Connection Map
Reading order isn't strict, but some sections require background from earlier ones. This map shows what each section assumes and what it leads to.
The Graph — All 39 Sections at a Glance
Rows are the 13 Parts. Lines are the major prerequisite paths — not every dependency, just the spine. Use this to plan a reading sweep or to find what feeds a section you're stuck on.
Click any node to jump to that section. The spine (filled) sections are high-leverage — they feed many downstream chapters. If you only had time for ten sections, take §00, §01, §03, §04, §05, §06, §09, §11, §12, §18.
Recommended Reading Order
- Step 0 — read first if EE is new to you. §00 Theory Foundations. V/I/R, Ohm's Law, KVL/KCL, AC vs DC, sinusoid, 3-phase, transformers, R/L/C, impedance, phasors, hill metaphor, ELI/ICE. After §00, the formulas in §01 stop being memorization.
- First pass — foundation. §01 → §02 → §03 → §04 → §05 → §06. The MEL → loads → branch → panel → feeder chain. After this, you can size most simple branches.
- Second pass — distribution depth. §07 (conductors) → §08 (tray/busway) → §09 (transformers) → §10 (service entrance). Now you can size whole-building distribution.
- Third pass — protection. §11 (overcurrent) → §12 (short circuit) → §13 (grounding). Required before §17 and §18.
- Fourth pass — motors + power quality. §14 (motors) → §15 (power quality) → §16 (load flow). Adds dynamic system understanding.
- Fifth pass — advanced protection. §17 (relaying) → §18 (arc flash). Builds on §11 + §12.
- Sixth pass — special systems. §19 (emergency) → §20 (DC) → §21 (haz loc). Each independent; pick what's relevant to your project.
- Seventh pass — high voltage / outdoor. §22 (substations) → §23 (lightning) → §24 (SPD).
- Eighth pass — modern systems. §25 (PV/ESS) → §26 (EV) → §27 (demand response) → §37 (BESS deep dive).
- Ninth pass — data center specialization. §35 (liquid cooling) → §36 (AI/HPC). Required if you're working on AI training clusters or DLC retrofits.
- Practice pass. §28 (drawings) → §29 (LOTO) → §30 (AHJ) → §33 (Revit) → §34 (closeout/Cx) → §38 (specs/CA). The construction-administration arc — what you do after the design lands.
- Reference (always available). §31 (energy codes) and §32 (codes ref). Lookup, not linear reading.
Per-Section Map
For each section: what you should already know (prerequisites) + what later sections build on it (feeds).
| Section | Prerequisites | Feeds into | Atlas DC1 element used |
|---|---|---|---|
| §00 Theory Foundations | None — read first if EE is new to you | §01 (formulas), §08 (R/L/C), §09 (transformers), §12 (per-unit), §15 (phasors) | — (concept primer; no Atlas DC1 element) |
| §01 Conversions | §00 (recommended for newcomers) | Every other section | CH-1 chiller motor (FLA calc) |
| §02 How Design Starts | §01 | §03, §28 | Full Atlas DC1 SLD introduction |
| §03 Load Analysis | §01, §02 | §05, §06, §09, §10, §19, §27 | Side A complete load study |
| §04 Branch Circuits | §01, §03 | §05, §06, §07, §14 | CH-1 branch sizing (MCA/MOCP) |
| §05 Panel Schedules | §03, §04 | §06, §11, §28 | RPP-A1-1 schedule |
| §06 Feeders | §03, §04, §05 | §07, §09, §16 | UPS-A1 → PDU-A1 feeder |
| §07 Conductors | §04, §06 | §08, §12 | System-wide conductor selection |
| §08 Tray + Busway | §06, §07 | §28 | UPS-PDU feeder routing |
| §09 Transformers | §01, §03, §06 | §10, §12, §13 | TX-A 2500 kVA pad-mount |
| §10 Service + Utility | §03, §09 | §30 | 12.47 kV primary metered |
| §11 Overcurrent + Coord | §04, §05, §06 | §17, §18, §19 | UPS → PDU → RPP coordination cascade |
| §12 Short Circuit | §01 (per-unit), §09 (%Z) | §17, §18, §22, §24 | 50.3 kA at 480V SWGR-A |
| §13 Grounding | §10, §12 | §18, §23 | Multiple separately derived systems |
| §14 Motors | §04, §06 | §15 (VFD harmonics), §17 | Chiller VFD selection |
| §15 Power Quality | §14 (VFD), §09 (K-factor xfmr) | §25 (PV inverters) | Server harmonics @ PCC |
| §16 Load Flow | §01, §06, §09 | §15 (PF correction) | Voltage profile utility → rack |
| §17 Relaying | §11, §12 | §18, §19, §22 | MV switchgear protection scheme |
| §18 Arc Flash | §12, §13, §17 | §29 (LOTO PPE) | Bus-by-bus AF profile |
| §19 Emergency + Standby | §03, §11, §14 | §20 (UPS battery), §27 | 2N gen + ATS topology |
| §20 DC Systems | §19 (UPS context) | §21 (battery rooms) | VRLA 540V strings |
| §21 Hazardous Locations | §20 (battery hydrogen) for DC context | — | Battery rooms Class I Div 2 |
| §22 Substations | §09, §12, §17 | §23 (lightning) | (Atlas DC1 has no on-site substation; refers to hyperscale alt) |
| §23 Lightning | §13 (grounding) | §24 | NFPA 780 Class I LPS |
| §24 SPD | §23 (lightning context) | — | Cascaded Type 1/2/3 SPDs |
| §25 PV + ESS | §05 (panel busbar), §15 (inverter harmonics) | §27 (peak shaving) | 200 kW rooftop PV + 500 kWh ESS |
| §26 EV Charging | §03 (continuous load), §04 (sizing) | §27 | 4× L2 + 1 DCFC with EVEMS |
| §27 Demand Response | §03, §19, §25 | — | Mech-only shed strategy |
| §28 Drawings + Specs | §02, §05 (schedules) | §30 | Atlas DC1 drawing set excerpt |
| §29 LOTO | §18 (PPE), §19 (system topology) | §30 | UPS-A1 LOTO with 2N preserved |
| §30 AHJ | §28 (deliverables) | §31, §32 | Permit + inspection sequence |
| §31 Energy Codes | — | §32 | ASHRAE 90.4 PUE compliance |
| §32 Codes Reference | All — this is the reference index | — | — |
| §33 Revit | §02 (drawings context), §05 (schedules) | §34 (model handover), §38 (spec coordination) | Atlas DC1 BIM model — families + BEP |
| §34 Closeout + Cx | §28 (drawings), §29 (LOTO), §30 (AHJ) | §38 (CA workflows) | Cx levels (1-5), FAT/SAT/IST sequence, turnover docs |
| §35 Liquid Cooling | §03 (loads), §14 (CDU pumps as motors), §19 (CDU on emergency) | §36 (AI/HPC enables DLC) | CDU electrical loads, leak-detection circuits, CRAH→DLC retrofit |
| §36 AI/HPC Design | §02 (SLD scaling), §03 (rack loads), §35 (DLC required > ~30 kW/rack) | §37 (BESS for ramp absorption) | 50–250 kW/rack densities, GPU clusters, tokens-per-watt KPI |
| §37 BESS Deep Dive | §19 (emergency context), §20 (DC concepts), §25 (ESS basics) | §27 (DR + peak shave), §36 (AI ramp absorption) | Li-ion vs LFP chemistry, NFPA 855 setbacks, frequency regulation |
| §38 Specs + CA | §28 (drawings), §30 (AHJ), §33 (Revit), §34 (Cx) | — (terminal section — closes the design-to-construction loop) | CSI Division 26 specs, RFI/submittal/CO workflows |
Where to Find Each NEC Article (cross-reference)
| NEC Article | Subject | Where explained in Power Atlas |
|---|---|---|
| 110.16 | Arc flash labels | §18 (definitions), §30 (AHJ check) |
| 110.24 | Available fault current marking | §12 (calc), §30 (AHJ check) |
| 110.26 | Working space | §30 (AHJ rejections) |
| 210 | Branch circuits | §04 |
| 210.8 / 210.12 | GFCI / AFCI | §04, §07 |
| 215 | Feeders | §06 |
| 220 | Load calculations | §03 (depth), §10 (service) |
| 230 | Service entrance | §10 |
| 230.67 | SPD at service | §24, §30 (AHJ check) |
| 230.95 | GFP at service | §13, §30 (AHJ check) |
| 240 | Overcurrent protection | §11 |
| 240.21 | Tap conductors | §06 (brief), §32 |
| 250 | Grounding + bonding | §13 (depth) |
| 250.30 | Separately derived systems | §13, §09 |
| 250.66 / 250.122 | GEC / EGC sizing | §13 |
| 285 | SPDs | §24 |
| 310.12 | Residential 83% rule | §07 |
| 310.15(B)/(C) | Conductor derating | §04, §07 |
| 310.16 | Conductor ampacity | §04, §07 (depth) |
| 336 | TC cable | §07, §08 |
| 368 | Busway | §08 |
| 392 | Cable tray | §08 |
| 408 | Switchboards + panelboards | §05 |
| 430 | Motors (full) | §04 (branch), §06 (feeder), §14 (full) |
| 430.6 | FLC vs nameplate | §01, §04, §14 |
| 430.22 | MCA = 1.25 × FLC | §04 |
| 430.24 | Multi-motor feeder | §03, §06 |
| 430.32 | Motor overload | §14 |
| 430.52 | MOCP table | §04 |
| 430.247-250 | FLC tables | §01, §04, §14 |
| 450 | Transformers | §09 |
| 450.3 | Transformer OCPD | §09 |
| 480 | Storage batteries | §20 |
| 500-516 | Hazardous locations | §21 |
| 505 / 506 | Zone system | §21 |
| 517 | Healthcare | §19 (life safety example), §30 |
| 625 | EV charging | §26 |
| 625.42 | EVEMS | §26 |
| 690 | PV systems | §25 |
| 690.12 | Rapid shutdown | §25 |
| 700 | Emergency systems | §19, §11 (selective coord) |
| 700.27 | Selective coord (life safety) | §11 |
| 701 | Legally required standby | §19 |
| 702 | Optional standby | §19 (Atlas DC1 here) |
| 705 | Interconnected sources | §25 |
| 705.11 | Supply-side connection | §25 |
| 705.12 | 120% rule | §25 |
| 706 | ESS | §25 |
| 708 | COPS | §19 (mention) |
Connection Map v1.0 · last updated 2026-05-04