Electrical drawing review checklist

Helonic is an AI construction drawing analysis platform for teams researching electrical drawing review checklist during drawing review. A NEC-aligned review checklist for commercial electrical construction drawings

What electrical drawings should you review?

A complete electrical review covers the E-000 series through power, lighting, fire alarm, low voltage, and Division 26 specs.

Cover, code summary, and symbol legend (E-000 series)
Site electrical plan and utility coordination
Single-line diagram
Panel schedules
Lighting plans and controls
Power plans
Fire alarm plans (separate or with electrical)
Low voltage / telecom plans (may be separate)
Riser diagrams for power, fire alarm, telecom
Details for grounding, equipment pads, equipment supports
Specifications Division 26 (Electrical)

What do you check on service and distribution?

Confirm utility coordination, service conductor sizing, AIC ratings, and the grounding electrode system before you review branch circuits.

Utility coordination form complete with utility company
Service entrance conductor sizing matches load calculation
Service short-circuit current rating documented and supported
Service entrance equipment AIC rating exceeds available fault current
Main disconnect properly identified
Service grounding electrode system shown and detailed
Bonding jumper sized per NEC 250
Generator sizing and connection (if applicable) coordinated with transfer switch

What should panelboard and branch-circuit review cover?

Panel schedules must list circuit descriptions, loads, and totals, and each panelboard AIC rating must exceed available fault current at that location.

Panel schedules complete with circuit descriptions, loads, and totals
Panelboard AIC rating exceeds available fault current at that location
Spare circuit capacity per design intent (typically 20 to 25%)
Demand factors applied per NEC Article 220
Voltage drop within design limit (typically 3% branch, 5% total)
Branch circuit conductor sizing per ampacity tables and load
Overcurrent protection sized per conductor ampacity
GFCI protection in required locations (NEC 210.8)
AFCI protection in required locations (NEC 210.12)
Tamper-resistant receptacles where required

What working clearances does NEC require at electrical equipment?

NEC 110.26 requires working clearance at every panel, switchboard, and transformer, typically 30 inches wide and 36 inches deep.

NEC 110.26 working clearance at every panel, switchboard, transformer
30" minimum width and 36" minimum depth at panel
6.5' minimum height clear of obstructions in working space
Dedicated electrical space above panels per NEC 110.26(E)
No piping, ductwork, or foreign systems in dedicated space
Egress from electrical rooms per NEC 110.26(C)

How do you review grounding and bonding on electrical drawings?

Check grounding electrode conductor sizing per NEC 250.66 and equipment grounding conductor sizing per NEC 250.122.

Grounding electrode conductor sizing per NEC 250.66
Equipment grounding conductor sizing per NEC 250.122
Bonding of structural steel, metallic water, gas, and CSST
Separately derived systems grounded and bonded
Special equipment grounding (data centers, IT spaces, healthcare)

What lighting and control items belong on an electrical review?

Lighting power density must stay within IECC or ASHRAE 90.1 limits, and occupancy sensors belong in the spaces the energy code requires.

Lighting power density within IECC / ASHRAE 90.1 limits
Occupancy sensors in required spaces (private offices, conference rooms, restrooms)
Daylight responsive controls in required daylight zones
Automatic time-of-day shutoff or scheduling
Manual switching available for all spaces
Emergency lighting circuits properly separated from normal circuits
Emergency egress illumination per IBC 1008
Exit sign locations coordinated with life-safety plan

How do you review emergency and standby power?

Emergency loads under NEC Article 700 must sit on a dedicated branch, separate from legally required and optional standby.

Emergency loads (NEC Article 700) identified and on dedicated branch
Legally required standby loads (Article 701) identified
Optional standby loads (Article 702) separated from emergency
Transfer switches sized and coordinated with normal and alternate sources
Generator fuel storage and run time meet code minimum
Annunciator location accessible per code

Reviewer Tip

Always cross-check the panel schedule against the actual circuited devices on the power and lighting plans. Phantom circuits (on the panel schedule but not on the plan) and orphan devices (on the plan but not on a panel) are the two most common electrical drawing errors.

What electrical coordination checks belong against other disciplines?

Mechanical and plumbing equipment connections on the electrical set must match those equipment schedules.

Mechanical equipment connections match mechanical schedule
Plumbing equipment connections match plumbing schedule
Fire alarm devices coordinated with fire protection
Lighting locations coordinated with reflected ceiling plan
Panel locations coordinated with architectural elevations
Conduit routes coordinated with structural openings

Keep exploring

Related references for electrical drawing review.

How to Read Electrical Drawings

Step-by-step electrical plan review.

Electrical Single-Line Diagram Guide

Reading service, switchgear, and feeders.

Electrical Plan Symbols

Visual reference for electrical symbols.

Electrical Abbreviations

100+ electrical abbreviations by category.

See Helonic on your electrical set

Helonic cross-checks panel schedules against circuited devices, validates AIC ratings, and flags grounding and clearance issues across your electrical drawings.