Earth potential rise, touch and step voltage analysis using SES MultiFields — with reports ready for DNO and authority submission.
An earthing study is required whenever significant fault current can flow into the ground and people or equipment could be exposed to the resulting voltages: new or modified DNO connection points, HV and EHV substations (including 275 kV systems), rail traction power and return current systems, wind, solar and other generation sites, and industrial facilities with significant fault levels. DNOs and principal contractors will not accept a connection or design without the supporting earthing assessment.
A robust earthing design is a personnel safety issue first and a compliance issue second — the study is the engineering evidence that both are satisfied.
During an earth fault, the earthing system rises in potential relative to remote earth — the earth potential rise (EPR). Our studies model the soil (from Wenner or Schlumberger resistivity measurements), the electrode system and the fault current distribution to calculate EPR, touch and step voltages, and transferred potentials to nearby infrastructure. Results are assessed against the permissible limits of BS EN 50522 and ENA TS 41-24, and where limits are exceeded we optimise the electrode design until the system is compliant.
We use SES MultiFields and SES FCDIST — part of the industry-leading SES Technologies (CDEGS) suite — certified to Level 1 in MultiFields and Transient/EMI Analysis. These are the tools used on major UK and international infrastructure projects for earth electrode design, touch/step voltage analysis, and EMI assessment, and their outputs are recognised by DNOs and approval authorities.
New to the topic? Read our practical guide to earth potential rise (EPR), or see what an earthing study costs in the UK. Fault levels for earthing studies often come from network models — see our ProDesign cable calculation service.
Common questions about earthing studies, EPR and UK earthing standards.
Earth potential rise is the voltage a substation or electrode system reaches, relative to remote earth, when fault current flows into the ground. It drives the touch, step and transferred potentials that an earthing study must prove are within the safety limits of BS EN 50522 and ENA TS 41-24.
A soil resistivity survey (Wenner or Schlumberger measurements), the earth fault level and clearance time from the DNO or network operator, a site layout drawing, and details of any existing earthing or nearby third-party infrastructure. If you don't yet have soil data we can advise on the survey specification.
BS EN 50522 is the British Standard for earthing of power installations above 1 kV and sets the safety criteria. ENA TS 41-24 is the Energy Networks Association specification that applies those principles to UK distribution networks — DNOs assess connection designs against it. Most UK earthing studies must demonstrate compliance with both.
Yes. Every study is issued as a full report with the soil model, software results, touch and step voltage assessment against permissible limits, and design recommendations — the evidence DNOs, approval authorities and principal contractors expect to see.
A single-site study with complete input data typically takes one to two weeks. Larger or multi-site studies, or studies requiring soil survey coordination, take longer — we confirm the programme before starting.