When electrical systems fail in a commercial or industrial environment, the impact is immediate: production slows, safety margins narrow, and costs rise. Many faults look similar on the surface—nuisance tripping, intermittent outages, erratic motor behaviour—but the root causes often hide deep within design decisions, protection settings, ageing infrastructure, or control logic. This is where SCI’s diagnostic approach stands apart.
Founded and led by Keith Walton—an experienced electrical and mechanical engineer—SCI brings engineering rigour to commercial fault finding. We combine deep technical analysis with disciplined on-site process to pinpoint causes quickly, resolve issues with minimal disruption, and leave systems safer and more reliable for the long term.
This article explains how we work, why engineering leadership matters, and what outcomes you can expect when the fault is anything but straightforward.
What Makes Commercial Faults So Complex?
Commercial and industrial sites are not simple ring mains and consumer units. They are layered systems with interdependent components:
- Three-phase distribution with selective protection and discrimination requirements
- Variable speed drives (VSDs), soft starters, and power factor correction
- Building management systems (BMS) and PLC-based control
- Emergency systems (fire alarms, emergency lighting, life safety supplies)
- Legacy circuits integrated with new equipment
- Harmonic-rich loads and sensitive electronics
When something goes wrong, multiple symptoms can mask the real failure. Untangling these paths requires method, measurement, and experience.
The SCI Difference: Engineering at the Core
Keith Walton’s engineering background sets the tone for SCI’s method. We treat every fault like a technical investigation, not a trial-and-error exercise.
1) Structured Diagnostics
We follow a clear sequence:
- Define the fault precisely: When does it occur, under what loads, after what changes?
- Stabilise the environment: Ensure safe conditions, isolate variables, and avoid cascading failures.
- Test hypotheses with data: Use calibrated instruments and, where needed, temporary monitoring to confirm or rule out causes.
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Fix and validate: Apply the remedial action, then verify with repeatable tests and documentation.
2) Advanced Instrumentation
We use calibrated test equipment suited to complex environments:
- Power quality analysers to capture harmonics, transients, flicker, and sags/swells
- Clamp meters and inrush current logging for accurate start-up profiling
- Thermal imaging to identify hidden heating at terminations and within panels
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Data logging on key circuits to identify intermittent faults over time
3) System-Level Thinking
We look beyond the failed component. SCI assesses how loads interact, how controls respond, and how future expansions will change fault levels.
4) Documented, Compliant Outcomes
We provide clear reporting—fault description, test results, root cause analysis, actions taken, and any recommendations. This supports compliance under BS 7671 and the Electricity at Work Regulations.
Deep Dive Case Study: Capacity Assessment for Site Expansion
Instead of relying on generic rule-of-thumb calculations, SCI brings data-driven engineering rigor to every system assessment. The following case study illustrates our approach to validating capacity for a major site expansion at a commercial facility with an existing 200A, three-phase main supply. This demonstrates how deep analysis uncovers critical hidden constraints that simple inspections miss.
The Challenge
A facility needed to determine if its existing main supply could support a significant new load for a planned expansion. Initial checks suggested ample headroom, but the risk of overloading an existing, complex system was too high without verifiable data.
The SCI Engineering Approach
Structured 10-Day Load Profile Logging:
We deployed advanced power quality analysers to capture a high-resolution, ten-day profile of the actual concurrent consumption on all three phases.
- The analysis established an average usage ranging between 20 and 65 amps.
- The current concurrent usage never exceeded 100 amps on any of the phases.
- Unbalanced Load and Time-of-Use Assessment:
Our analysis immediately highlighted that the phases were not balanced. By correlating usage peaks with known facility operations, we determined the nature of the loading on each phase:
- Phase 2 hit its high demand between 16:00 and 19:00, coinciding with residential-style activities such as washing and cooking.
- Phase 3 had the highest overall peaks and was utilized most of the day, suggesting a continuous working-day load and the presence of induction equipment causing random high peaks.
Distinguishing Spikes from Sustained Faults:
We identified that while each phase could randomly spike throughout the day, these spikes only lasted for a few seconds. We concluded that these are likely inrush currents or external factors, and not a sustained overcurrent. This verified that the facility’s BS88 200A fuses were operating correctly—these are designed to last indefinitely at their maximum rated current (200A) and are only designed to interrupt a circuit when a fault occurs.
Critical External Network Capacity Audit (The Hidden Constraint):
This system-level step proved the most critical. While the client’s internal system showed potential headroom, a critical investigation into the local utility’s records revealed that the supplying Pole-Mounted Transformer (PMT) was already running at 90% of its 200kVA rating (180kVA utilized). This left a minimal spare network capacity of only 20kVA.
Outcome and Strategic Recommendations
- Internal Capacity: Given the results, we determined it should be possible to take an additional supply, but advised a precautionary limit of 60 amps per phase (44.47 kVA) to allow for fluctuations not captured and colder weather usage.
- External Constraint: The analysis revealed the ultimate bottleneck was the external network capacity allocated by the utility. Any further load increase would likely require upgrading the existing transformer or installing a ground-mounted substation, involving legals and surrendering a plot of land.
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Actionable Strategy: By upgrading the existing lighting to LED and completing necessary load balancing, we believed powering the new facility would be possible within the existing network’s 20kVA spare capacity.
This depth of analysis—combining on-site data logging, detailed phase profiling, protection system expertise, and external network capacity assessment—is how SCI transforms a simple capacity question into a comprehensive, risk-mitigated, engineering-led solution.
Why Keith Walton’s Engineering Background Matters
Leadership grounded in engineering shifts the conversation from symptoms to systems. Practical benefits include:
- Correct interpretation of protection and discrimination curves
- Accurate load and fault level calculations for expansions and upgrades
- Integration of mechanical considerations (cooling, vibration) that affect electrical reliability
- Informed selection of materials and devices based on real duty cycles, not catalogue assumptions
- Effective liaison with OEMs, insurers, and auditors using technical evidence rather than anecdote
Safety and Compliance Built Into Every Step
Fault finding is not only about getting you running again. It is about ensuring the system is safe and compliant:
- Testing to BS 7671 with calibrated equipment
- Clear records: Electrical Installation Certificates (EIC), Minor Works Certificates, and updates to EICRs
- Verification of earthing and bonding integrity after any intervention
- Recommendations to improve selectivity and reduce future risk
Long-Term Reliability: Designing Out Recurring Problems
SCI aims to design out future failures by:
- Addressing root causes rather than treating symptoms
- Improving protection coordination and RCD/RCBO selectivity
- Reducing harmonic stress and neutral loading
- Ensuring accurate as-fitted documentation to support maintenance
Conclusion: Fast Answers, Safer Systems, Fewer Repeat Visits
Commercial fault finding demands more than replacement parts. It requires engineering logic, quality measurements, and disciplined execution. Under Keith Walton’s leadership, SCI delivers all three. We resolve difficult faults quickly, keep your operations running, and leave your electrical systems safer, better documented, and more resilient. To discuss a current issue or arrange a diagnostic survey, contact SCI. We will provide a structured plan to find the root cause and fix it—safely and efficiently.