Megger LTW425 Earth Loop Tester
Megger's LTW425 is the best model available in Megger's LTW range of earth loop testers. It includes all of the features found on the other models and also enhances the overall resolution of the instrument, bumping it up from 0.001 to 0.0001Ω resolution. It's also the only model in the series to feature 40 KA PFC range.
Like other models in the series this earth loop tester is capable of performing 2, 3 and 4 wire earth loop measurements. It also performs 2-wire fast testing (high current) which can be used when an RCD isn't present in the installation.
The LTW425 also automatically compensates for excess noise present within the installation, ensuring that the accuracy of loop tests performed remains high. The instrument is fully suitable for use on 110 to 280V and 50 to 440V applications, can carry out phase to phase testing, automatically starts loop tests when test leads are connected and can also be used to get accurate measurements of both frequency and voltage. It also displays Max Zs and R1 + R2.
There are four separate models available in Megger's LTW300 range of earth loop testers. The following table outlines the difference between each of these instruments:
| Function | LTW315 | LTW325 | LTW335 | LTW425 |
| 2-Wire Non Tripping Loop Testing | √ | √ | √ | √ |
| 2-Wire Fast Test (High Current) | √ | √ | √ | √ |
| 110V to 280V Applications | √ | √ | √ | √ |
| 50V to 440V Applications | - | √ | √ | √ |
| Phase to Phase Testing | - | √ | √ | √ |
| 20KA PFC Range | √ | √ | √ | √ |
| 40KA PFC Range | - | - | - | √ |
| 0.01Ω Resolution | √ | √ | √ | √ |
| 0.001Ω Resolution | - | - | - | √ |
| AUTO Noise Detection | √ | √ | √ | √ |
| AUTO Start Loop Test | √ | √ | √ | √ |
| Voltage Measurements | √ | √ | √ | √ |
| Frequency Measurements | √ | √ | √ | √ |
| Max Zs Display | - | √ | √ | √ |
| R2+R2 Display | - | √ | √ | √ |
| Backlit Display (White Light) | √ | √ | √ | √ |
| Built-In Front Cover (Foldaway) | √ | √ | √ | √ |
| IP54 Weatherproof Case | √ | √ | √ | √ |
| Accepts Rechargeable Batteries | √ | √ | √ | √ |
| Test Result Storage | - | - | √ | - |
| Downloadable | √ | √ | - | √ |
Megger LTW425 Earth Loop Tester Key Features
- 2-wire non trip loop testing
- 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
- 0.01Ω resolution
- Automatic noise detection and correction
- Auto loop test initiation
- Voltage and frequency measurements
- Max Zs display
- R1 + R2 display
Full List of Products Included
- 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
- User CD
Accessories
Please find below a selection of accessories available for the Megger LTW425 Earth Loop Tester. For further information, or to add an item listed below to an order, please contact our sales team.
| Our SKU | Megger's Part Number | Product |
| 1001-977 | 1001-977B | Fused 10A test lead set (Red/Green) with Prods and clips right angle plugs F10A 50kA (Boxed) |
| 6220-810 | 1004-323B | SIA10 Socket Interface Adaptor UK to 3 Leads x 4mm (Boxed) |
| 1001-976 | 1003-132B | Unfused Lead Set Red, Green (Boxed) |
| 1007-167 | 1007-167 | Blow Moulded Case MIT/LT/RCDT 300 Series |
Megger LTW425 Technical Specifications
| General Accuracy | |
| All accuracy statements are based on: | |
| Ambient Temperature | 23° ±2°C |
| Nominal Voltage Source | 230V a.c ±1% |
| Voltage Measurements | |
| (ac only) | 50V to 440V |
| Accuracy | ±2% ±1V |
| Frequency Measurements | |
| Range | 25Hz to 99.99Hz |
| Accuracy | ±0.1Hz |
| A warning will be shown if applied voltage exceeds 440V. Damage will occur if applied voltage exceeds 600V rms |
|
| Loop Testing Accuracy | |
| ±5% ±0.03Ω | @230V a.c |
| ±10% ±0.02Ω | |
| ±15%±0.03Ω | @50V a.c. |
| No Trip Loop and High Current Loop Test | |
| Source Voltage | 50V to 440V (49Hz to 50.1Hz) |
| Display Range | 0.01 to 2000Ω |
| Accuracy | ±5% ± 0.03Ω |
| No Trip Loop Test Nominal Current | 15ma (at nominal 230V a.c supply) |
| High Current Loop Test | 4A (at nominal 230V a.c supply) |
| Operational Range | 0.30 to 1000Ω |
| Prospective Fault Current (PFC) | |
| Prospective Fault Current | =Measured Source Voltage/Loop Resistance |
| Maximum Range | No Trip Mode: 20KA |
| Accuracy is derived from loop test and voltage measurement | |
| Safety |
IEC 61010 |
| EN61557 |
Complies with the following parts of EN61577: |
| E.M.C | In accordance with IEC61326-1 |
| Power Supply | |
| Battery | 8 x 1.5V Cells IEC LR6 Type (AA Alkaline) |
| Rechargeable | 8 x 1.2V NiCd or NIMH Cells |
| Battery Life | 2000 consecutive tests |
| Mechanical | |
| Weight | 1000g ±10% excluding test leads |
| Dimensions | 203 x 148 x 78mm |
| SKU | MEGLTW425 |
|---|---|
| Manufacturer Part Code | LTW425-EU-BS |
| Model Ref | LTW425 |
| Country of Origin | United Kingdom |
