Load Calculations for Master Electrician Exams
Article 220 load calculations as tested on master exams: dwelling units by the standard and optional methods, multifamily, commercial and industrial loads.
MELU-102 12 lessons · 5 h 16 min ▶ Video lessons coming soon
Offered by HSM University · Master Electrician and Contractor Exam Prep (US)
What you'll learn
- Apply Ohm's law, the power formulas and power factor to find current, voltage, resistance and power, using the nominal voltages and rounding rule of 220.5.
- Calculate single-phase and three-phase currents on 120/240 V, 208Y/120 V and 480Y/277 V systems, including single-phase loads on three-phase panels.
- Size branch circuits for continuous and noncontinuous loads and assign outlet loads under 210.19, 210.20, 210.23, 220.14 and 220.18.
- Calculate a dwelling's feeder or service load by the standard method of Part III of Article 220.
- Calculate a single dwelling's load by the optional method of 220.82 and compare it with the standard method.
- Calculate multifamily building loads by the standard method and by the optional method of 220.84, including house loads and unit feeders.
- Calculate nondwelling feeder loads with Table 220.12 unit loads, continuous load factors, the receptacle demand factor of 220.44, show windows, signs and motors.
- Apply the special rules for commercial kitchens (220.56), new restaurants (220.88), schools (220.86) and farms (220.102 and 220.103).
- Turn a calculated load into an overcurrent device and conductor using 215.2, 230.42, 240.4, 240.6, 110.14(C) and ampacity correction and adjustment.
- Calculate feeder and service neutral loads under 220.61, including the permitted and prohibited reductions.
- Determine whether an existing service can carry added loads using 220.87, 220.83 and energy management provisions.
- Work mixed load calculation problems accurately under exam time limits, citing the code by section number without relying on reproduced text.
Course content
12 lessons · 5 h 16 min total · final exam
- 1 Exam math refresher: Ohm's law and power 29 min · quiz
- 2 Single-phase and three-phase calculations 28 min · quiz
- 3 Branch circuit calculations 29 min · quiz
- 4 The standard method for dwelling units 20 min · quiz
- 5 The optional method for dwelling units 23 min · quiz
- 6 Multifamily dwelling calculations 27 min · quiz
- 7 Commercial occupancy calculations 29 min · quiz
- 8 Restaurants, schools and farms 29 min · quiz
- 9 Feeder and service sizing 26 min · quiz
- 10 Neutral load calculations 24 min · quiz
- 11 Existing installations and added loads 25 min · quiz
- 12 Mixed load calculation practice set 27 min · quiz
- E Final exam 20 questions
Requirements
Recommended background. You can start any course at any time.
Description
Article 220 load calculations as tested on master exams: dwelling units by the standard and optional methods, multifamily, commercial and industrial loads.