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AC/DC leakage current tester

GROUND FAULT DC CURRENT MEASUREMENT IN PV SYSTEM By Model 730

1. About DC Ground Fault Current in PV System

When the ground fault occurs at the DC current side of power conditioner, DC ground fault current will circulate from the earth to the DC current side of power conditioner via grounding line of boosting transformer & AC current side of power conditioner and then, through the inverter switching circuit. Consequently, DC ground fault current will be superposed to AC current and the current disparity will occur at P&N phase by the content of ground fault current.

2. About Detection of DC Ground Fault Current in Power Conditioner

ZCT built in DC current side of the internal power conditioner is monitoring current difference between P&N phase and power conditioner will stop, when the difference exceeds the limited value. Those limited values are different according to the power conditioner manufactures but they are generally 30mA~100mA.

3. About Measurement of DC Ground Fault Current by DC Current Clamp Tester

After making artificial ground fault (approx. 12mA), measurements of DC current at three places (grounding line of boosting transformer, DC current side of power conditioner and artificial ground fault point) were implemented by DC clamp tester (M-730). Consequently, the measured values of these three places were almost same, which means that all the DC ground fault current flowed out to AC current end and the current  difference of P&N phase at DC current side of power conditioner was almost same as DC ground fault current.

M-600

FEATURES

  • Wide application for process control and automotive service.
  • The world first AC/DC leakage current clamp tester with 0.1mA resolution.
  • The least influence from the external magnetic field and noise with double shielding CT.
  • Memory Function for MAX. and MIN. Value.
  • For measurements of 4〜20 mA current loop signal of transmission control

M-700

m700

FEATURES

  • The World First High Accurate AC/DC Leakage Current Testers.
  • High Sensitive for Low Range Leakage Current.
  • Suitable for Measurement of 4-20mA DC Controlled Circuit
  • DC mV Analog Signal Output.
  • Lowest Influence from Magnetization & Terrestrial Magnetism.
  • Wide Measuring Ranges – up to DC 1000mA & AC 10A.

M-730

m730

FEATURES

  • The World First High Accurate AC/DC Leakage Current Testers.
  • High Sensitive for Low Range Leakage Current.
  • Suitable for Measurement of 4-20mA DC Controlled Circuit
  • DC mV Analog Signal Output.
  • Lowest Influence from Magnetization & Terrestrial Magnetism.
  • Wide Measuring Ranges – up to DC 1000mA & AC 10A.

M-740

m740

FEATURES

  • The World First High Accurate AC/DC Leakage Current Testers.
  • High Sensitive for Low Range Leakage Current.
  • Suitable for Measurement of 4-20mA DC Controlled Circuit
  • DC mV Analog Signal Output.
  • Lowest Influence from Magnetization & Terrestrial Magnetism.
  • Wide Measuring Ranges – up to DC 1000mA & AC 10A.
Parameters M600 M700 M730 M740
Measuring function DC/AC Leakage Current (AC true RMS reading) (50/60Hz) AC/DC Leakage Current (45Hz~65Hz)
Range 200mA/2000mA/10A DC 100mA/1000mA,
AC 100mA/1000mA/10A (45Hz〜65Hz)
Resolution 0.1mA/1mA/0.01A 0.01mA/0.1mA/0.001A
Accuracy (23℃±5℃, 80%RH or less)
Range/Input range/Resolution/Accuracy
AC 200mA/0~1999mA/100μA/±1.0%rdg±5dgt (50/60Hz)
AC 2000mA/0~199.9mA/1mA/±1.0%rdg±5dgt (50/60Hz)
AC 10A/0~9.99mA/0.01A/±1.0%rdg±10dgt (50/60Hz)
DC 200mA/0~199.9mA/100μA/±1.0%rdg±3dgt
DC 2000mA/0~1999mA/1mA/±1.0%rdg±3dgt
DC 10A/0~9.99mA/0.01A/±1.0%rdg±10dgt
Error by hysteresis of hall effect :±3%rdg
DC Current
(Accuracy:23℃±5℃, less than 85%RH)
Range/Measuring Range/Resolution/Accuracy
100mA/0.1~±50.00mA/0.01mA/±1%rdg±5dgt
100mA/±50.01~±99.99mA/0.01mA/±1%rdg±10dgt
1000mA/1~±300mA/0.1mA/±1%rdg±10dgt
1000mA/±300.1~±700mA/0.1mA/±2%rdg±10dgt
1000mA/±700.1~±999.9mA/0.1mA/±3%rdg±10dgt

AC Current
(Accuracy:23℃±5℃, less than 85%RH)
Range/Measuring Range/Resolution/Accuracy
100mA/0~99.99mA/0.01mA/±1%rdg±10dgt(50/60Hz)
1000mA/0~999.9mA/0.1mA/±1%rdg±10dgt(50/60Hz)
10A/0~9.999A/0.001A/±1%rdg±10dgt(50/60Hz)
Max. input current : AC 20A
Display 3.5 digit LCD, max. reading of 1999 Max. 2000 count on LCD with annunciator
Jaw opening capability 20㎜φ 5㎜φ (CTP-05DC) 30㎜φ (CTP-30DC) 40㎜φ (CTP-40DC)
Safety standard IEC 61010-1, IEC 61010-2-032 CATⅡ 300V. IEC61010-1/61010-2-032 CATⅡ 600V or CATⅢ 300V
Measuring method Dual integration method with true RMS reading. Clamp CT (CTP-05DC:Slide/Hook Type)
AC current detection : Average sensing
A/D conversion : Dual integration method
Sampling 1.6 times/s 1 time/sec. for DC and 6 times/sec. for AC
Over range indication ”OL” mark on LCD
Data hold indication ”DH” mark on LCD
Low battery indication ”B” mark on LCD
Min. memory function "Min" mark on LCD with min. value -
Max. memory function "Max" mark on LCD with max. value -
DC current zero offset By push button switch "0 ADJ" switch
Limitation of circuit voltage Less than AC/DC 300V less than AC/DC 500V
Withstanding voltage AC 2300V/1 minute max. between the core of CT and outer case. AC 3700V/1 minute between CT and outer case
Operating temperature 0℃〜50℃, < 80% RH (Non-condensing) 0〜50℃, < 85%RH (without condensation)
Storage temperature -20℃〜60℃, < 75% RH (Non-condensing) -10〜60℃, < 70%RH (without condensation)
Power supply 1.5V (“AA” size, UM-3)×2 1.5V ("AAA" size, UM-4)×4
Battery life 120 hours or more (Alkalin) Approx. 200h for continuous use
Auto power off The meter is set to power off mode approx. 10 minutes after the power switch on. Approx. 10 minutes after power on and (Auto power off function can be released by the switch)
Size 76(W)×194(H)×30(D)㎜ Display Part 78(W)×155(H)×32(D)㎜
CT (CTP-05DC) 19(W)×133(H)×28(D)㎜
Display Part 78(W)×155(H)×32(D)㎜
CT (CTP-30DC) 33(W)×170(H)×24(D)㎜
Display Part 78(W)×155(H)×32(D)㎜
CT (CTP-40DC) 64(W)×162(H)×23(D)㎜
Weight Approx. 340g Display: approx. 280g
CT : approx. 100g
Display: approx. 280g
CT : approx. 165g
Display: approx. 280g
CT : approx. 130g
Accessories Carrying case .................. 1
Instruction manual............ 1
Batteries .......................... 2
Carrying case .................. 1
Instruction manual............ 1
Batteries .......................... 4
Signal Output DC 100mV full scale to each range
(output impedance: less than 10KΩ)