REFERENCE

Connection Map

Prerequisites · which section feeds which · the path through Power Atlas

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.

Recommended Reading Order

  1. First pass — foundation. §01 → §02 → §03 → §04 → §05 → §06. The MEL → loads → branch → panel → feeder chain. After this, you can size most simple branches.
  2. Second pass — distribution depth. §07 (conductors) → §08 (tray/busway) → §09 (transformers) → §10 (service entrance). Now you can size whole-building distribution.
  3. Third pass — protection. §11 (overcurrent) → §12 (short circuit) → §13 (grounding). Required before §17 and §18.
  4. Fourth pass — motors + power quality. §14 (motors) → §15 (power quality) → §16 (load flow). Adds dynamic system understanding.
  5. Fifth pass — advanced protection. §17 (relaying) → §18 (arc flash). Builds on §11 + §12.
  6. Sixth pass — special systems. §19 (emergency) → §20 (DC) → §21 (haz loc). Each independent; pick what's relevant to your project.
  7. Seventh pass — high voltage / outdoor. §22 (substations) → §23 (lightning) → §24 (SPD).
  8. Eighth pass — modern systems. §25 (PV/ESS) → §26 (EV) → §27 (demand response).
  9. Final pass — practice + reference. §28 (drawings) → §29 (LOTO) → §30 (AHJ) → §31 (energy codes) → §32 (codes ref).

Per-Section Map

For each section: what you should already know (prerequisites) + what later sections build on it (feeds).

SectionPrerequisitesFeeds intoAtlas DC1 element used
§01 ConversionsNone — start hereEvery other sectionCH-1 chiller motor (FLA calc)
§02 How Design Starts§01§03, §28Full Atlas DC1 SLD introduction
§03 Load Analysis§01, §02§05, §06, §09, §10, §19, §27Side A complete load study
§04 Branch Circuits§01, §03§05, §06, §07, §14CH-1 branch sizing (MCA/MOCP)
§05 Panel Schedules§03, §04§06, §11, §28RPP-A1-1 schedule
§06 Feeders§03, §04, §05§07, §09, §16UPS-A1 → PDU-A1 feeder
§07 Conductors§04, §06§08, §12System-wide conductor selection
§08 Tray + Busway§06, §07§28UPS-PDU feeder routing
§09 Transformers§01, §03, §06§10, §12, §13TX-A 2500 kVA pad-mount
§10 Service + Utility§03, §09§3012.47 kV primary metered
§11 Overcurrent + Coord§04, §05, §06§17, §18, §19UPS → PDU → RPP coordination cascade
§12 Short Circuit§01 (per-unit), §09 (%Z)§17, §18, §22, §2450.3 kA at 480V SWGR-A
§13 Grounding§10, §12§18, §23Multiple separately derived systems
§14 Motors§04, §06§15 (VFD harmonics), §17Chiller 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, §22MV 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), §272N 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)§24NFPA 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)§274× L2 + 1 DCFC with EVEMS
§27 Demand Response§03, §19, §25—Mech-only shed strategy
§28 Drawings + Specs§02, §05 (schedules)§30Atlas DC1 drawing set excerpt
§29 LOTO§18 (PPE), §19 (system topology)§30UPS-A1 LOTO with 2N preserved
§30 AHJ§28 (deliverables)§31, §32Permit + inspection sequence
§31 Energy Codes—§32ASHRAE 90.4 PUE compliance
§32 Codes ReferenceAll — this is the reference index——

Where to Find Each NEC Article (cross-reference)

NEC ArticleSubjectWhere explained in Power Atlas
110.16Arc flash labels§18 (definitions), §30 (AHJ check)
110.24Available fault current marking§12 (calc), §30 (AHJ check)
110.26Working space§30 (AHJ rejections)
210Branch circuits§04
210.8 / 210.12GFCI / AFCI§04, §07
215Feeders§06
220Load calculations§03 (depth), §10 (service)
230Service entrance§10
230.67SPD at service§24, §30 (AHJ check)
230.95GFP at service§13, §30 (AHJ check)
240Overcurrent protection§11
240.21Tap conductors§06 (brief), §32
250Grounding + bonding§13 (depth)
250.30Separately derived systems§13, §09
250.66 / 250.122GEC / EGC sizing§13
285SPDs§24
310.12Residential 83% rule§07
310.15(B)/(C)Conductor derating§04, §07
310.16Conductor ampacity§04, §07 (depth)
336TC cable§07, §08
368Busway§08
392Cable tray§08
408Switchboards + panelboards§05
430Motors (full)§04 (branch), §06 (feeder), §14 (full)
430.6FLC vs nameplate§01, §04, §14
430.22MCA = 1.25 × FLC§04
430.24Multi-motor feeder§03, §06
430.32Motor overload§14
430.52MOCP table§04
430.247-250FLC tables§01, §04, §14
450Transformers§09
450.3Transformer OCPD§09
480Storage batteries§20
500-516Hazardous locations§21
505 / 506Zone system§21
517Healthcare§19 (life safety example), §30
625EV charging§26
625.42EVEMS§26
690PV systems§25
690.12Rapid shutdown§25
700Emergency systems§19, §11 (selective coord)
700.27Selective coord (life safety)§11
701Legally required standby§19
702Optional standby§19 (Atlas DC1 here)
705Interconnected sources§25
705.11Supply-side connection§25
705.12120% rule§25
706ESS§25
708COPS§19 (mention)

Connection Map v1.0 · last updated 2026-05-04