KYORITSU 4118A, 4116A, 4120A Instruction Manual

MODEL 4118A

DIGITAL PSC-LOOP TESTER

INSTRUCTION MANUAL

KYORITSU ELECTRICAL INSTRUMENTS

WORKS，LTD.

CONTENTS

1. SAFE TESTING .................................................................................. 1

2. PROCEDURE OF REMOVING COVER ........................................... 4

3. FEATURES .......................................................................................... 5

　3.1 Instrument Layout ........................................................................ 5

　3.2 Test Lead ...................................................................................... 6

　3.3 Features ........................................................................................ 7

4. SPECIFICATIONS .............................................................................. 9

5. OPERATING INSTRUCTIONS ......................................................... 10

　5.1 Initial Checks ................................................................................ 10

　5.2 Measurement of the Loop Impedance ...................................... 11

　5.3 Measurement of Prospective Short Circuit Current .............. 12

6. DETAILED EXPLANATION ............................................................ 13

　6.1 Measurement of Fault Loop Impedance and

Prospective Fault Current ........................................................ 13

　6.2 Measurement of OLD-TT System .............................................. 18

　6.3 Measurement of Line Impedance and

Prospective Short Circuit Current .......................................... 19

7. SERVICING ................................................................................... 20

8. CASE AND STRAP BELT ASSEMBLY .......................................... 20

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1

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1. SAFE TESTING

#

Electricity is dangerous and can cause injury and death. Always treat it
with the greatest of respect and care. If you are not quite sure how to
proceed, stop and take advice from a qualified person. This instruction
manual contains warnings and safety rules which must be observed by
the user to ensure safe operation of the instrument and retain it in safe
condition. Therefore, read through these operating instructions before
using the instrument.

IMPORTANT:

1. This instrument must only be used by a competent and trained
person and operated in strict accordance with the instructions.
KYORITSU will not accept liability for any damage or injury caused
by misuse or non-compliance with the instructions or with the safety
procedures.

2. It is essential to read and to understand the safety ru

les contained

in the instructions or with the safety procedures.

3. The symbol

#

indicated on the instrument means that the user

must refer to the related sections in the manual for safe operation of
the instrument. Be sure to carefully read instructions following each

symbol # in this 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 a

minor injury or instrument damage.

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2

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　 #

DANGER

●　 The instrument is to be used only in its intended applications or
conditions. Otherwise, safety functions equipped with the
instrument will not work, and instrument damage or serious personal
injury may occur. Verify proper operation on a known source before
use or taking action as a result of the indication of the instrument.

● 　 This instrument is intended only for use in single phase operation at
230V +10% -15% AC phase to earth or for use in OLD-TT system
phase to neutral.

●　 When conducting tests do not touch any exposed metalwork
associated with the installation. Such metalwork may become live
for the duration of the test.

●　 When testing, always be sure to keep your fingers behind the safety
barriers on the test leads.

●　 Be sure to remove the test lead from the mains power supply
promptly after measurement. Do not leave the instrument connected
to the mains power supply for a long time.

　 #

WARNING

●　 The instrument is to be used only in its intended applications.
Understand and follow all the safety instructions contained in the
manual. Failure to follow the 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 this cautionary note.

● 　

Never open the instrument case

- there are dangerous voltages
present. If a fault develops, return the instrument to your distributor
for inspection and repair.

● 　 If the overheat symbol appears in the display (

) disconnect the

instrument from the mains supply and allow to cool down.

● 　 If abnormal conditions of any sort are noted (such as a faulty
display, unexpected readings, broken case, cracked test leads, etc)
do not use the tester and return it to your distributor for repair.

● 　 Never attempt to use the instrument if the instrument or your

hand

is wet.

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3

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　 #

CAUTION

● 　 For those testers without the D-LOK circuitry (models 4118A) all

RCD's (RCCB, ELCB) in the circuit must be by-passed for the
duration of the test (except on loop-2000Ω range).

　 Do not operate the RCD Test Button with the RCD by-passed.

● 　 During testing it is possible that there may be a momentary

degradation of the reading due to the presence of excessive
transients or discharges on the electrical system under test.
Should this be observed, the test must be repeated to obtain a
correct reading. If in doubt, contact your distributor.

● 　 Use a damp cloth and detergent for cleaning the instrument. Do

not use abrasives or solvents.

● Measurement categories(Over-voltage categories)

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

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4

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2. PROCEDURE OF REMOVING COVER

Model 4118A have a dedicated cover to protect against an impact
from the outside and prevent the operation part, the LCD and the
connector socket from becoming dirty. The cover can be detached
and put on the back side of the main body during measurement.

Fig. 2

2.1 Method of removing the cover

2.2 Method of housing the cover

Fig. 1

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5

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3. FEATURES

3.1 Instrument Layout

1............ LCD display

2............ Wiring check LEDs

3............ Test button

4............ Range switch

5............ Connector

LCD

Connector

Fig. 3

　 #

DANGER

● 　 Use original test lead only.

● 　 Max. allowed voltage between mains test terminals and ground is
300V.

● 　 This instrument is intended only for use in single phase operation
at 230V +10% -15% AC phase to earth or for use in OLD-TT
system phase to neutral.

①

②

③

④

⑤

Wiring correct

（Green LED's）

Reversed L/N terminals

（Red LED）

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6

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3.2 Test Lead

The instrument is supplied with Model 7125 lead at socket outlets and Model
7121B distribution board lead.

(1) Model 7125

Mains lead mentioned in this instruction manual is Model 7125(EU)
European SCHUKO plug, however, there are some other types for the
areas, and the shipping is made along with the suitable plug-shaped
cable according to the areas of the globe as follows;
Model 7123 (AU) for Australian plug
Model 7124 (UK) for British plug (13A)
Model 7126 (SA) for South African plug

(2) Model 7121B

Black-Neutral

Red-Phase

Green-Earth

Fig.4

The loop impedance of this instrument is adjusted to show the true value by
using the attached mains lead (either of Models 7123 through 7126) prior
to the shipment.
However, when the attached test lead for distribution board Model 7121B
is used, the total internal resistance shows approx. 0.1Ω bigger than those
of other mains lead due to the internal fuse resistance. Therefore, when
measurement is taken by using the Model 7121B, the measured value
between PHASE-EARTH shows approx. 0.1Ω bigger than the true value.
PHASE make sure that 0.1Ω subtracted from the measured value leaves
the true value in case of using the test lead of this distribution board.
As for the PSC range, use the following equation and divide supply voltage
by loop impedance, therefore, the measured value shows smaller than the
true value contrary to the case of the case of loop impedance range.

● PSC(A) = Supply Voltage(V) / Loop Impedance(Ω)