Megger VLF Sinus 45 kV Cable Test & Diagnosis System
The Megger VLF Sinus 45 is a portable VLF (very low frequency) sine wave cable test and diagnosis system rated to 45 kV, used by utilities, electrical engineers, and cable contractors in Ireland for the withstand testing and condition assessment of MV cables. It is the test system you reach for when DC testing is no longer appropriate and you need a true sine wave at low frequency to stress polymeric insulation safely in the field.
Modern XLPE cable does not respond well to DC test voltage. A VLF sine wave 45 kV cable tester applies an AC stress at typically 0.1 Hz, close enough to mains-frequency behaviour to be representative, but at a low enough frequency to keep the test set portable. That is why VLF and DC testing are now treated as different jobs, and why VLF has become the standard for new and in-service medium-voltage cable testing.
What you can test with the VLF Sinus 45
- VLF withstand (proof) testing: pass or fail integrity check on commissioning, post-repair, and periodic cable testing.
- Sheath testing: verify outer sheath integrity and locate sheath faults using DC modes that the system supports.
- Tan Delta measurement: dissipation factor as a trendable indicator of insulation ageing, moisture ingress, and defects across the cable length.
- Partial discharge (PD) diagnostics: with the appropriate accessory configuration, localise PD activity at joints, terminations, and along the cable.
- Sheath fault pinpointing as part of a wider fault location workflow.
The combined withstand-plus-diagnosis workflow is what makes the system more than just a 45 kV tester. You proof-test the cable to confirm it holds, then use Tan Delta and PD to grade its condition rather than just pass it.
Key features
- VLF sine wave output for representative AC stress at 0.1 Hz, suitable for XLPE and other polymeric MV cable.
- 45 kV peak test voltage covering common European and Irish MV network classes.
- High test capacity for testing of long cable runs at reduced frequency on larger network sections.
- Compact system design built for field deployment in substations, switchrooms, and on-site cable terminations.
- Measurement accuracy from a stable VLF sine output and a precision measurement chain, giving repeatable Tan Delta and PD trending across return visits.
- Documented test data output for handover, asset records, and condition-based maintenance reporting.
Specifications: what to confirm before you order
| Specification | What to confirm |
| Test voltage | Peak output up to 45 kV, AC sine and DC modes as required |
| Test frequency | VLF range, typically 0.1 Hz, with reduced frequency for long cable runs |
| Cable length / capacitance | Confirm the test capacity is matched to your longest planned cable run |
| Diagnostic options | Tan Delta and PD modules included or available as accessories |
| Power supply | Mains and field-supply options for substation and remote site use |
| Calibration | Supplied calibrated; periodic recalibration through Powerpoint’s lab |
Target users and applications
The Megger VLF Sinus 45 is specified by:
- Utilities and DNOs for planned outage testing, asset health assessment, and acceptance of new cable installations
- Electrical engineers and maintenance teams in substations, switchgear environments, and large industrial sites
- Cable installation and commissioning contractors for post-repair verification and documented handover testing
- Renewable power operators on wind and solar balance-of-plant MV cabling and collection networks
It complements rather than replaces lower-class cable testers and dedicated sheath testing kit; choose the VLF Sinus 45 when you need both withstand and diagnostic capability in a single test system at MV.
As authorised Megger distributor in Ireland, Powerpoint Engineering supports the system with in-house calibration and repair, accessory supply, and operator training for cable test and diagnosis work.
FAQs
Why use VLF instead of DC for testing modern MV cable?
DC testing can stress modern XLPE insulation in ways that mask defects or even cause damage to the cable. VLF sine wave at 0.1 Hz applies an AC stress that mirrors service conditions far more closely, while still keeping the test set portable. For polymeric MV cable, VLF is now the recommended approach.
Can the Megger VLF Sinus 45 do partial discharge testing?
Yes, with the appropriate PD module and accessories the system supports VLF-based partial discharge diagnostics, allowing you to localise PD activity at joints and terminations rather than blanket-replace cable on age alone.
How long a cable run can the VLF Sinus 45 handle?
It depends on cable capacitance and the test frequency you select. Long runs can be tested at reduced frequency. Send us your cable type, cross-section, and route length and we will confirm that the test capacity covers your worst case before you order.
To match the right Megger VLF Sinus 45 configuration to your network and diagnostic needs, request a quote or speak to our team for compatibility advice.
Megger VLF Sinus 45 kV - Test and Diagnosis System Datasheet
For additional technical details about the Megger VLF Sinus 45 kV - Test and Diagnosis System please refer to the product datasheet.
