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Three of 115 scored questions, the smallest category, covering temporary power, grounding and GFCI protection, and service and distribution coordination with other trades.
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Three questions. The smallest category on the paper, and worth exactly as much per question as any other.
The two subtopics
- Temporary power, grounding and GFCI protection
- Service, distribution and coordination with other trades
What a general contractor is asked
Site safety and coordination, not electrical design. You are not expected to size a service.
What you are expected to know is what makes a site safe and where your responsibility sits relative to the electrical subcontractor's.
GFCI on temporary power
Ground fault circuit interrupter protection, or an assured equipment grounding conductor program, is required for temporary power on construction sites under 29 CFR 1926.404(b)(1).
Note the alternative. It is not GFCI or nothing - the assured grounding program is a permitted substitute, and questions test whether you know a second option exists.
Grounding electrode versus equipment grounding conductor
These terms sound interchangeable, but they do different jobs. A grounding electrode is the conductive object or system in contact with earth. The grounding electrode conductor connects the grounding electrode to the electrical system at the required connection point. An equipment grounding conductor runs with the circuit conductors and bonds exposed, noncurrent-carrying metal parts so a fault has a continuous path back to the source.
| Part | Main purpose | Construction-site takeaway |
|---|---|---|
| Grounding electrode | Connects the system to earth | It is part of the grounding electrode system, not the normal fault-current return path for cord-connected tools. |
| Grounding electrode conductor | Connects the grounding electrode to the grounded system at the prescribed point | OSHA §1926.404(f)(5) specifies where the connections are made for grounded and ungrounded systems. |
| Equipment grounding conductor | Provides the equipment bonding and fault-current path | Keep it continuous and correctly connected; the assured equipment grounding program requires continuity and correct-attachment tests. |
| Grounded circuit conductor | Normally carries current as part of the circuit | Do not confuse it with the equipment grounding conductor; OSHA requires them to be identifiable and distinguishable. |
For a grounded system, OSHA requires the grounding electrode conductor to connect both the equipment grounding conductor and grounded circuit conductor to the grounding electrode. The connections belong on the supply side of the service disconnecting means, or at the corresponding supply-side point for a separately derived system. The general contractor exam tests the purpose and coordination concepts; conductor sizing and installation details belong to the electrical design and code work.
Earth connection and equipment fault path are not synonyms. Do not assume a ground rod alone makes damaged cord-and-plug equipment safe. OSHA treats grounding, GFCI protection, and the assured equipment grounding conductor program as related but distinct requirements.
10 feet minimum from energized lines up to 50 kilovolts for general work, and 20 feet as the default during crane assembly under Subpart CC. Two different numbers for two different activities, both in the OSHA standards.
Lockout and tagging
Required before work on de-energized equipment, at 29 CFR 1926.417. The principle is that de-energized is not the same as safe until it is locked out and verified.
How much to prepare
Lightly. Three questions does not justify heavy tabbing, and the material overlaps with General Requirements anyway. Know where in the OSHA standards to look.
Common questions
How many electrical questions are on the NASCLA exam?
3 of the 115 scored questions, the smallest category.
What is required for temporary power?
GFCI protection or an assured equipment grounding conductor program, under 29 CFR 1926.404(b)(1).
What is the difference between a grounding electrode and an equipment grounding conductor?
The electrode connects the system to earth; the equipment grounding conductor bonds exposed metal equipment and provides the equipment fault path. They are distinct parts of the grounding system.
What clearance is required from power lines?
10 feet minimum for lines up to 50 kilovolts for general work, and 20 feet as the default during crane assembly.
What does lockout require?
Locking and tagging circuits before work on de-energized equipment, under 29 CFR 1926.417.
How much should I study this category?
Lightly. Three questions, and the material overlaps with General Requirements.