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MODEL  4118A

DIGITAL PSC-LOOP TESTER

INSTRUCTION  MANUAL

KYORITSU  ELECTRICAL  INSTRUMENTS  

WORKS,LTD.

Summary of Contents for 4118A

Page 1: ...MODEL 4118A DIGITAL PSC LOOP TESTER INSTRUCTION MANUAL KYORITSU ELECTRICAL INSTRUMENTS WORKS LTD ...

Page 2: ... 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 ...

Page 3: ...he 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 rules 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 sa...

Page 4: ...easurement 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 ...

Page 5: ...asuring 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...

Page 6: ...gainst 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 ...

Page 7: ...nnector 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 Wiring correct Green LED s Reversed L N terminals Red LED ...

Page 8: ...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...

Page 9: ...ical safety part Barrier provides protection against electrical shock and ensuring the minimum required air and creepage distances 3 3 Features 3 3 1 Test Range Function LOOP 0 19 99Ω 0 199 9Ω 0 1999Ω PSC 0 199 9A 0 1999A 0 19 99kA 3 3 2 Applied Standards Instrument operation IEC 61557 1 IEC61557 3 Safety IEC 61010 1 2 030 CATⅢ 300V instrument IEC 61010 031 CAT Ⅲ 300V test lead Protection degree I...

Page 10: ... more than 260V VL PE Hi is shown on the display 15mA Loop measurement Loop impedance 2000 Ω range measurement is carried out with low test current 15mA The current will not cause tripping out involved RCD even the one with the lowest nominal differential current 30mA Display The liquid crystal display has 3 1 2 digits with a decimal point and units of measurement Ω A kA V Manual and Autotest mode...

Page 11: ...ndensation Symbols used on the Equipment protected throughout by DOUBLE INSULATION or REINFORCED INSULATION Caution refer to accompanying instruction manual and humidity and humidity instrument Loop Impedance Prospective Short circuit Current Voltage Range 20 Ω 200 Ω 2000 Ω Measuring range 0 00 19 99 Ω 0 0 199 9 Ω 0 1999 Ω Nominal test current at 0 Ω external loop 25A 20ms 2 3A 40ms 15mA 280ms Acc...

Page 12: ...onditions exist DO NOT PROCEED WITH TESTING Lead Plug Fig 5 Operating Instrumental Uncertainty of Loop Impedance 61557 3 Range 20 Ω 200 Ω 2000 Ω Measuring range to keep operating error 0 35 19 99 Ω 20 0 199 9 Ω 200 1999 Ω Maximum percentage operating instrumental uncertainty 30 The influencing variations used for calculating the operating instrumental uncertainty are denoted as follows Temperature...

Page 13: ...orrect wiring of the power supply line 3 Voltage Measurement When the instrument is first connected to the system it will display the phase neutral voltage which is updated every 1s This mode is cancelled whenever the test button is pressed If this voltage is not normal or as expected DO NOT PROCEED WARNING If the above sequence is NOT displayed or the RED LED is on for any reason DO NOT PROCEED A...

Page 14: ...0 ohm range 15mA test current is low some RCD s may trip due to sensitivity or where there may already be additional leakage in the circuit being tested The Loop impedance in a TN system is small and therefore it is not recommended to test in the 2000 ohm range RCD s will have to be bridged to avoid tripping when using other test ranges Measured result may be influenced depending on the phase angl...

Page 15: ...range it may read 56 0A To hold the reading keep the button held down or turn clockwise to lock for Auto Test Normally PSC tests are conducted at point of origin e g distribution boards between phase and neutral When conducting PSC tests at socket outlets a test will be conducted between phase and earth due to the fixed wiring of the moulded mains plug WARNING This instrument is intended only for ...

Page 16: ...e following partial impedances Impedance of power transformer s secondary Phase conductor resistance from power transformer to fault location Protection conductor resistance from fault location to local earth system Resistance of local earth system R Resistance of power transformer s earth system Ro The figure below shows in marked line the Fault loop impedance for TT system Fig 6 For TN system th...

Page 17: ...hin 5 s When the protection device is a residual current device RCD Ia is the rated residual operating current I n For instance in a TT system protected by a RCD the max RA values are Note The loop tester models 4118A measure the fault loop impedance that is a value normally a little bit higher of RA But if the electrical installation is protected considering the loop impedance value also the RA f...

Page 18: ...e RCD tester model 5406A According to the international Standard IEC 60364 for TN system the following condition shall be fulfilled for each circuit Zs Uo Ia Where Zs is the Fault loop impedance Uo is the nominal voltage between phase to earth Ia is the current causing the automatic disconnection of the protective device within the time stated in table as follows Note For a distribution circuit a ...

Page 19: ...t be higher than Ia of the protective device concerned Practical example of verification of the protection in a TN system according to the international Standard IEC 60364 Fig 9 Rating A Disconnecting time 5s Ia A Zs Ω Ia A Zs Ω Disconnecting time 0 4s 6 10 16 20 25 32 40 50 63 80 100 28 46 65 85 110 150 190 250 320 425 580 8 2 5 3 6 2 7 2 1 1 53 1 21 0 92 0 71 0 54 0 39 47 82 110 147 183 275 320 ...

Page 20: ...tead of 400 V and phase to earth of 127 V instead of 230V and normally the neutral conductor is not used Connecting the loop testers to this system all three wiring check LEDs should be lit and the display reads a value of 127 V Only if all these conditions are respected the test can be carry out Fig 10 WARNING This instrument is intended only for use in single phase operation at 230V 10 15 AC pha...

Page 21: ...between L and N terminals Breaking current capacity of installed over current protection devices should be higher than Prospective Short Circuit current otherwise it is necessary to change the rated current of involved over current protection device Practical example of line impedance test and prospective short circuit current test The figure below shows in marked line the Line impedance phase to ...

Page 22: ...rument 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 If the overheat symbol appears in the display disconnect the instrument from the mains supply and allow to cool down When testing installation that has a large current capacity such as a power line be sure not to short live conductors with the tip of a probe Failur...

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Page 24: ...15 02 92 2233 DISTRIBUTOR Kyoritsu reserves the rights to change specifications or designs described in this manual without notice and without obligations ...

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