Megger STX40 Portable Standalone Cable Fault Location Unit

The STX 40 is one of the most powerful and convenient portable fault location units available, combining single rotary knob or touchscreen control with fully automated, motorised high-voltage switches. Designed for all key fault location tasks, such as analysis, prelocation, and pinpointing, it is ideal for low and medium voltage XLPE or EPR insulated cables. With a 40 kV DC source and a high-frequency burner, it also excels on PILC cables.

Lightweight and highly mobile, the STX 40 features a rainproof outdoor design (IP43 rated) with large pneumatic tyres, an adjustable handlebar, and an optimised centre of gravity for all-terrain use. Its bright, sunlight-readable 10.1” colour display and software-controlled automatic mode selection ensure simple, efficient operation. Testing capabilities include insulation testing up to 20 kV and 650 MΩ, DC hipot testing up to 40 kV with automatic breakdown detection, and integrated Radar/TDR plus ARM, ICE, and DECAY prelocation methods. Surging (thumping) is available at 8/16/32 kV with 2000J energy output, with an optional 4 kV stage delivering 1,100J. The built-in high-frequency burn mode provides up to 40 kV DC and 850 mA for superior fault conversion compared to traditional burn-down units.

The STX 40 incorporates a comprehensive suite of fault-finding technologies. Inductive ARM Best Picture Multishot overlays 32 high-voltage fault traces with a reference trace and automatically displays the clearest result, offering excellent arc ignition and stability via inductive filtering. ICE/Surge Pulse measures the current component of the travelling wave, ideal for long cables, PILC cables, and wet or non-chargeable faults. DECAY captures the voltage component, making it suitable for long or high-voltage transmission cables and high-resistance faults. The IFL (Intermittent Fault Location) mode continuously captures radar traces to detect unstable or changing faults, which is particularly useful for street lighting and other LV applications.

The STX 40 offers a modular design that allows easy integration into exisiting test systems or vans and supports remote operation via a USB interface. Test results and traces can be stored internally or exported for documentation and analysis. Its self-diagnostic system monitors all key components, ensuring reliability, and reducing maintenance needs. The unit operates from standard mains power or an integrated battery, providing flexibility for field use. Built with durable, weather-resistant materials, the STX 40 delivers consistent performance in demanding environments while maintaining operator safety through automatic grounding and interlock protection systems.

To arrange a demo for this product, simply click the ‘Arrange a Demo’ button at the top of the page, and to find out more about this product and the options that are available, do not hesitate to contact our team.

Megger part number: STX40

Key Features

• Powerful portable fault location unit with single rotary knob or touchscreen control and automated motorised HV switches
• Comprehensive fault location capabilities including analysis, prelocation, and pinpointing for low and medium voltage XLPE, EPR, and PILC cables
• 40 kV DC source and high-frequency burner for effective fault conversion and testing versatility
• Rugged, mobile outdoor design (IP43 rated) with large pneumatic tyres, adjustable handlebar, and optimised centre of gravity for all-terrain use
• Bright 10.1” sunlight-readable colour display with software-controlled automatic mode selection for ease of operation
• Insulation testing up to 20 kV / 650MΩ and DC hipot testing up to 40 kV with automatic breakdown detection and ramp function
• Integrated Radar/TDR, ARM, ICE, and DECAY prelocation methods for precise fault analysis
• Surge (thump) testing at 8/16/32 kV with 2000J output, optional 4 kV stage (1100 J)
• High-frequency burn mode up to 40 kV DC / 850 mA for superior performance on difficult tasks
• Inductive ARM Best Picture Multishot automatically identifies the clearest fault trace for accurate results
• ICE, DECAY, and IFL modes for locating long-cable, wet, high-resistance, or intermittent faults
• Modular, integration-ready design suitable for system or van installation with USB remote operation
• Internal storage and data export for easy documentation and reporting
• Self-diagnostic system for reliability and reduced maintenance
• Dual-power operation via mains supply or internal battery for flexible field use
• Saftey-focused design with automatic grounding, interlock protection, and weather-resistant construction