Services & DistributionQuestion 99 of 521
Where the grounding electrode conductor connects to a concrete-encased electrode, that portion of the conductor is not required to be larger than:
a.6 AWG copper
b.8 AWG copper
c.2 AWG copper
d.4 AWG copper
Explanation
Per 250.66(B), the grounding electrode conductor to a concrete-encased electrode is not required to be larger than 4 AWG copper. 6 AWG applies to a rod/pipe/plate electrode under 250.66(A), and the other sizes are not the code cap for this connection.
Law Reference: 2023 NEC §250.66Practice all 521 questions free — no signup required.
Related questions on this topic
- Where a service has two to six service disconnects for a single service, they must be:
- The minimum depth of working space in front of a 208Y/120 V panelboard (0-150 V to ground, Condition 1: exposed live parts on one side, no live or grounded parts on the other) is:
- When a panelboard is used as service equipment, the main bonding jumper must be:
- Where the grounding electrode conductor connects to a made rod, pipe, or plate electrode, that portion of the conductor is not required to be larger than:
- For a feeder/service neutral, the portion of the maximum unbalanced load that exceeds 200 A may generally be calculated at:
- A 75 kVA, 208Y/120 V transformer has an impedance of 2%. Using the infinite-bus (worst-case) method, the approximate available fault current at the transformer secondary is about:
Last reviewed: · editorial process
PrepPass Editorial Team · Verified against California CSLB C-10 Electrical Trade Examination · How we review