In short. Different electrical problems need different studies. Choosing the right one saves time and money. Start from the symptom or the project question, find the study in the table, and gather the data it needs.
Problem-to-study table
| Problem or question | Study | Page |
|---|---|---|
| Adding load or a new generator; is capacity enough? | Load list, demand and generator sizing; load flow | load flow |
| Breaker ratings uncertain; adding sources | Short-circuit study | short-circuit |
| Wrong breaker trips; blackouts from small faults | Protection coordination | coordination |
| Safety of work on live gear; labels | Arc-flash study | arc-flash |
| Voltage drops or motor start problems | Cable and voltage-drop; motor-starting study | motor starting |
| Generator stalls or trips on large start | Large motor starting on diesel generator | large-motor starting |
| Transformer energisation trips | Inrush study | energisation |
| Hot equipment, resonance, distortion | Harmonic study | harmonics |
| Low power factor, high charges | Reactive power study | reactive power |
| Unbalanced voltages; motor heating | Unbalance study | unbalance |
| Earthing, touch voltage questions | Earthing study | earthing |
| Lightning and surge damage | Lightning and surge risk | surge risk |
| Parallel generators or utility paralleling | Synchronising and interconnection study | paralleling |
| Which loads to protect and how | Critical-load classification | classification |
| Reliability and redundancy decisions | Reliability, FMEA, SPOF | FMEA |
| Future growth or brownfield upgrade | Capacity expansion; brownfield study | brownfield |
Data most studies need
- An accurate single-line diagram.
- Equipment ratings and nameplate data.
- Load list and measured demand.
- Utility supply data, including fault level.
- Cable data and lengths.
- Protection devices and settings.
Order of studies
- Validate inputs and the single-line diagram.
- Load flow and short-circuit.
- Protection coordination and arc-flash.
- Specialised studies: motor starting, harmonics, transients, reliability.
See study inputs, assumptions and validation.
When you are not sure
If the problem is vague, begin with measurement: a power-quality recording and a walk-through of the single-line diagram often indicates the right study quickly.
Problem to study
| Problem | Study | Guide |
|---|---|---|
| What size generator? | Load list, demand, sizing, transient | generator sizing |
| Motor start dips voltage | Motor-starting study | motor-starting studies |
| Breaker rating questions | Short-circuit study | short-circuit study |
| Unexpected trips | Coordination study | coordination workflow |
| Arc-flash labels needed | Arc-flash study | arc-flash study |
| Harmonic distortion | Harmonic study | harmonic studies |
| Low power factor | Reactive power study | reactive power studies |
| Parallel with the grid | Interconnection study | interconnection |
| Need to prove uptime | Reliability and FMEA | reliability |
| Old plant, uncertain records | Brownfield study | brownfield |
How to proceed
- State the problem in one sentence with the evidence.
- Choose the study from the table.
- Collect the data it needs.
- Agree acceptance criteria before the study runs.
For scoping help, use the application engineering enquiry.
Common mistakes
- Choosing equipment before understanding the problem.
- Starting studies with unverified data.
- Doing specialised studies before the short-circuit baseline.
What to send us
Send a short description of the problem, single-line diagram and any recordings. Send your application details.
Questions engineers ask
Which study should I do first?
Validate the diagram and data, then load flow and short-circuit as the base for the rest.
Do I need all of these?
No. Choose by the problem. Many sites need only a few.
How accurate must the data be?
As accurate as the decision requires. Studies are only as good as their inputs.
Can studies be done for an existing site?
Yes, with a survey to verify the as-built system.
This guide gives general principles. Study scope should be defined for your project.