Electrical Plan Review Checklist: 10 Issues to Catch Before Submittal

Electrical drawings generate some of the highest correction rates at plan review. The NEC is dense, panel schedules have a lot of fields to get right, and electrical work touches every other discipline through power feeds, lighting, fire alarm, and emergency systems. A single missing fault current calculation or an incomplete panel schedule can trigger a correction cycle.

This checklist covers the 10 most common issues that electrical plan reviewers flag. It is organized roughly in the order you would check a drawing set, from service entrance through branch circuits.

Service and distribution

1. Available fault current at the service entrance

NEC 110.24 requires the available fault current to be documented at the service entrance equipment. This is one of the most commonly missing items on electrical drawings. The fault current value must be shown on the drawings or in the panel schedules, and the equipment ratings (AIC ratings on breakers and panels) must be equal to or greater than the available fault current. If the utility has not provided the fault current data yet, note it on the drawings with a commitment to update before construction.

2. Service entrance sizing and overcurrent protection

Verify that the service entrance conductor sizing matches the overcurrent protection and the calculated load. NEC Article 220 covers load calculations, and Article 230 covers service entrance requirements. Common errors include: undersized neutral conductors (especially with nonlinear loads), missing main bonding jumper callouts, and service entrance conductors that do not match the utility transformer capacity. If the service is over 1,200 amps, ground fault protection is required per NEC 230.95.

3. Grounding electrode system

The grounding electrode system should be shown on the site plan or electrical riser diagram. NEC Article 250 requires the grounding electrode conductor sizing to be documented and the electrode types to be identified (concrete- encased electrode, ground rods, water pipe, building steel). A common oversight is not showing the bonding of the grounding electrode conductor to the service equipment or not identifying supplemental electrodes when required.

Panel schedules and branch circuits

4. Complete panel schedules

Every panel schedule should show: circuit number, breaker size, wire size, conduit size, circuit description, connected load (VA), and phase assignment. Plan reviewers flag incomplete schedules more than almost any other electrical item. Check that the total connected load is summed, that the demand load calculation is shown, and that the panel feed (main breaker, feeder conductor, and conduit) is properly sized for the demand load. Spare capacity is good practice but should not mask an overloaded panel.

5. Voltage drop calculations

NEC 210.19(A) Informational Note and 215.2(A)(3) Informational Note recommend a maximum 3% voltage drop on branch circuits and 5% total (feeder plus branch). While these are informational notes rather than mandatory requirements, most plan reviewers expect to see voltage drop calculations for feeders exceeding 100 feet and for sensitive loads. Some jurisdictions have adopted local amendments making voltage drop limits mandatory. Include the calculations on the drawings or reference a voltage drop schedule.

6. Wire and conduit sizing

Cross-check wire sizes against NEC Table 310.16 (or 310.15 for ambient temperature and conduit fill corrections). Conduit fill should comply with NEC Chapter 9, Table 1 (40% fill for three or more conductors). Common errors include: using 75-degree column ratings for conductors terminated on 60-degree equipment (NEC 110.14(C)), not derating for more than three current-carrying conductors in a conduit, and not accounting for ambient temperature corrections in hot environments like mechanical rooms or rooftops.

Safety and emergency systems

7. Arc flash hazard analysis

NEC 110.16 requires arc flash warning labels on equipment likely to require examination, adjustment, servicing, or maintenance while energized. Most jurisdictions now expect either a reference to an arc flash study (per IEEE 1584) or a note committing to provide labels before energization. For utility substation work, NFPA 70E and IEEE 1584 provide the calculation methodology. Show the incident energy levels on the one-line diagram or provide a separate arc flash schedule.

8. Emergency and standby power

If the project includes emergency power (NEC Article 700), legally required standby power (Article 701), or optional standby power (Article 702), the drawings need to show: the generator or battery sizing calculations, the automatic transfer switch location and ratings, the emergency load summary, and the separation of emergency circuits from normal circuits. Emergency circuits must be in dedicated raceways and cannot share enclosures with normal circuits. A missing emergency load summary is a common first-round comment.

Coordination

9. Fire alarm system coordination

The fire alarm system is often designed by a specialty contractor, but the electrical drawings need to show the dedicated circuit for the fire alarm control panel (FACP), the location of the FACP, and the point of connection to the building's electrical system. Per NEC 760.41, the fire alarm circuit must be on a dedicated branch circuit with no other loads. Verify that the FACP location shown on the electrical drawings matches the fire protection drawings.

10. Mechanical equipment connections

Every piece of mechanical equipment on the HVAC schedules should have a corresponding circuit on the electrical panel schedules. Cross-reference the equipment nameplate data (voltage, phase, MCA, MOCP) on the mechanical schedules against the electrical panel schedule entries. Common coordination errors include: disconnect switches not shown at equipment, circuit breaker sizes that do not match the MOCP on the mechanical schedule, and missing variable frequency drive (VFD) circuits for equipment that requires them.

Catching these issues before submittal

Electrical drawings have more cross-references than most other disciplines. A panel schedule connects to the load calculations, which connect to the feeder sizing, which connects to the fault current study, which connects to the equipment AIC ratings. Missing one piece creates a chain of comments. Running through this checklist, or using an automated review tool to flag these categories systematically, saves time on every project.