MO VALLEY 2-5 QUESTIONS AND ANSWERS
The NEC's definition of medium voltage ranges from ? to ? .
a.
2,001 V / 35,000 V
b.
4,160 V / 42,000 V
c.
7,200 V / 66,000 V
d.
12,470 V / 69,000 V - Answers -a.
2,001 V / 35,000 V
From a technical standpoint, heating conditions that influence the choice of cable
include the ambient temperature, the proximity of other cables, adjacent heat sources,
and the thermal conductivity of the soil it will be buried in.
T/F - Answers -True
The purpose of applying strand shielding between the conductor and the insulation of
the cable is to eliminate ? in air voids at the interstices between the conductor and the
cable insulation.
a.
carbon buildup
b.
heat
c.
voltage stress
d.
water - Answers -c.
voltage stress
,? insulation offers excellent resistance to ozone and weathering and has good low
temperature properties, good heat resistant properties, and excellent electrical
properties.
a.
EP
b.
PILC
c.
Thermoplastic
d.
XLP - Answers -a.
EP
On cable circuits where the clearing time requirements of the 100% level category
cannot be met and there is adequate assurance the faulted section will be deenergized
in a time not exceeding one hour, cable with a ? insulation level should be used.
a.
85%
b.
133%
c.
173%
d.
225% - Answers -b.
133%
Insulation shielding of medium voltage cable helps to prevent high stress and ? by
distributing the stress evenly throughout the entire insulation structure.
a.
EMF pulses
b.
possible corona
, c.
radio noise
d.
treeing - Answers -b.
possible corona
When moisture fills the very fine electric stress lines that occur at voids and other
insulation irregularities on a cable and spread towards the outer edge, it is known as ? .
a.
current stress breakdown
b.
sharp bending damage
c.
static discharge damage
d.
water treeing of the insulation - Answers -d.
water treeing of the insulation
Rubber gloves shall be worn continuously while working on any structure carrying live
conductors. This is known as the ? rule.
a.
assured safety
b.
ground to ground
c.
safety assurance
d.
zero potential - Answers -b.
ground to ground
Rubber gloves shall be worn when a vault or cabinet with a live cable is opened and
shall be worn continuously until the vault or cabinet is locked. This is known as the ?
rule.
a.
cableman's
The NEC's definition of medium voltage ranges from ? to ? .
a.
2,001 V / 35,000 V
b.
4,160 V / 42,000 V
c.
7,200 V / 66,000 V
d.
12,470 V / 69,000 V - Answers -a.
2,001 V / 35,000 V
From a technical standpoint, heating conditions that influence the choice of cable
include the ambient temperature, the proximity of other cables, adjacent heat sources,
and the thermal conductivity of the soil it will be buried in.
T/F - Answers -True
The purpose of applying strand shielding between the conductor and the insulation of
the cable is to eliminate ? in air voids at the interstices between the conductor and the
cable insulation.
a.
carbon buildup
b.
heat
c.
voltage stress
d.
water - Answers -c.
voltage stress
,? insulation offers excellent resistance to ozone and weathering and has good low
temperature properties, good heat resistant properties, and excellent electrical
properties.
a.
EP
b.
PILC
c.
Thermoplastic
d.
XLP - Answers -a.
EP
On cable circuits where the clearing time requirements of the 100% level category
cannot be met and there is adequate assurance the faulted section will be deenergized
in a time not exceeding one hour, cable with a ? insulation level should be used.
a.
85%
b.
133%
c.
173%
d.
225% - Answers -b.
133%
Insulation shielding of medium voltage cable helps to prevent high stress and ? by
distributing the stress evenly throughout the entire insulation structure.
a.
EMF pulses
b.
possible corona
, c.
radio noise
d.
treeing - Answers -b.
possible corona
When moisture fills the very fine electric stress lines that occur at voids and other
insulation irregularities on a cable and spread towards the outer edge, it is known as ? .
a.
current stress breakdown
b.
sharp bending damage
c.
static discharge damage
d.
water treeing of the insulation - Answers -d.
water treeing of the insulation
Rubber gloves shall be worn continuously while working on any structure carrying live
conductors. This is known as the ? rule.
a.
assured safety
b.
ground to ground
c.
safety assurance
d.
zero potential - Answers -b.
ground to ground
Rubber gloves shall be worn when a vault or cabinet with a live cable is opened and
shall be worn continuously until the vault or cabinet is locked. This is known as the ?
rule.
a.
cableman's
