About Substation Trainer
Substation Trainer is a 3D training model of nine typical US substations, with linked drawings, guided lessons and practice tools. It was built by Locke Design Firm for new designers, technicians and engineers learning how substations are arranged, protected and worked on.
Content last reviewed: October 11, 2026.
Disclaimer
Substation Trainer is an educational model of typical U.S. utility practice. It is not a substitute for the applicable codes and regulations (NESC, NEC, OSHA, EPA, NERC), your utility's or employer's standards and work procedures, manufacturer instructions, or the judgment of a qualified engineer or qualified person. Dimensions, ratings and calculations are representative and are not for design, construction or field use. Working on or near energized equipment requires training, authorization and the protective measures your employer specifies under OSHA 29 CFR 1910.269 or 1910 Subpart S.
The certificate records participation in a self-paced, unproctored program. It does not make anyone a "qualified person" under OSHA; that is determined by the employer.
How to read the numbers
Values in the trainer fall into four kinds. Where it matters, the text says which kind a number is.
| Kind | Meaning | Example |
|---|---|---|
| Code requirement | Set by law or an adopted code. | OSHA minimum approach distances; NESC fence height of at least 7 ft |
| Standard method | From a consensus standard or guide. | IEEE 80 touch and step limits; IEEE 998 rolling sphere |
| Typical practice | Common in US utilities, but varies by company. | 8 ft fence (7 ft fabric + 1 ft barbed wire); 8 h battery duty cycle |
| Model value | A representative number chosen for the 3D model. | Equipment dimensions, cable lengths, fault levels |
The calculators show their equations and every input on screen: step and touch voltage (IEEE 80), arc flash (IEEE 1584-2002 equations, labeled as a teaching model), and the rolling sphere (IEEE 998).
References
Editions shown are the ones the content was checked against. Codes and standards are revised regularly: confirm the edition your project or employer has adopted. Where the edition is marked "check", the current status should be confirmed with the publisher.
Regulations
| Reference | Edition | Used for |
|---|---|---|
| OSHA 29 CFR 1910.269 and App. B | current eCFR | Qualified-worker minimum approach distances (Tables R-6, R-7, altitude Table R-5), switching and grounding work practices |
| OSHA 29 CFR 1910.333(c)(3) | current eCFR | Unqualified-person distance: 10 ft up to 50 kV, plus 4 in per 10 kV above |
| OSHA 29 CFR 1910.151(c) | current eCFR | Eyewash near battery electrolyte |
| EPA 40 CFR 112 (SPCC) | current eCFR | Oil spill prevention; 112.7(c) general secondary containment and the 112.7(k) alternative for oil-filled operational equipment |
| EPA 40 CFR 98 Subpart DD | current eCFR | SF6 greenhouse gas reporting |
| NERC Reliability Standards | current | PRC-005 protection maintenance; CIP cyber and physical security (CIP-014, CIP-015) |
Codes
| Reference | Edition | Used for |
|---|---|---|
| National Electrical Safety Code (NESC), IEEE C2 | 2023 | Fence and sign rules (110A), clearances, utility work rules (Rule 410 arc flash) |
| NFPA 70, National Electrical Code | 2023 (check 2026) | Scope (90.2), arc-flash labels (110.16), equipment over 1000 V (Art. 495, formerly 490), PV (690/691) |
| NFPA 70E, Electrical Safety in the Workplace | 2024 | Arc-flash labels (130.5(H)), shock approach boundaries (Table 130.4(E)(a)), energized work justification (110.2, 130.2) |
| NFPA 850, Fire Protection for Electric Generating Plants | check | Plant switchyard fire protection |
IEEE and ANSI standards
| Standard | Edition | Used for |
|---|---|---|
| IEEE 80, Safety in AC Substation Grounding | 2013 (check status) | Tolerable touch and step voltage, grid design basics |
| IEEE 998, Direct Lightning Stroke Shielding | 2012 (check) | Rolling sphere radius S = 8·k·I0.65 |
| IEEE 1427, Electrical Clearances in Air-Insulated Substations | 2020 | Phase-to-ground and phase-to-phase clearances |
| IEEE 605, Bus Design in Air-Insulated Substations | 2008 | Rigid bus, expansion fittings |
| IEEE 980, Containment and Control of Oil Spills in Substations | check | Oil containment design basis |
| IEEE 1584, Arc-Flash Hazard Calculations | 2002 equations used; 2018 is current | Arc-flash calculator (teaching model) |
| IEEE C37.2, Device Function Numbers | current | ANSI device numbers in the glossary and drawings |
| IEEE C57.13, Instrument Transformers | current | CT and VT ratings, accuracy classes, secondary voltages |
| IEEE C57.15, Step-Voltage Regulators | current | Regulator ratings (kVA on the ±10% range) |
| IEEE C62.11 / C62.22, Surge Arresters | current | Arrester ratings and MCOV selection |
| IEEE 485 / 450 / 1188, Station Batteries | current | Battery sizing, float voltage, maintenance |
| IEEE C37.118, Synchrophasors | current | PMU reporting rates |
| ANSI C84.1, Service Voltage Ranges | current | Range A and B voltage limits |
| ANSI C29 series, Insulators | current | Station post and bell dimensions |
Government and design guides
- USDA RUS Bulletin 1724E-300, Design Guide for Rural Substations: bus-arrangement relative cost (Table 4-1), conductor height above grade (Table 4-7), general practice.
- EPA, SPCC Guidance for Regional Inspectors: oil-filled operational equipment versus bulk storage containers.
- FERC and NERC orders on CIP-015 (internal network security monitoring).
Textbooks
- J. D. McDonald (ed.), Electric Power Substations Engineering, CRC Press.
- J. L. Blackburn and T. J. Domin, Protective Relaying: Principles and Applications.
- S. H. Horowitz and A. G. Phadke, Power System Relaying.
Corrections log
| Date | Correction |
|---|---|
| Oct 11, 2026 | Minimum approach distances above 72.5 kV corrected to OSHA 1910.269 App. B Tables R-6/R-7 (phase-to-ground, ≤900 m). The old table understated the qualified-worker MAD at 345 kV (3.07 m, now 3.41 m) and 500 kV (3.69 m, now 5.07 m). Added the 362–420 kV and 550–800 kV bands and the source on screen. |
| Oct 11, 2026 | Industrial trip trace: removed a 65K utility link that could not coordinate above the customer's 150E fuses; the utility device is now described as sized and checked on a TCC by the utility. |
| Oct 11, 2026 | Oil containment: SPCC wording corrected (general secondary containment or the 112.7(k) alternative for oil-filled equipment; 110% applies to bulk storage). Design basis attributed to IEEE 980. |
| Oct 11, 2026 | Smaller fixes: NESC fence height (7 ft overall required, 8 ft typical); box substation arrester MCOV; IEEE 80 status note; CIP-015; PMU reporting rate; IPB fault current; CCVT voltage divider; box T1 cooling ONAN/ONAF/ONAF; bus-study costs from RUS Table 4-1; charger float voltage; metering CT ratio; height above grade from RUS Table 4-7; generator MW; 40 cal/cm² wording; certificate wording. |
| Oct 9, 2026 | PT secondary (120 V phase-to-phase / 69.3 V phase-to-ground); fault-interrupting devices (breakers, reclosers and fuses, not disconnects); battery duty cycle per IEEE 485; overstatements on isolated phase bus and exothermic welds; transformer differential explanation; regulator kVA rating; exact foundation dimensions in the BOM; body weight and surface layer inputs shown for step and touch. |
Report an error
If you find a value that disagrees with a code, standard or manufacturer's data, please send the page, the value and the source to Locke Design Firm. Corrections are logged above.