Topic 9, Bonding and Grounding (Earthing) Flashcards
As a guide, the MAXIMUM recommended DC current value on any bonded conductor should be less than:
A. 250 milliamps
B. 500 milliamps
C. 750 milliamps
D. 1 amp
E. 1.25 amps
B. 500 milliamps
Surge currents due to lightning and other sources MUST be ________ before they penetrate the infrastructure.
A. Shorted
B. Maximized
C. Terminated
D. Equalized
D. Equalized
The impedance of the equipment grounding conductor can only be accurately measured with an instrument known as a(n):
A. Volt ohm meter
B. Power distribution unit
C. Exothermic weld connection
D. Ground impedance tester
E. Amp calculator
D. Ground impedance tester
Often associated with raised flooring, a(n) ________ may consist of copper straps taped to the concrete floor, or it may be the floor itself with the stringers that support the tiles acting as the bonding conductor across the gradient of the floor.
A. Grounding electrode conductor (GEC)
B. Electrical ground bar (EGB)
C. Signal reference grid (SRG)
D. Telecommunications bonding backbone (TBB)
E. Drain wire
C. Signal reference grid (SRG)
You are designing a telecommunications grounding system for a telecommunications room
(TR). The TMGB is located 15 m (50 ft) from the telecommunications rack. What is the
MINIMUM AWG of the ground conductor required?
A. Two
B. Three
C. Four
D. Six
E. Eight
D. Six
The MINIMUM dimensions of the telecommunications main grounding busbar is ________ and variable in length.
A. 4 mm (0.16 in) x 80 mm (3.15 in)
B. 6.3 mm (0.25 in) x 100 mm (4 in)
C. 8 mm (0.31 in) x 110 mm (4.33 in)
D. 10.5 mm (0.41 in) x 140 mm (5.51 in)
E. 12.75 mm (0.50 in) x 175 mm (6.89 in)
B. 6.3 mm (0.25 in) x 100 mm (4 in)
Which of the following is NOT provided by the ac grounding electrode system?
A. Zero volt reference for AC power
B. A path for dissipating electrical current
C. A path for dissipating electrostatic discharge
D. Adequate electrical protection for people and equipment
D. Adequate electrical protection for people and equipment
The recommended MAXIMUM value for the bonding resistance between the nearest available grounding electrode and the busbar in an entrance facility (EF) is ________ ohms.
A. 0.1
B. 0.5
C. 1
D. 2
E. 5
A. 0.1
Based on documentation contained within the Insulated Cable Engineers Association
(ICEA) standard P32-382, Short Circuit Characteristics of Insulated Cable, a copper conductor is capable of safely carrying one ampere for ________ second(s) for every 42.25 circular mils.
A. One
B. Five
C. Twelve
D. Twenty
E. Thirty
B. Five
Electrical power cables are usually routed above aerial cable in order to:
A. Provide aesthetics, as the power cables are bigger than the aerial cables
B. Be a strength member in case a tree or something heavy falls on the lines
C. Negate the need for protectors
D. Intercept and divert direct power strikes
D. Intercept and divert direct power strikes
An isolated ground receptacle may be identified by:
A. Beige coloring with an orange triangle on the face
B. The letters IG
C. Continuous orange coloring
D. Its proximity to the PDU
E. Either A or C
E. Either A(Beige coloring with an orange triangle on the face) or C(Continuous orange coloring)
Which of the following covers lightning protection systems and defines as exposed anything above ground and outside the zone of protection?
A. NTSB-12
B. IEEE 1100
C. NFPA 780
D. NEC 47
E. ANSI J/STD-607-A
C. NFPA 780
As a guide, the recommended maximum AC current value on any bonding conductor should be less than ________ amperes.
A. 0.50
B. 1
C. 5
D. 10
E. 20
B. 1
Certain systems must exist relative to bonding and grounding at every site. Which of the following is NOT one such system?
A. AC grounding electrode system (e.g., in some countries it may also be known as the earthing system)
B. Telecommunications bonding infrastructure
C. Lightning protection system -
D. Equipment grounding system (e.g., in some countries it may also be known as the equipment bonding system)
C. Lightning protection system -
