Megger LTW425-EU-BS Loop Impedance & RCD Combined Tester, Loop Impedance Test Type 2 Wire 440V

  • RS Stock No. 198-441
  • Mfr. Part No. LTW425-EU-BS
  • Brand Megger
Technical Reference
Legislation and Compliance
RoHS Status: Not Applicable
COO (Country of Origin): GB
Product Details


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. 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.

High resolution (0.001Ω) 2 wire testing + maxZ + (R1+R2)
Backlit display
2 wire loop tests: Phase to Earth, Phase to Neutral or Phase to Phase
3 phase circuits with RCD protection can be tested
Tests radial circuits where the circuit does not return to the origin, even where only a phase and neutral contacts are available.
10 second non trip loop test time with Auto test extension up to a further 10 seconds if noise is detected, to improve the accuracy of the test
High current loop testing for supplies that do not have an RCD fitted
AUTO START will start the loop test running as soon as the test leads are connected; No need to press the test button means much safer testing
PFC Display up to 40kA
Voltage and frequency measurement
110 Vac systems including 110V centre tap to earth (55 V phase to earth) can be tested on the secondary winding.
IP54 Weatherproof case
Optional 10A fused 2 wired test leads and crocodile clip set
Complies with IEC61010-1 300V CATIV safety standard and meets EN61557


RS is an authorised Megger distributor. Purchased though RS this product is eligible for the Megger extended 3 Year warranty

Supplied with

Test lead set with crocodile clips, mains socket test lead, 8 AA alkaline batteries, hard carry case and instructions.

Attribute Value
Loop Impedance Test Type 2 Wire
Maximum Voltage Measurement 440V
RCD Test Type AC Selective
Best Loop Test Accuracy ±10%
RCD Test Current 4A
Non-Trip Loop Test Yes
Safety Category CAT IV 300 V, IEC 61010
Display Type LCD
Battery Life 2000 Tests
Battery Type AA
Power Source Battery
Dimensions 203 x 148 x 78mm
Weight 1kg
Model Number p LTW425
Minimum Operating Temperature -10°C
Height 78mm
Width 148mm
Maximum Operating Temperature +50°C
Safety Category Level CAT IV
Safety Category Voltage 300V
Length 203mm
2 In stock - FREE next working day delivery available
Price Each
£ 595.00
(exc. VAT)
£ 714.00
(inc. VAT)
Per unit
1 +
Calibration Options:
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