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NCCER Electrical Level 2 Module 9 'Grounding and
Bonding'
1.
NEC Article 250
.: is the primary governing article
for the
proper
use and
installation
of grounding and bounding.
2.
Suppose a loose connection has been exposed bare conductor
and it con- tacts the edge of a metal enclosure. Is this an example
of a short circuit or a
ground fault?: ground fault
3.
A single-phase system has two legs, Leg A and Leg B. If Leg A is
carrying 50A and Leg B is carrying 45A, the current carried by the
neutral is
.: 50A-45A=5A
(Leg A- Leg B)
4. Assuming the use of 75 degrees Celsius copper conductors, a 200A
commer-
cial services would require?: 3/0 service conductors
5. A
ground rod must be installed in a coastal location and can only be
driven halfway before encountering a rock shelf. One alternative is to
.: burry the
rod in a trench at least 30" (750 mm) deep
6.
The EGC for a flexible metal conduit connection to a
motor supplied with a 20A circuit
.: 12 AWG copper
7. When using nonmetallic boxes with type NM cable, the grounding
wire
.:
is
not
required
to
be
connected
to
the
box
8.
When grounding at more than one building, the
GEC at the second building is sized using
.:
NEC Table 250.66
9.
If the voltage
drop between a grounding electrode and an auxiliary potential
electrode is 10V and a current of 10A is passed between an
auxiliary current
electrode and the grounding electrode, the
resistance is .: 1 ohm
10. When completing a three-point test, the potential electrode is
placed at
