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Megger LTW425

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The Megger LTW425 two wire earth loop tester verifies the loop impedance of a live electrical circuit, ie without the need to disconnect the electrical supply. The instrument also offers a 2 wire loop testing solution that does not trip 30 mA RCD's and can be used on a wide range of voltages.

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  • 2 Wire Non-tripping loop tester
  • 50 V to 440 V operation
  • 110 V centre-tap loop testing
  • Backlight display
  • CATIV installation testing
  • AUTO start - operation
  • High resolution (0.001Ω) 2 wire testing + maxZ + (R1+R2)


Voltage measurement

AC 50V to 440V

Voltage accuracy ±2% ±1V

Voltage range 25Hz to 99.99Hz

Voltage accuracy ±0.1Hz

No-trip loop and high current loop test

Source voltage 50V to 440V (50Hz)

Display range 0.01Ω to 2000Ω

Accuracy ±5% ±0.03Ω

Nominal test current No-Trip loop test 15 mA (at nominal 230Vac supply) High current loop test 4 A (at nominal 230 Vac supply)

Operational range 0.30Ω to 1000Ω

High resolution loop test

Source voltage 50 V to 440 V (50Hz)

Display range 0.001Ω to 2000Ω

Accuracy ±5% ±0.01Ω

Nominal test current 4A at nominal 230V supply

Operational range 0.30Ω to 1000Ω

Prospective Fault Current (PFC)

Prospective fault current Measured Source Voltage / Loop resistance

Maximum range 40 kA; accuracy is derived from loop test and voltage measurement.

Battery life 2000 consecutive tests

Weight 1kg approximately excluding test leads

Dimensions 203 x 148 x 78 mm



Megger LTW300 series data sheet

  • Technical Document
  • PDF file
  • 319 KB

Megger LTW300 series user manual

  • Technical Document
  • PDF file
  • 2 MB
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