Understanding earth leakage: Why testing matters more than ever

In this article, learn what earth leakage is, why it matters, and how Kewtech testing equipment helps identify faults, improve safety, and prevent nuisance tripping. Earth leakage testing has become an increasingly critical part of modern electrical verification and maintenance, particularly as installations age and the cumulative effects of leakage currents become more pronounced. With the widespread use of RCDs and RCBOs providing life-saving protection, understanding, identifying, and managing earth leakage is essential to ensure both safety and reliability. What is earth leakage? Earth leakage refers to the unintended flow of electrical current from a circuit to earth. This can occur due to insulation breakdown, damaged conductors, moisture ingress, or faulty equipment. Even in healthy installations, small amounts of leakage are inevitable due to the design of modern electrical equipment. However, while these currents are typically harmless in isolation, their cumulative effect across multiple circuits can create significant issues. RCBOs and nuisance tripping RCBOs and RCDs are designed to detect imbalances between live and neutral conductors and disconnect the supply rapidly, often within milliseconds, when leakage exceeds a set threshold, typically 30mA in domestic settings. This function is crucial in preventing electric shock and reducing the risk of fire. However, these are not selective devices; they respond to total leakage on the circuits they protect. As a result, they can be susceptible to “nuisance tripping” when leakage currents approach their operating threshold without an actual fault being present. An increasing challenge with modern installations This challenge is becoming more common due to two key factors: ageing circuits and the rise of modern electronic loads. Over time, cable insulation degrades, becoming brittle, cracked, or moisture-affected, all of which create pathways for leakage current. These faults are often hidden within walls or under floors, making them difficult to detect without proper testing. In parallel, modern installations now include devices such as LED drivers, EV chargers, electric showers, air-conditioning, and switch-mode power supplies, all of which contribute small but continuous leakage currents. Individually, these leakage currents may only amount to a few milliamps, but when combined across several circuits, particularly on split-load consumer units, they can approach or exceed the protective device’s trip threshold. Cumulative leakage from cable capacitance, appliances, and transient events can easily reach 10–18 mA on a 30mA RCBO or RCD, leaving very little headroom before unwanted tripping occurs. This is especially problematic in older installations where insulation resistance has already declined. The dangers The danger here is twofold. Firstly, nuisance tripping can lead to inconvenience, loss of power, and potential damage to equipment. More critically, it may mask genuine faults or lead to complacency, where users repeatedly reset protective devices without investigating the underlying issue. Secondly, ageing or inappropriate RCDs and RCBOs may fail to operate correctly under certain conditions, either tripping too easily or, more concerningly, failing to trip when required. The solution This is where effective earth leakage testing becomes invaluable. Using an earth leakage clamp meter, such as the KEWTECH KEW2434, allows you to measure leakage currents quickly and non-intrusively. This can be achieved by measuring the leakage on the earthing conductors, or by measuring the unbalanced load on the live and neutral conductors simultaneously. This enables the identification of circuits with elevated leakage without the need to disconnect conductors or disrupt the installation. Testing with a clamp meter provides several advantages. It allows for the assessment of total leakage at the origin, followed by the isolation of individual circuits to pinpoint contributors. It also helps differentiate between acceptable “background” leakage and abnormal levels indicating faults. This is particularly important in modern installations where some leakage is unavoidable, and the goal is to manage it rather than eliminate it entirely. Furthermore, with the vast array of tripping characteristics and types of RCB/RCBO now recommended for various applications; appropriate selection is critical and ‘nuisance tripping’ can be a factor, which is why proper measurements should be taken prior to selection. The takeaway As electrical systems continue to age and the number of leakage-producing devices increases, proactive earth leakage testing is no longer optional but is essential. RCDs/RCBOs remain a cornerstone of electrical safety, but their effectiveness depends on the condition of the installation and the level of leakage present. By incorporating tools such as an earth leakage clamp meter into routine testing, electricians can identify issues early, reduce nuisance tripping, and ensure that protective devices operate as intended, ultimately safeguarding both property and lives. For more from Kewtech, click here.

KNIPEX unveils new tool case for photovoltaics

Hand tools manufacturer KNIPEX has introduced a new tool case for photovoltaic (PV) installations, bringing together a selection of tools designed for working with MC4 and MC4 Evo 2 connectors. The KNIPEX Tool Case for Photovoltaics is intended to provide electricians with the equipment needed for the installation and maintenance of solar systems, with all tools housed in a single, impact-resistant case. At the centre of the kit are the Crimp System Pliers, designed for plug-type connectors used in photovoltaic installations and suitable for cables up to 10mm². The factory-calibrated crimping pressure, together with a pre-installed crimping die and locator, is intended to provide consistent crimps. An additional locator extends compatibility across the MC4 connector series. A selection for photovoltaic installations The case also includes cable shears for cutting copper cables up to 15mm in diameter, along with a Precision Insulation Stripper featuring blades designed for 4.0mm², 6.0mm², and 10.0mm² cable cross-sections commonly used in photovoltaic applications. Also included is the KNIPEX Mounting Tool Set, comprising two assembly tools for tightening housing screw connections and unlocking MC4 and MC4 Evo 2 connectors. The tools feature an integrated magnetic coupling to keep them together during transport, whilst a built-in millimetre scale allows installers to check stripped cable lengths. The Crimp System Pliers are compatible with crimping dies and locators across the KNIPEX 97 49 range, allowing the system to be used for a wider variety of crimping applications. The impact-resistant case features a precision-cut foam insert, with dedicated storage for the supplied tools, additional crimping dies, and locators. For more from KNIPEX, click here.

Knightsbridge launches Helix commercial lighting range

Knightsbridge, a UK manufacturer of wiring accessories and lighting, has expanded its commercial lighting portfolio with the launch of Helix, a modular, non-corrosive lighting range designed for commercial and industrial environments. Developed as an evolution of the company's Torlan range, Helix is suitable for both indoor and outdoor installations. The range comprises three product variants - Helix One, Helix Shift, and Helix Max - offering different levels of functionality while sharing a common modular design intended to simplify installation and maintenance. All Helix fittings are manufactured from anti-corrosive polycarbonate and feature stainless steel clips as standard. Each fitting is rated IP66 and IK10 for protection against dust, water ingress, and impact. Installation features include rear, side, and end conduit entries, detachable terminal blocks, large bracket fixing points, and compatibility with BESA box mounting. Three variants for different applications Helix One is the entry-level option, offering fixed wattage outputs and a 4000K colour temperature. Available in 2ft, 4ft, 5ft, and 6ft versions, the range includes both 230V models and selected 110V variants supplied with a 1m flex and an IP65 junction box. It also supports plug-and-play emergency and microwave sensor modules. Helix Shift adds quad-wattage adjustment and selectable 3000K, 4000K, and 5700K colour temperatures. Available in outputs ranging from 13W to 60W, it also supports plug-and-play emergency and microwave sensor modules. Helix Max is supplied with an integrated corridor sensor offering three-step dimming, alongside quad-wattage adjustment and tri-CCT selection. The range supports optional emergency modules and is available in 4ft, 5ft, and 6ft formats. The Helix range is compatible with accessories used across Knightsbridge's batten and Preceptor linear ranges, allowing installers to use common components across multiple lighting installations. For more from Knightsbridge, click here.

Prevent hazards with the KT1700 single pole tester

In recent years, there has been increasing concern in the industry regarding PEN faults, a specific type of network fault with potentially lethal consequences. Whilst the rise in PEN faults is being acknowledged and investigated, it’s important to note that these are not the only way that hazardous situations - including touch voltage and diverted current flow - are created. In particular, there has been an increasing number of incidents where engineers have come into contact with live metallic parts (e.g. metal casings or equipment) during installation or maintenance activities. These contacts can and have led to fatalities. Touch voltages and diverted currents Touch voltages: This occurs when there is a fault in the system that results in no return path for current (i.e. due to a broken or disconnected earth or neutral, combined with other faulty wiring). As a result, metallic parts (such as a distribution board, boilers, or control panel) that are connected to the electrical earth could be raised to a dangerous potential. Diverted current: This is a more complex fault, where the current may flow through unintended paths (e.g. through earth or neutral conductors). Even though the circuit might appear to be functioning normally, diverted current can present serious dangers. Issues with current safe isolation procedures The current safe isolation procedures in place often do not specifically account for or test for touch voltages and diverted current. Even though the best industry practices for safe isolation and proving dead are followed, these two specific hazards are often overlooked. The proving dead process usually involves opening enclosures or testing electrical terminals to confirm that the equipment is not live. However, this step can be potentially lethal if there is already a touch voltage present. Test before touch: The missing step The concept of ‘Test Before Touch’ is well established and often taught to engineers. However, it’s usually focused on high-voltage equipment and not before entering or touching low-voltage equipment like distribution boards, control panels, pipework, and appliance casings (e.g. boilers or motor casings). In practice, engineers may not always adhere to this guideline, especially when handling parts of the installation that seem to be disconnected or 'dead'; they may neglect to check if there is a touch voltage or diverted current present. The KT1700 for hazard detection When it comes to electrical safety, you should not be guessing. The KT1700 single pole contact voltage tester from Kewtech is your first line of defence against hidden electrical hazards on metalwork and equipment. Make direct contact with metal enclosures, distribution boards, earth bonding, and pipework before you go near them and get a clear, instant warning if hazardous voltages are present. That’s real peace of mind before you touch. Unlike non-contact voltage testers, the KT1700 contact voltage tester delivers reliable voltage and live phase detection, helping you identify increasing network hazards such as PEN faults, diverted neutrals, phenolic breakdown, and touch voltages early. [embed]https://www.youtube.com/watch?v=WtHnELZhRuw[/embed] For more from Kewtech, click here.

Greenwich subway lighting upgraded with Acrospire LED system

British LED lighting manufacturer Acrospire has completed an LED lighting upgrade across 12 pedestrian subways in the Royal Borough of Greenwich, improving visibility and supporting safer public spaces. Delivered in partnership with Greenwich Council and contractor FM Conway, the project replaced ageing lighting installations that had resulted in inconsistent illumination and reduced visibility. The scheme was supported by funding from the Mayor's Energy Efficiency Fund (MEEF). Acrospire carried out lighting surveys and designed bespoke schemes for each location using its VandaWay lighting system. Instead of traditional ceiling-mounted luminaires, the fittings were installed along the upper edges of subway walls and, where appropriate, on railings. The company says this provides more consistent illumination across both walls and walkways, improving visibility while reducing shadowed areas. The lighting designs also accounted for changes between daylight and night-time conditions, with illumination levels tailored to support visibility when entering and leaving each subway. Lighting design tailored to each location According to Acrospire, Bryan Close Subway achieved daytime illuminance levels of more than 300 lux, while night-time lighting was reduced to minimise glare without affecting visibility. At Waterlily Walk, where the subway runs alongside a waterway, the lighting was designed to minimise light spill into the surrounding environment. Ranjit Reehal, Area Sales Manager at Acrospire, comments, "Subways present a unique challenge. It’s not just about lighting the space; it’s about how people feel moving through it. "By improving visibility and removing dark spots, you create an environment where people can see clearly ahead of them, and that has a real impact on confidence and safety." The installation uses vandal-resistant luminaires designed for public environments, with the aim of reducing maintenance requirements and improving long-term reliability. Alongside improving visibility, the move to LED lighting is expected to reduce energy consumption and support the council's wider carbon reduction objectives. For more from Acrospire, click here.

Smart HVAC: From reactive to intelligent

In this exclusive article for ECN, Sadiq Sayed, SVP Digital Energy Software Business at Schneider Electric, explores how AI-powered HVAC optimisation is transforming commercial buildings from reactive, fixed systems into intelligent, self-tuning assets that cut energy waste and improve performance: Commercial buildings rely on HVAC to keep occupants comfortable and air quality on spec. For electrical contractors, the pressure point is delivery: tighter energy targets, tougher compliance expectations, and more variable loads mean clients want upgrades that can be installed cleanly, commissioned faster, and proven in operation, without ripping and replacing whole systems. That’s where data‑driven HVAC optimisation comes in. Using existing BMS signals, added metering and sensors where needed, plus analytics/AI and digital twins, contractors can help shift sites from fixed schedules and reactive call‑outs to continuous, predictive performance. Done well, it cuts energy and carbon, flags faults earlier, improves uptime, and reduces repeat visits - all while keeping comfort steady. A new generation of intelligent HVAC systems Traditional approaches to HVAC management are no longer enough. Most commercial buildings still operate on fixed schedules and static setpoints, with little consideration for real-time occupancy, weather fluctuations, or equipment health. Over 30% of HVAC consumption is estimated to be unnecessary, resulting in wasted energy and missed opportunities for optimisation. At the same time, facility teams are being asked to do more with less. The building technology skills gap is widening, regulations are tightening, and there is an increased need for more flexible spaces in line with changing business needs. In this context, AI-powered HVAC optimisation is not just a technological upgrade; it’s non-negotiable. AI optimisation for HVAC systems AI brings a new level of intelligence to HVAC operations. By continuously analysing data from sensors, weather feeds, occupancy patterns, and asset health, AI algorithms can predict and adjust system behaviour in real time. They learn the unique rhythms of each building, predicting demand and proactively adjusting setpoints, ventilation rates, and equipment operation. Over time, the AI engine refines its models, learning from every data point to optimise performance. This optimising shift from reactive to adaptive is transformative; buildings become living systems, continuously tuning themselves for efficiency, comfort, and resilience, without constant human oversight. The technology foundation for AI-powered HVAC optimisation AI-powered HVAC optimisation is built on a comprehensive technology stack. At the core are building management systems (BMS), which serve as the nerve centre, aggregating data from HVAC equipment, sensors, smart meters, and other building systems. This foundation enables centralised control and monitoring and is essential for AI integration. Digital twins, or virtual replicas of buildings, are continuously updated with real-world data. AI models simulate HVAC operations within the digital twin, allowing facility managers to test scenarios, predict outcomes, and identify optimal parameters, without impacting actual operations. Digital twins are invaluable for risk-free experimentation and long-term planning. Real-time data integration is another critical component. AI engines ingest data from a wide range of sources, and this continuous data flow enables real-time decision-making, fault detection, and predictive maintenance. Hybrid architectures that combine the strengths of cloud and edge computing are becoming more common. Cloud AI handles large-scale data aggregation and complex analytics, while edge AI delivers real-time responsiveness at the device level. This balance ensures both portfolio-wide optimisation and immediate, local control. Finally, intuitive dashboards and mobile apps empower facility teams with actionable insights, alerts, and performance metrics. Automated work orders, fault diagnostics, and energy analytics streamline operations and simplify maintenance, making advanced HVAC management accessible to teams of all sizes. The path to AI-driven HVAC optimisation The first step is a site audit: what plant is in place, what controls strategy is being used, how is the BMS set up, and where might the electrical infrastructure limit performance (switchgear capacity, harmonics, power quality, protection, and resilience requirements). A structured survey of HVAC assets, energy use, and operating constraints helps pinpoint where controls upgrades, metering, and integration will deliver the quickest wins. Next comes the data layer. AI only performs as well as the signals you feed it, so it’s about getting the basics right: reliable sensor inputs, sub‑metering where it’s missing, consistent naming/tagging, time sync, and clear comms paths from field devices to the BMS/SCADA. For contractors, this is often the make-or-break scope because it’s the part that determines whether optimisation is actually measurable and maintainable. Platform selection matters too. Look for solutions that work with open protocols (e.g. BACnet/Modbus), support hybrid edge/cloud deployment, and can scale from one building to an estate without locking the client into a single vendor or forcing a controls rip-out. Deployment should be treated like a commissioning project, not an “IT install”. Integration, functional testing, alarm rationalisation, and trend verification are essential, alongside practical handover so on-site teams can use the dashboards and act on recommendations. Finally, optimisation is iterative. Ongoing monitoring, periodic recommissioning, and parameter tuning keep performance on track as seasons, occupancy, and equipment condition change - turning the initial upgrade into sustained energy, carbon, and reliability gains. For more from Schneider Electric, click here.

Registrations now open for Screwfix Live 2026

Screwfix Live, the renowned event for trade professionals and serious DIYers, returns to Farnborough International Exhibition Centre from Friday 25 to Sunday 27 September. Now in its 13th year, Screwfix Live brings together more than 200 leading trade brands, offering visitors the chance to get hands-on with the latest tools, products, and innovations, all under one roof. Attendees can also shop exclusive event-only offers and enjoy giveaways, live product demonstrations, hands-on experiences, expert Q&A sessions, and much more. Free to attend, visitors can now register to secure their place and receive a free goodie bag on arrival that Screwfix says is worth over £40. Screwfix Live will also host the final of Screwfix Top Tradesperson 2026 (which we reported on last week), where 10 finalists will face a panel of industry experts. One worthy winner will take home the ultimate £20,000 trade bundle of tools, tech, and training. Max Britten, Screwfix Managing Director, says, “Screwfix Live is an absolute highlight of the year, where we, the trade community, come together under one roof with hundreds of suppliers showcasing their fantastic products. “Last year we welcomed a record-breaking 30,000 visitors, and we're delighted to open registrations for what promises to be another incredible event. Whether you're an experienced professional or serious DIYer, there's something for everyone at Screwfix Live - and we look forward to welcoming visitors this September.” For more from Screwfix, click here.

Makita launches cordless XGT heat gun

Makita, a manufacturer of power tools and outdoor equipment, has introduced the HG001GZ02 40VMax XGT Heat Gun, a cordless model designed for professional applications requiring high temperatures and variable airflow. Powered by the company's 40V XGT battery platform, the heat gun delivers temperatures of up to 600°C and airflow rates of up to 200L/min. Makita says the tool offers performance comparable to mains-powered models while providing the flexibility of cordless operation. Supplied as a body-only unit in a Makpac carry case, the heat gun is intended for workshop and construction site use. The increased voltage compared with previous models enables applications including welding waterproof membranes and shrinking cable sleeves for cables with diameters of 25mm or greater. The tool features electronic controls that maintain consistent temperature and airflow as battery voltage changes. An LCD display and control dial allow users to adjust settings, while the last-used configuration is stored for repeated tasks. Features designed for professional use The LCD screen displays temperature, airflow settings, battery status, and system alerts. The tool also incorporates maximum temperature control. The heat gun is compatible with the nozzles used on Makita's existing cordless and mains-powered heat guns. A quick-release mechanism also allows nozzles to be removed without touching hot components. Additional features include an LED work light, a rubberised grip, and an integrated hanging hook for storage. Kevin Brannigan, Marketing Manager at Makita, says, "The new heat gun offers power, precision, and freedom to professionals looking for an efficient solution when working on thermal jobs. "The tool also comes in a versatile storage solution, keeping it well protected and easy to transport, making sure operators are ready for any task." For more from Makita, click here.

Ansell expands Foliar Connect outdoor lighting range

Lighting manufacturer Ansell Lighting has expanded its Foliar Connect outdoor lighting system with the addition of new decking lights for residential lighting installations. The new fittings are available in round and square designs with a stainless steel bezel and are rated IP66 and IK06. They feature a three-pin connector and are compatible with the Foliar Connect system's two-way and four-way splitters, allowing installers to configure lighting layouts to suit different outdoor spaces. The 24V plug-and-play system uses a central control hub, available with either manual correlated colour temperature (CCT) selection or OCTO smart app control. The wider Foliar Connect range also includes three spike-mounted luminaires in black and natural green finishes: the Planter Spike, Mini Flood Spike, and Spot Light Spike, each designed for different landscape lighting applications. System designed for flexible outdoor installations Ansell says the modular design allows luminaires to be added, repositioned, or adjusted without additional electrical work. The central hub includes a mounting bracket with a built-in spirit level to aid installation, while the spike fittings are installed using quick-fit connectors. The hub also enables users to select between 3000K and 4000K colour temperatures. The OCTO-enabled version provides additional control (including dimming and scheduling) via a smartphone or tablet. Mark Abbott, Managing Director at Ansell Lighting, explains, "The addition of the decking lights means Foliar Connect can now be applied throughout an entire garden project. "The range was specifically designed to complement landscaped environments and is perfect for subtly lighting up features such as foliage, pathways, and architectural details without disrupting the natural aesthetic, and now decking and seated areas can be included. "The system is incredibly easy to install and operate, offering users the freedom to change installation layouts and operative settings, as required, for enhanced functionality." For more from Ansell Lighting, click here.

NICEIC launches remote EV charging course

NICEIC, a certification body for the UK’s electrical contracting industry, has launched a new remote training course for the Level 3 Award in the Requirements for the Design and Installation of Domestic and Small Commercial Electric Vehicle Charging Installations (2921-34). The one-day course is designed to help electrical contractors gain a recognised electric vehicle charging point (EVCP) qualification without attending a training centre. Accredited by City & Guilds, the course is delivered remotely with live tutor-led sessions and remotely invigilated assessments. The first courses will run across five dates in July, August, and September, beginning on 31 July 2026. Learners attend live online sessions led by experienced tutors, enabling them to ask questions and receive feedback throughout the day. NICEIC says the course provides a more accessible training option for contractors while retaining the tutor-led approach to developing competence in EV chargepoint installation. Live online training aims to improve accessibility Alex Robinson, Head of Training at NICEIC, notes, "With consumer demand for electric vehicles continuing to grow, we’re seeing real-world electrification become a defining theme for the year ahead. "In 2025 alone, EV sales rose by 28%, with around one in three new cars sold now fully electric. "That pace of change means we need more contractors competent in the technology to meet demand and enable the roll-out. Our focus is to make high-quality training more accessible to electrical contractors across the UK. "This course allows us to reach those who may not be able to travel to a training centre, while still delivering the tutor-led experience that supports real understanding and competence." NICEIC is also offering a 5% discount on all virtual training courses available through its online shop between 1 July and 31 August 2026. The discount can be used alongside other promotional offers, including the existing 10% training discount for NICEIC-certified businesses. More information about the course and upcoming training dates is available through the NICEIC online shop. For more from NICEIC, click here.