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
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
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