.73Ω 0.36Ω 0.73Ω 0.18Ω 0.36Ω 0.26Ω
80A 0.27Ω 0.51Ω 0.58Ω 0.29Ω 0.58Ω 0.15Ω 0.29Ω 0.2Ω

100A 0.22Ω 0.39Ω 0.47Ω 0.23Ω 0.47Ω 0.12Ω 0.23Ω 0.16Ω

IΔn (mA)

the countries and regions.

gG Fuse

UC Lim. 50V 25V

30mA 1667Ω 833Ω
100mA 500Ω 250Ω
300mA 167Ω 83Ω
500mA 100Ω 50Ω

1000mA 50Ω 25Ω

B C D K

0.4 & 5s

0.4s 5s 0.4s 5s 0.4s

MCB

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11. RCD tests

11.1 Principles of RCD measurement

The RCD tester is connected between phase and protective conductor on the load side
of the RCD after disconnecting the load.
A precisely measured current for a carefully timed period is drawn from the phase and
returns via the earth, thus tripping the device. The instrument measures and displays
the exact time taken for the circuit to be opened.
An RCD is a switching device designed for breaking currents when the residual current
attains a specific value. It works on the basis of the current difference between phase
currents flowing to different loads and returning current flowing through the neutral
conductor (for a single-phase installation). In the case where the current difference is
higher than the RCD tripping current, the device will trip and disconnect the supply from
the load.
There are two parameters for RCDs; the first due to the shape of the residual current
wave form (types AC and A) and the second due to the tripping time (types G and S).

●

RCD type AC will trip when presented with residual sinusoidal alternating currents
whether applied suddenly or slowly rising. This type is the most frequently used on
electrical installations.

●

RCD type A will trip when presented with residual sinusoidal alternating currents
(similar to type AC) and residual pulsating direct currents whether suddenly applied
or slowly rising.

●

RCD Type F will trip when presented with residual sinusoidal alternating currents
at the rated frequency, residual pulsating direct currents and composite residual
currents.

  Tests of RCD type F with F KEW 6516/6516BT use halfwave rectified current as

same as testing Type A RCD.

●

RCD type B can detect residual sinusoidal alternating currents up to 1000 Hz,
residual pulsating direct currents as well as smooth DC residual currents.

● RCD type G. In this case G stands for general type (without tripping time delay) and

is for general use and applications.

●

RCD type S where S stands for selective type (with tripping time delay). This type
of RCD is specifically designed for installations where the time delay characteristic is
required.

● RCD Type EVs are designed specially for EV (electric vehicle) charging systems.

They trip by 6mA smooth DC residual currents.

Given that when the protective device is an RCD, Ia is typically 5 times the rated
residual operating current IΔn, then the RCD must be tested recommending the
tripping time, measured by RCD testers or multifunction testers, shall be lower than the
maximum disconnecting times required in IEC 60364-41 at 230V / 400V AC (see also
LOOP section) that are:

TT system 200ms for final circuits up to 63A for socket, or up to 32A

TN system 400ms

TT system 1000ms for distribution circuits and circuits above mentioned

TN system 5s

for fixed connected loads

over 63A and 32A.

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However, it is also good practice to consider even more stringent trip time limits, by
following the standard values of trip times at IΔn defined by IEC 61009 (EN 61009) and
IEC 61008 (EN 61008). These trip time limits are listed in the table below for IΔn and
5IΔn:

Type of RCD IΔn 5IΔn

General(G)

Selective(S)

Examples of instrument connections

Practical example of 3-phase + neutral RCD test in a TT system.

300ms

max allowed value

500ms

max allowed value

130ms

min allowed value

40ms

max allowed value

150ms

max allowed value

50ms

min allowed value

Fig. 11-1

Practical example of single phase RCD test in a TN system.

Fig. 11-2

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Practical example of RCD test with distribution leads.

M

v

L

Pr

Fig. 11-3

11.2 Principles of Uc measurement

Ground being imperfect in the Fig. 11-1, when R exists, when a fault current flows to R,
electric potential occurs. There is a possibility the person contacting in this imperfect
ground, it calls the voltage, which it occurs in the human body of this time, called Uc.
When with the Uc Test letting flow IΔN to the RCD, the Uc is calculated.
Uc voltage is calculated based on the Rated Residual Current (IΔN) with the
impedance measured.

11.3 Measurement method for RCD

LCD display and function switches

F1 Measurement mode setting

(X1/2, X1, X5, Ramp, Auto,Uc)

F2 IΔn setting

F3 RCD Type setting

AC-G

AC-S
A-G A-S
F-G F-S
B-G B-S
TYPE EV

F4

easured

alue

Phase Setting (0° (+)or 180° (-))

eset UL value

-PE voltage

Wiring check

Fig. 11-4

(1) Press the Power switch and turn on the instrument. Turn the rotary switch and set it

to the RCD position.

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(2) Connect the test lead to the instrument. (Fig. 11-5)

At AC/ A/F measurement,

L PE N

or

no need to use N terminal.

RED GREEN

(3) Press the F1 switch and select any desired measurement mode.

X1/2 For testing RCD to verify that they are not too sensitive.

X1 For measuring the trip time.
X5 For testing at IΔn X5

RAMP(

AUTO

Uc For measuring Uc

(4) Press the F2 switch to set Rated Tripping Current (IΔn) to the rated trip current of

the RCD.
(5) Press F3 switch to select the RCD type.
Refer to "11.1 Principles of RCD measurement" for the details of RCD type.
(Except for Uc measurement)
(6) Press (F4) to select phase at which the test current should start.
(Except for Uc measurement)

*UL value change

As a UL value, 25V or 50V is selectable. Refer to "6. Setup mode" in this manual and
select either of them.

(7) Connect the test leads to the circuit to be tested. (Fig. 11-1,11-2, and 11-3)
(8) Wiring Check
After the connection, ensure that the symbols for Wiring check on the LCD are in the

status indicated in Fig.11-6 before pressing the test switch.

RCD TYPE L-PE○ L-N○

AC/A/F

If the status of the symbols for Wiring check differ from Fig. 11-6 or
indicated on the LCD, DO NOT PROCEED AS THERE IS INCORRECT WIRING. The
cause of the fault must be investigated and rectified.

BLUE

Fig. 11-5 For RCD test

For measuring the tripping level in mA.

)

For automatic measurement in the following
sequence: X1/2(0°), X1/2(180°), X1(0°),X1 (180°), X5(0°), X5(180°)

○

◉ ◉ ○

or

◉ ○ ○

B/EV ◉ ◉ ○

Fig. 11-6

○ symbol is

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When the instrument is connected to the system for the first time, it will display the line­earth voltage (mode L-PE) which is updated every 1s. If this voltage is not normal or as
expected, DO NOT PROCEED.

NOTE: This is a single phase (230V AC) instrument and under no circumstances should

it be connected to 2- phases or a voltage exceeding 230VAC+10%.

If the input voltage is greater than 260V the display will indicate '>260V' and

RCD measurements can not be made even if the test switch is pressed.

(9) RCD Measurement
Press the test switch. A beep will sound as the test is conducted and the measured

results are displayed.

● X1/2...................The Breaker should not trip.

● X1......................The Breaker should trip.

● X5......................The Breaker should trip.

● Auto Ramp(

● Uc......................Uc values are displayed.

In case of RCD type S test, you need to wait 30 sec. before starting a test: this waiting
time is to reduce the influence of the previous test.

(10) Press the F4(0°(+)/180°(-)) switch to change the phase and repeat step (1).

The test switch may be turned clockwise to lock it down. In this auto mode, when using
distribution board lead Model 7246, tests are conducted by simply disconnecting and
reconnecting the red phase prod of the Model 7246 avoiding the need to physically
press the test switch i.e. 'hands free'.

● If the symbol (

automatic cut out circuits have operated. Allow the instrument to cool down before
proceeding. The overheat circuits protect the test resistor against heat damage.

● Be sure to return the tested RCD to the original condition after the test.

● When the Uc voltage rises to UL value or greater, the measurement is automatically

suspended and "Uc > UL" is displayed on the LCD.

● If " IΔn" setting is greater than the rated residual current of the RCD, the RCD will

trip and "no" may be displayed on LCD.

● If a voltage exists between the protective conductor and earth, it may influence the

measurements.

● If a voltage exists between neutral and earth, it may influence the measurements,

therefore, the connection between neutral point of the distribution system and earth
should be checked before testing.

● If leakage currents flow in the circuit following the RCD, it may influence the

measurements.

● The potential fields of other earthing installations may influence the measurement.

● Special conditions of RCDs of a particular design, for example S- type, should be

taken into consideration.

● The earth electrode resistance of a measuring circuit with a probe shall not exceed

the earth electrode resistance values, specified in the table below RCD-related
description, in 5.4 Operating uncertainty .

● Equipment following the RCD, e.g. capacitors or rotating machinery, may cause a

significant lengthening of the measured trip time.

)..The Breaker should trip. The tripping current should be displayed.

)appears, this means that the test resistor is too hot and the

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11.4 Auto test

Measurements are automatically performed under the Auto Test function in the following
sequence: X1/2(0°), X1/2(180°), X1(0°),X1 (180°), X5(0°), X5(180°).

(1) Press F1 to select Auto.
(2) Press F2 & F3 to select IΔn & RCD type.
(3) KEW 6516/ 6516BT performs RCD test in the sequence described above.
(4) When an RCD trips, turn it back on. Then a next test begins automatically.
(5) The LCD shows results as follows.

Fig. 11-7

11.5 VAR (variable current value) function

At RCD test with KEW 6516/6516BT, any I∆n value – between 10mA and 1000mA - is

selectable. However, X5 test or depending on the selected RCD test settings, variable
range of current value will be limited.

Follow the procedures below to change the current value.
(Pressing ESC switch during the changing process can one step back.)
(1) Press F1 & F3 to select measurement mode & RCD type.
(2) Press F2 switch to select "VAR".
(3) The LCD shows current value 2 sec. (Fig. 11-8). Press F1 (SET) switch within this

2 sec. (If 2 sec or longer are elapsed without pressing the switch, press F2 switch

again to reshow Fig. 11-8 screen.)
(4) The LCD shows current value changing screen (Fig. 11-9). Press F3(

select the digit to be changed and alter the values with F1(▲) or F2(▼).
(5) Press ENTER to confirm the change. Then the screen returns to stand-by mode for

RCD test.

) or F4( ) to

Fig. 11-8 Fig. 11-9

Note: At VAR test, X1/2, X1, and X5 tests are performed; these tests are not available at

Uc, AUTO, and RAMP tests.

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11.6 EV RCD

H(C)Current

When selectingEVfor RCD TYPE, the instrument can test RCDs for EV charger

which trip by 6 mA DC: x1, RAMP(

● At RAMP, current is steadily increased up to 6 mA DC (100%).
When it reaches to 6 mA DC, the current is kept for 10 sec. (Comply with

IEC62752)

● At AUTO TEST, the instrument performs tests at 6 mA DC and ×1/2, ×1, and ×5

tests at 30 mA AC as shown below.

DC 6 m A(+) → DC6mA(-) → X1/2(0°) → X1/ 2(18 0°) → X1(0°) →
X1(18 0 °) →X5(0°) → X5(180°).

), and AUTO TEST are selectable.

AC30mA            

Fig. 11-10

12. Earth tests

12.1 Principles of earth measurement

This Earth function is to test power distribution
lines, in-house wiring system, electrical
appliances etc.
This instrument makes earth resistance
measurement with fall-of-potential method,
which is a method to obtain earth resistance
value Rx by applying AC constant current
I between the measurement object E (earth
electrode) and H(C) (current electrode), and
finding out the potential difference V between E
and S(P) (potential electrode).
Rx = V / I

12.2 Earth resistance measurement

# WARNING

The instrument will produce a maximum voltage of about 50V between terminals
E-H(C) in earth resistance function. Take enough caution to avoid electric shock
hazard.

# CAUTION

When measuring earth resistance, do not apply voltage between measuring terminals.

Constant Current Generator

Voltmeter

S(P)Potential

E(Earth)

Fig. 12-1

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12.3 Measurement method for earth

(1) Press the Power switch and turn on the instrument. Turn the rotary switch and set it

to the EARTH position.
(2) Press F1 switch to select 3W (3-wire precise measurement) or 2W (2-wire simplified

measurement).
(3) Connect the test lead into the instrument. (Fig. 12-2, Fig. 12-3)

Red Green Yellow

H(C) E S(P)

Fig.12-2 For 3W test (Precise measurement)

H(C) E

Fig.12-3 For 2W test (Simplified measurement)

(4)Connection

3W test (Precise measurement)

Stick the auxiliary earth spikes S(P) and H(C) into the ground deeply. They should be
aligned at an interval of 5-10m from the earthed equipment under test. Connect the
green wire to the earthed equipment under test, the yellow wire to the auxiliary earth
spike S(P) and the red wire to the auxiliary earth spike H(C) from terminals E, S(P) and
H(C) of the instrument in order.

H(C) terminal
Red cord of Model 7228
E terminal
Green cord of Model 7228
S(P) terminal
Yellow cord of Model 7228

H(C) terminal
Red cord of Model 7246, or
Model 7281 Remote Test Lead
E terminal
Green cord of Model 7246

Note:

● Make sure to stick the auxiliary earth spikes in the moist part of the soil. Give enough

water where the spikes have to be stuck into the dry, stony or sandy part of the earth
so that it may become moist.

● In case of concrete, lay the auxiliary earth spike down and water it, or put a wet dust

cloth etc. on the spike when making measurement.

Fig.12-4

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2W test (Simplified measurement)

Use this method when the auxiliary earth spike cannot be stuck. In this method, an
existing earth electrode with a low earth resistance, such as a metal water pipe, a
common earth of a commercial power supply and an earth terminal of a building, can be
used with two-pole method.

Fig.12-5

Rx = Re – re
Rx: True earth resistance
Re: Indicated value
re: Earth resistance of earth electrode

(5) If the "Live Circuit" warning is displayed on the LCD and/or the buzzer sounds, do

not press the test switch but disconnect the instrument from the circuit. Make the

circuit dead before proceeding.

(6) Press the test switch, the display will show the earth resistance of the circuit.

● If measurement is made with the probes twisted or in touch with each other, the

reading of the instrument may be affected by induction. When connecting the probes,
make sure that they are separated.

● If earth resistance of auxiliary earth spikes is too large, it may result in inaccurate

measurement. Make sure to stick the auxiliary earth spike in the moist part of the soil,
and ensure sufficient connections between the respective connections. High auxiliary
earth resistance may exist if "R

  ("Rs Hi" is displayed only when you press the test button to start a measurement.

It won't appear if any incidents, such as auxiliary earth spikes are disconnected,
happen during a measurement,)

● When an earth voltage of 10V or higher (400Hz: 3V) exists, measured earth

resistances may include large errors. In this case, power off the devices which is
using earth resistance under test to reduce the earth voltages.

S Hi" or "RH Hi" is displayed during measurements.

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13. Phase rotation tests

P

Voltage across the terminals and
Frequency of L1-L2 voltage

Phase sequence (Counter-clockwise)

1. Press the Power switch and turn on the instrument. Turn the rotary switch and select

the PHASE ROTAION function.

2. Insert the test leads into the instrument. (Fig.13-1)

L1 L2 L3

RED GREEN BLUE

3. Connect each test leads to a circuit. (Fig.13-2)

4. Results are displayed as follows.

hase sequence (Clockwise)

Fig.13-1

Fig.13-2

Fig. 13-3 Correct phase sequence Fig.13-4 Reversed phase sequence

● When a message "No 3-phase system" or "---" is displayed, the circuit may not be a

3-phase system or a wrong connection may have been made. Check the circuit and
the connection.

● Presence of harmonics in measurement voltages, such as an inverter power supply,

may influence the measured results.

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14. Volts

V

Voltage
f
be

Voltages
be
and

(1) Press the Power switch and turn on the instrument. Turn the rotary switch and select

the VOLTS function.
(2) Insert the test leads into the instrument. (Fig.14-1)

L1 L2 L3

or

RED GREEN BLUE

Fig.14-1

(3) Voltage value and frequency will be displayed on the LCD when applying AC voltage.

Note : A message "DC V" may be displayed when measuring AC voltages with

frequencies out of the range 45Hz - 65Hz.

oltage between L-PE

tween L-N

N-PE

Fig.14-2

requency

tween L-PE

15. Touch pad

(1)

The touch pad measures the potential between the operator and the tester's PE terminal.
A message "PE HiV" is displayed on the LCD with the audible buzzer if a potential

difference of 100V or more is present between the operator and the PE terminal at

touching the Touch pad.
(2) Touch Pad function can be enabled and disabled (ON / OFF).
See "6. Setup mode" in this manual and select ON or OFF. In case that OFF is

selected, a warning for "PE HiV" does not appear and the buzzer does not sound.
* Initial setting: ON

Note :

A message "PE HI V" may be displayed when testing inverters or measuring
voltages containing high frequencies even if a user isn't touching with the Touch Pad.

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16. Memory function

Measured result at each function can be saved in the memory of the instrument.
(MAX: 1000)

16.1 How to save the data

Save the result according to following sequence.
(Press ESC switch during the process to one step back.)

(1) When measurement is done, press MEM switch

to enter the save mode. (Fig. 16-2)

Fig.16-1

(2) Make setting for following items.

1. CIRCUIT No

2. BOARD No

3. SITE No

4. DATA No

Fig.16-2

● Press the F1(▲) or F2(▼) switch to choose the

parameter to change.

CIRCUIT No → BOARD No → SITE No → DATA No → CIRCUIT No …

● Press ENTER switch to select the parameter to be changed.

● Use F1(▲) or F2(▼) to alter the value of the parameter and confirm with ENTER

switch. The selectable range is shown in the table below.

CIECUIT No. 0-99

BOARD No. 0-99

SITE No. 0-99

DATA No. 0-999

(3) A press of F4 or MEM switch saves the measured data.

Note: Pressing ESC switch can one step back.

Data is saved.

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16.2 Recall the saved data

Save data can be displayed on the LCD according to the following sequence.
(Pressing ESC switch during the adjustment can one step back.)

(1) Hold down MEM switch 1 sec in stand-by

mode enters RECALL mode and the LCD
shows a list of the save data. (Fig. 16-3)

Fig.16-3

(2) Press ▲(F1) or ▼(F2) switch and select

the data you wish to review, and then press
ENTER. (Fig. 16-4)

Fig.16-4

(3) The selected data will be displayed. (Fig. 16-5)

Fig.16-5

(4) Press F4 (EDIT) switch to edit the parameters that have been set at saving.
The LCD display will be as follows. Change the parameters - procedures are the

same as the saving data – and overwrite and save again; however, DATA No. is
unchangeable.

Fig.16-6

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16.3 Delete the saved data

(1) To delete the saved data:
Press F3 switch in the state as Fig. 16-5 shows to delete data.
Confirmation message appears as shown below.
Press F3 switch to delete data.

Fig.16-7

(2) To delete whole data:
Press F4 switch in the state as Fig. 16-4 shows to delete all data.
Confirmation message appears as shown below.
Press F4 switch to delete all data.

Fig.16-8

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17 Transfer the stored data to PC

The stored data can be transferred to PC via Optical Adapter Model 8212USB

Fig.17-1

●How to transfer the data:

(1) Connect Model 8212USB to the USB Port

of a PC. (Special driver for Model 8212USB
should be installed. See the instruction
manual for Model 8212USB for further
details.)

(2) Insert Model 8212USB into the KEW

6516/6516BT as shown in Fig 17-2. Test
leads should be removed from the KEW
6516/ 6516BT at this time.

(3) Power on the KEW 6516/ 6516BT. (Any

function is OK.)

(4) Start special software "KEW Report" on

your PC and set the communication port.

Then click "Download" command, and the

data in the KEW 6516/ 6516BT will be transferred to your PC. Please refer to the

instruction manual of Model 8212USB and HELP of KEW Report for further details.

Fig.17-2

Note: Use "KEW Report" version 2.80 or later.
The latest "KEW Report" can be downloaded from our web site.

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18. Bluetooth communication (KEW 6516BT only)

18.1 Bluetooth communication

KEW 6516BT has a Bluetooth communication function and can exchange data with
Android/ iOS tablet devices. (Not available on KEW 6516.)
Before starting to use this function, download the special application "KEW Smart *" via
the internet.
Some functions are available only while connected to the internet. For further detail,
please refer to "18.2 KEW Smart *".

# 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 LAN devices (IEEE802.11.b/g)

may cause radio interferences, lowering of communication 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, or turn 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 the measurement 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 to establish

communication with the instrument. Please use another tablet device and try to
communicate with. If you still cannot confirm the connection, there may be some
problem with the instrument unit. Please contact 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 Map are the trademark or registered

trademark of Google Inc.

● iOS is the trademark or registered trademark of Cisco.

● Apple Store is the service mark of Apple Inc.

● In this manual, the "TM" and " ® " marks are omitted.

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18.2 KEW Smart *

The special application "KEW Smart *" is available on download site for free. (An
Internet access is required.) Please note that communication charge is incurred
separately for downloading applications and using special features of them. For your
information, "KEW Smart *" is provided on-line only.

Features of KEW Smart *:

● Remote monitoring/ checking

● Data save/ recall function

● Map display
  Measured locations can be checked on the Google Map if the saved data includes

GPS location info.

● Comment editing
  Measured result can be saved with comments.

The latest information about "KEW Smart *" can be checked with the site on Google
Play Store or App Store.

19. Auto-power-off

This instrument has auto-power-off function.
When the instrument is inactive for about 10 minutes, it turns off automatically.

Auto-power-off function doesn't work during a measurement, while applying voltage, and
Bluetooth communication (KEW 6516BT only) is being performed.

If there's no key operation for 2 min, backlight will dim automatically. Pressing any key
restores the brightness.

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20. Battery and fuse replacement

# DANGER

● Do not open the battery compartment cover if the instrument is wet.

● Do not replace batteries nor fuse during a measurement. To avoid getting electrical

shock, power off the instrument and disconnect all test leads before replacing

batteries or fuse.

● The battery compartment cover must be closed and screwed before making

measurement.

20.1 Battery replacement

Replace batteries with new ones when the battery indicator shows "
is almost empty.

# CAUTION

●Do not mix new and old batteries nor different types of batteries.

●Install batteries in correct polarity as marked inside.

(1) Power off the instrument and disconnect all test leads from the terminals.
(2) Unscrew two screws and remove the battery compartment cover. (Fig. 20-1)
(3) Replace all eight batteries with new ones at once. Observe correct polarity when

inserting new batteries, Battery: Size AA Alkaline battery (LR6) x 8 pcs.

(4) Attach the battery compartment cover, and secure it with the two screws,

Note:
Clock setting will be cleared if no batteries were inserted in the instrument 10 min. or
longer. When battery replacement is required, be careful not to exceed this period. If the
clock setting is cleared and restored to the default, please do the setting again.

"; battery level

20.2 Fuse replacement

The continuity test circuit is protected by a 600V 0.5A HRC ceramic type fuse situated in
the battery compartment, together with a spare.
Fuse : F 0.5A 600V (Φ6.3 x 32mm)
SIBA 7009463.0,5

● Procedures
(1) If the instrument fails to operate in the continuity test mode, first disconnect the test

leads from the instrument.
(2) Unscrew two screws and remove the battery compartment cover. (Fig. 20-1)
(3) Take out the fuse and check for continuity with another continuity tester. If the fuse

has blown, replace it with the spare fuse.
(4) Attach the battery compartment cover, and secure it with the two screws.

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Screw

­+

-

+

+

Spare Fuse

-

-

+

Fuse

Fig.20-1

21. Servicing

If this tester should fail to operate correctly, return it to your distributor stating the exact
nature of the fault. Before returning the instrument ensure that:
(1) The leads have been checked for continuity and signs of damage.
(2) The continuity mode fuse (situated in the battery compartment) has been checked.
(3) The batteries are in good condition.

Please remember to give all the information possible concerning the nature of the
fault, as this will mean that the instrument will be serviced and returned to you
more quickly.

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22. Case and strap assembly

Match the hole of the Buckle and the protrusion

Pass the strap belt down through

Pass the strap through the buckle,

Fig. 22-3

Fig. 22-4

Fig. 22-1

Lead the shoulder pad through the

Attach the strap belt according to the following procedures. By hanging the instrument
around the neck, both hands will be left free for testing.

(1) Attach the Buckle to the KEW 6516/6516BT as shown in Fig.22-1.

at the side face of KEW 6516/6516BT and slide
it upwards.

(2) How to attach the shoulder pad:

strap belt.

Fig. 22-2

(3) How to install the strap belt: (4) How to fasten the strap belt:

the buckle from the top, and up.

adjust the strap for length and secure.

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