VA Electrician common mistakes
VA Electrician · Understand the traps and how to avoid them.
Sizing conductors by jumping straight to the 90°C column of the ampacity table because it gives the largest number, instead of first applying the termination temperature limit and any adjustment factors.
Field habit: installers work from memory of 'what fits' and rarely recompute ampacity from scratch, so the fastest table column wins under time pressure.
What to do instead
At the top of the scratch sheet write the three-step order: termination rating (110.14(C)) caps the usable column, then apply 310.15 adjustment/correction, then check the 125% continuous-load rule. Do this even when the answer 'looks obvious'.
Blending the standard (Article 220 Part III/IV) and optional (Part V for dwellings) load-calculation methods in a single problem, or using a demand factor from one method with the totals from the other.
Both methods appear in the same article and produce plausible numbers, so candidates grab whichever factor or table they remember first.
What to do instead
Before calculating, write 'STANDARD' or 'OPTIONAL' at the top of the work and refuse to use any table that belongs to the other method. Separately memorise the 125% largest-motor adder and check it is applied exactly once.
Computing box fill by counting only the current-carrying conductors that get spliced, ignoring cable clamps, support fittings, the device yoke, and the equipment grounding conductors.
Candidates mentally 'see' the wires in the box and forget that the box fill rules count items that occupy volume without being conductors.
What to do instead
Use a fixed checklist every time: each conductor entering = 1, each EGC set = 1 (based on the largest EGC), each clamp = 1, each yoke/device = 2, each isolated hickey/stud = 1, then look up the per-conductor volume for the actual size from the volume table.
Applying one securing-and-supporting interval to every wiring method - most often using the 4½ ft / 12 in-from-box cable rule for EMT or other raceways.
Cable methods get drilled in during residential work; raceway articles have their own support rules that are rarely encountered on small jobs.
What to do instead
Build a one-page grid: method, secure-within distance of box/termination, maximum support spacing, and any exceptions for fishtape-supported or fished installations. Review it the night before the exam.
Using the branch-circuit short-circuit and ground-fault protection percentages for the motor overload device, or sizing the branch-circuit breaker at 125% of the table full-load current.
Motor articles have two separate protection systems with different rules and different tables, and candidates collapse them into one calculation.
What to do instead
Write two separate boxes on the scratch paper labelled 'branch-circuit protection' and 'overload'. Branch-circuit protection uses the table FLC with the percentage allowances; overload uses the nameplate current with the service-factor or temperature-rise percentage.
Assuming a standard raceway-and-fitting assembly (for example EMT with setscrew connectors) satisfies a Division 1 hazardous location, and treating the Division and Zone classification systems as interchangeable.
Most candidates never work in classified locations, so they reason from ordinary-location wiring methods instead of the special-occupancy article.
What to do instead
Memorise a short matrix of permitted wiring methods for Class I Division 1 vs Division 2 and Class II Division 1 vs Division 2, and note which Article 500 Articles correspond to the Article 505 Zone system. Re-derive the answer from the matrix, never from the general wiring-methods chapters.
Swapping the two grounding conductor tables - sizing the grounding electrode conductor from the overcurrent-device table, or the equipment grounding conductor from the service-conductor table.
Both tables are short, both are in Article 250, and both are indexed by a single number, so the wrong one is selected under time pressure.
What to do instead
Anchor the trigger word: 'electrode' is keyed to the largest ungrounded service conductor; 'equipment' is keyed to the rating of the overcurrent device ahead of the circuit. Say the trigger word aloud before opening a table.
Selecting answers that bond the grounded conductor to the enclosure or to the grounding bus at a subpanel, panelboard on a separate structure, or other downstream enclosure.
Candidates generalise the main-service bonding rule to every panel they have ever seen, and retrofit panels often are miswired this way.
What to do instead
Locate the single permitted bonding point (service disconnect, source of a separately derived system, or the first disconnecting means at a separate structure under the applicable condition) and treat every other enclosure as a floating-neutral enclosure. Check the neutral bus bonding screw/jumper as a separate step in every problem.
Attributing adoption of the National Electrical Code to the licensing agency, or naming the wrong Virginia body as the authority that adopts the electrical code provisions used for inspection.
Candidates prepare for the code half of the exam and assume the same agency must be behind the regulations they follow in the field.
What to do instead
Write the split on a study card: the building-code side (statewide building code and its electrical provisions, adopted by the housing and community development board) versus the licensing side (tradesman and contractor licensing under the Department of Professional and Occupational Regulation). Match each question to the correct side before answering.
Answering licensing-scope and business-practice questions from general intuition - for example, assuming any paid electrical work requires a license, that the licence class does not matter for the work performed, or guessing at renewal and continuing-education requirements.
These questions test the text of the statutes and board regulations, not trade knowledge, and candidates spend almost all their study time in the code book.
What to do instead
Tab the licensing statute and the board's regulation sections on licence classes, exemptions, supervision, renewal and continuing education, then drill them as a separate short block each study session. Answer only from the tabulated language, not from what feels reasonable.