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MASTER NEC 2023

Master Electrician Practice Test 21 – Advanced Load Calculations

This is Master Electrician Practice Test 21 — Advanced Load Calculations, going beyond basic dwelling calculations into the commercial, multifamily, and existing-building math that separates a master from a journeyman. The test has 25 multiple-choice questions on demand factors for receptacles and kitchen equipment, neutral load sizing, evaluating existing loads with real demand data, show windows and signs, and combining continuous with noncontinuous loads. Pass score is 70%. Every question includes a full NEC 2023 explanation so you can trace each answer back to the exact code section.

TOPICS COVERED

Advanced Load Calculations

How this test works

Read each question carefully

Look for absolute words like always / never — they often distinguish the right answer.

Manage your time

You have 45 min for 16 questions. Skip tough ones and come back.

Progress is auto-saved

Your answers are saved locally — a page refresh won't lose your work.

Review your answers

After submitting you'll see every explanation and your NEC references.

Frequently Asked Questions

Yes — completely free with no signup required. All answers include detailed explanations.

Requirements vary by state but typically include 4–8 years of documented electrical work experience plus a valid Journeyman license.

Advanced NEC code interpretation, load calculations, service entrance design, motor controls, generator systems, and electrical system design.

The Master exam focuses more on design, calculations, and planning rather than installation details. Load calculation and service sizing questions are weighted heavily.

Before You Start

25 questions — multiple choice
45 minutes to finish (timer starts when you begin)
Pass score is 70% — you need at least 18 correct answers
Full NEC 2023 explanation shown for every question after you submit
Keep a pencil and paper handy — several questions need real math, not just a code lookup

Topics in This Test

Dwelling general lighting demand factor — first 3000VA at 100% (NEC Table 220.42)
Optional dwelling calculation — 100% of first 10kVA plus 40% of the rest (NEC 220.82)
Optional multifamily calculation — demand factor drops as unit count rises (NEC 220.84)
Non-dwelling receptacle load demand — first 10kVA at 100%, rest at 50% (NEC Table 220.44)
Feeder/service neutral demand factor — 70% of unbalanced load over 200A (NEC 220.61)
Neutral demand factor restriction for nonlinear 3-phase loads (NEC 220.61)
Evaluating existing loads with real demand data (NEC 220.87)
220.87 calculation — 125% of maximum demand plus new load
220.87 restriction where solar, wind, or peak shaving is present
Show window unit load — 200 VA per linear foot (NEC 220.43)
Fixed appliance demand factor — 75% for four or more appliances (NEC 220.53)
Motor load addition to other calculated loads (NEC 220.50)
Combining continuous and noncontinuous loads for conductor sizing
Commercial kitchen equipment demand factor concept (NEC Table 220.56)
Household range demand factor concept (NEC Table 220.55)
Multi-occupancy building — summing individual unit loads
Two-family dwelling — applying the optional method per unit
Warehouse general lighting unit load — 0.25 VA per square foot (NEC Table 220.12)
Combining Table 220.12 and Table 220.44 in one building calculation
General-purpose receptacle unit load — 180VA per outlet (NEC 220.14)
Condition for using the optional multifamily method (NEC 220.84)
Why general lighting load is based on floor area, not actual fixture wattage
Sign/outline lighting circuit calculated load — minimum 1200VA (NEC 220.14)
Standard method vs. optional methods — always available vs. conditional
Worked example — combined continuous and noncontinuous feeder load

Tip: Demand factors almost always follow the same shape: 100% of a smaller first chunk, then a lower percentage on everything past that. Learn the break point and the percentage for each table instead of memorizing isolated numbers — the logic transfers across tables.

Questions

45 min

Time

70%

Pass

Timer starts immediately. Progress is auto-saved.