Protection Studies
Clear faults selectively. Keep healthy circuits running.
HV and LV protection coordination studies to assess how your relays, circuit breakers and fuses work together. Identify grading gaps, review settings and plan changes with a clear engineering basis.
HV + LV
Protection coordination
ETAP + SKM
Power system modelling
New + existing plant
Design and operating reviews
Settings + actions
Clear engineering deliverables
When you need this
Has your plant changed?
Have your settings kept up?
New equipment, unexplained trips or inherited settings can be reasons to review how the protection operates across your network.
Select anything that applies to your site.
Outcomes & business value
Confidence in what trips — and when.
Limit the disruption
Identify where protection may trip more of the network than necessary, and assess options to improve selectivity and continuity of supply.
Manage equipment & safety risk
Review fault clearance against equipment limits and assess how protection changes could reduce arc flash incident energy.
Make informed changes
Give your team a documented basis for settings, priorities and plant modifications, with limitations and follow-up actions clearly recorded.
Scope & typical deliverables
A coordinated view of your protection.
The study boundary, operating scenarios and protection functions are agreed around your site and the problem you need to solve.
Network & fault-level review
Review the network model, source data and relevant fault levels across agreed normal and alternative operating arrangements.
Grading & selectivity assessment
Grading & selectivity assessment Assess overcurrent and earth-fault coordination between relays, breakers and fuses, including relevant equipment withstand and starting characteristics.
Settings & scheme review
Develop recommended settings and identify coordination constraints. Where needed, scope a review of main and backup protection or other scheme interfaces.
Mitigation & plant changes
Compare practical options for settings changes or protection upgrades, including their implications for arc flash assessment and future plant modifications.
What you receive
Findings your team can act on.
- Protection coordination report with the study basis, assumptions and limitations
- Time–current grading curves for the agreed devices and scenarios
- Recommended settings schedule, with the basis for proposed changes
- Coordination gaps and prioritised recommendations
- Model outputs and an engineering review of the findings
Agree at scoping: site data collection, native model handover, arc flash recalculation, settings implementation and commissioning or testing support.
Our approach
From site information to a clear action plan.
Agree the boundary and gather the evidence
We confirm your objectives, network boundary and operating arrangements, then identify the diagrams, settings and equipment information needed. Gaps in site records are captured in the scope.
Build or review the network model
We review an existing ETAP or SKM model, or build one from agreed data. Sources, transformers, cables and protection devices are checked against the information available for the operating plant.
Assess operation across the agreed scenarios
We examine fault levels, device characteristics and grading margins to identify coordination gaps. Equipment limits, load behaviour and the interfaces between protection schemes are considered within the agreed scope.
Compare changes and explain the trade-offs
We prepare recommended settings and practical remediation options, recording residual limitations. Where incident energy is a concern, arc flash recalculation can be scoped to assess the proposed changes.
Review the findings and plan implementation
We walk your team through the report, settings schedule and action priorities. Responsibilities for approval, settings changes, testing and updating site records are agreed before implementation.
Across the assets you operate
- Utilities
- BESS
- Wind
- Solar
- Mining & Industrial
- Data Centres
Case Study
NovaSource
Utility-scale solar
Protection review & incident energy mitigation options
A practical path to reducing arc flash risk.
At a solar facility, RelyOn reviewed protection arrangements following high incident energy findings. The work assessed fault-clearing behaviour and modelled mitigation options, giving the client a basis for staged protection improvements.
Related services
Arc Flash Studies — AC & DC
Assess incident energy and the effect of protection changes.
Engineering & Technical Consulting
Explore our wider engineering and asset assurance services.
FAQ's
Before you scope a study.
What information do you need from us?
Current single-line diagrams, relay settings files, circuit-breaker and fuse details, CT ratios, transformer and cable data, and available network fault levels. Previous studies and operating arrangements are also useful. We can identify data gaps and scope site collection where required.
Can you review an existing ETAP or SKM model?
Yes. We first check the model version, completeness and available supporting records, then agree the validation and updates required. The extent of model handover is included in the agreed deliverables.
Will changing protection settings reduce arc flash energy?
It may. Faster fault clearance can reduce incident energy, but changes also affect selectivity and equipment protection. The effect needs to be calculated for the relevant operating conditions. Arc flash recalculation can be included in the scope.
Does the study include changing settings on site?
The study provides recommendations and a settings schedule for review. Uploading settings, switching, testing and commissioning require a separately agreed scope, responsibilities and change-control process.
Do you cover BESS, solar and wind facilities?
Yes. We scope the relevant site network and protection interfaces, with manufacturer information needed for inverter-based sources. DC protection, specialist schemes and grid-connection compliance requirements should be identified at scoping so the study boundary is clear.
How long does a protection study take?
Timing depends on the network size, data quality, operating scenarios and review requirements. Once the scope and data needs are understood, we provide a programme with the proposal, including any dependencies on site access or third-party information.
Start with your circuit
Tell us what is changing — or what keeps tripping.
Bring your single-line diagram, existing study or the problem you are trying to resolve. We’ll help define the study boundary, information needed and next steps.
Prefer to speak with the team?
1300 15 66 85
