Megger LTW425 High Resolution Loop Tester


Megger approved distributor and service centre.

The Megger LTW425 series instruments offers a high resolution 2-wire loop testing solution that does not trip 30 mA RCDs and can be used on a wide range of voltages.

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Usually Stock or Short Lead Time

£ 464.10 rrp £ 595.00

save 22%

(£ 556.92 inc VAT.)

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The Megger LTW425 Loop Impedance Tester is three phase safe and category IV 300V rated, making it suitable for use on supplies from 50V to 300V AC single phase, as well as on 440V three phase installations. The LTW425 Tester automatically averages a large number of results over the duration of the test. This enables non trip testing to be performed without DC injection, a technique which is, in any case, proving ineffective with electronic RCDs.

The LTW425 offers a high current high resolution loop test to three decimal places. This is ideal for establishing the correct Ze on an incoming supply, especially on PME installations. Results of this test can also be used to calculate higher PFC results.


2 Wire Non-tripping loop tester.
50 V to 440 V operation.
110 V centre-tap loop testing.
CATIV installation testing.
AUTO start - operation.
0.01 Ω resolution.

Megger LTW425 Specifications:

  • 2 wire fast testing (high current).
  • Suitable for use on 110V to 280V applications.
  • Also suitable for use on 50V to 440V applications.
  • Phase to phase testing.
  • 20 KA PFC range.
  • Automatic noise detection and correction.
  • Auto loop test initiation.
  • Voltage and frequency measurements.
  • Max Zs display.
  • R1 + R2 display.
  • IP54 Weatherproof Case.
  • Power Supply: 8 x 1.5V Cells IEC LR6 Type (AA Alkaline).
  • Rechargeable: 8 x 1.2V NiCd or NIMH Cells.
  • Battery Life: 2000 consecutive tests.
  • Dimensions: 203 x 148 x 78mm.
  • Weight: 1000g ±10% excluding test leads.
  • Megger LTW 425 Warranty: 3 year.


Includes: Megger LTW425 Earth Loop Tester, BS1363 to 3 x 4mm Socket Leadset, 2 Wire Leadset with Croc Clips, Schuko Plug Test Lead - EU-SC, AU/NZ Plug Test Lead - EU-AU, Hard Carry Case and User CD.

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Megger LTW425 High Resolution Loop Tester