10.6 Plan Review, Redline, and Supervisory Correction Lab

Lab scenario

You are the qualifying master electrician reviewing permit drawings for a small building renovation before signing the company review sheet. The plan set includes an electrical one-line diagram, panel schedules, lighting plan, power plan, mechanical equipment schedule, fire alarm notes, and general specifications. The drawings show a service replacement, two new tenant panels, rooftop HVAC units, exterior receptacles, LED lighting controls, a small transformer, and a future generator note. Several details conflict: the one-line shows 400 ampere service equipment, the panel schedule totals imply 520 amperes of connected load before demand, the grounding detail is copied from another project, and the rooftop disconnect notes do not match the mechanical schedule.

A master electrician is not expected to redesign the entire engineering package without authority, but is expected to catch buildability and compliance risks before the crew owns them. A redline is not just a complaint. It should identify the defect, point to the governing code area or coordination source, state the required correction, and assign responsibility when information is missing. This approach also helps on the master exam, where redline questions often ask for the best correction, not just the easiest field workaround.

First-pass review order

Start with scope and code cycle. Confirm whether the jurisdiction is using the 2023 NEC, 2020 NEC, 2017 NEC, or an amended local code. ICC R16, T16, and G16 correspond to different NEC cycles, and a local master license may adopt a different edition. Do not mix cycle-specific requirements casually. Then verify the service one-line against load calculations, available fault current, equipment ratings, grounding and bonding, service disconnect locations, and utility requirements.

Next review panel schedules and feeders. Look for spare breakers that are actually connected, two circuits on one pole where not allowed, multiwire branch circuits without required simultaneous disconnecting means, continuous lighting loads without proper sizing, and panel ratings that do not match feeder overcurrent protection. Check whether neutral loads and nonlinear loads are considered when facts require it. Confirm that tenant, house, and emergency or standby loads are not mixed without a design basis.

Then review branch circuits, wiring methods, and physical routing. Check receptacles near sinks, rooftops, outdoors, kitchens, garages, unfinished spaces, and other GFCI-triggering locations. Check AFCI where dwelling or other applicable rules require it. Confirm raceway and cable choices for wet locations, physical damage, fire-rated assemblies, environmental air spaces, corrosive locations, and rooftop exposure. Confirm box fill, conduit fill, conductor adjustment, and equipment grounding conductor continuity for the proposed methods.

Redline hierarchy

Use a risk hierarchy. Life safety and source separation defects come first. Examples include emergency loads mixed with optional loads, fire alarm power not identified, egress lighting left on a tenant panel without access, or transfer equipment not specified. Service and fault-current issues come next: missing available fault current, equipment short-circuit current rating too low, unsupported series rating, or service disconnect grouping problems. Grounding and bonding defects are next because they can be hidden after energization.

Load capacity and conductor sizing follow. A wrong load calculation can invalidate the whole service or feeder. But a wrong number is often a symptom. The correction might require a revised equipment schedule, demand calculation, service size, feeder size, or load management scheme. Do not redline only increase breaker to 225 amperes if the conductors, panelboard, fault rating, and load basis are also unresolved.

Working space and accessibility defects deserve early attention because they become expensive after framing. Electrical rooms used for storage, panels behind doors or equipment, rooftop disconnects outside safe access, and transformers without ventilation clearance should be marked before installation. Documentation defects are last in the hierarchy but still important: panel directories, circuit identification, torque labels, field marking of fault current, and as-built updates prevent future hazards.

Code-navigation plan

For each redline, write the route instead of a long quote. Example: service load calculation to service conductor sizing to overcurrent protection to available fault current marking. Example: rooftop unit nameplate MCA and MOCP to disconnect location to working clearance to wet-location wiring method. Example: transformer primary protection to secondary conductors to separately derived system bonding to panelboard grounding. This route proves that the correction is not arbitrary.

On the exam, redline questions may include four plausible corrections. Eliminate answers that ignore the stated defect, solve only a downstream symptom, or assume facts not in evidence. If the drawings omit HVAC nameplates, the best answer may be require manufacturer data before final conductor and overcurrent sizing. If the grounding detail is copied from another project, the best answer may be revise the grounding and bonding detail to match the actual service, transformer, and separately derived system arrangement.

Supervisory communication

A professional redline is concise and actionable. Write: Revise panel H schedule to identify all continuous lighting loads and recalculate feeder ampacity. Or: Provide available fault current at service equipment and verify equipment SCCR and interrupting ratings. Or: Clarify whether generator note is future only; if included, provide transfer equipment classification, load list, grounding arrangement, and signage. Avoid vague notes such as check code or electrician to verify. Those notes shift risk without fixing the drawing.

The master electrician also manages crew behavior. Do not allow installers to solve design gaps by field preference. If drawings conflict, stop and request clarification. If a material substitution changes conductor fill, grounding continuity, support, environmental rating, or equipment listing, it needs review. If the owner asks for additional circuits during rough-in, update load calculations and permits as required. Supervisory correction is an active process, not a signature at the end.

Field verification before inspection

Before inspection, walk the job against the redline log. Confirm service labeling, grounding electrode system, bonding jumpers, neutral isolation, feeder conductor sizes, panel directories, GFCI and AFCI device locations, rooftop disconnects, equipment nameplates, working clearances, firestopping, and access to junction boxes. Confirm that deferred items have either been resolved or clearly excluded. The strongest inspection preparation is a closed-loop redline process where every issue has an owner and a disposition.

For the master exam, this lab builds a habit: find the controlling defect, identify the correct rule path, and choose the correction that makes the installation coherent. Many wrong answers are familiar code fragments attached to the wrong problem. The right answer usually protects design integrity, safety, and inspectability at the same time.

Structured Decision Aid

• Read drawings, specifications, panel schedules, equipment schedules, and notes before marking corrections.
• Redline the cause of the problem, not just the symptom visible on the plan.
• Prioritize corrections by safety, code violation, inspection failure, and constructability risk.
• Write field directions with enough detail to prevent a second failed inspection.