Cable fault locating questions

[adamwilson]

The main objective of cable fault location is to _____________.

a. Identify the cause of the fault
b. Identify which circuit to de-energize
c. Identify where to pull new cable
d. Reduce the cost of down time of service

Could use help with this question.

[adamwilson]

In the thumper method of cable fault location, the fault is pinpointed at _________.

a. the point of the earth movement
b. the power cable termination
c. the point where static waves are emitted
d. where the high voltage surge arcs over and makes a loud noise

Also need help with this question.

[a.lallana@epsii.com]

In the thumper method of cable fault location, the fault is pinpointed at _________.

a. the point of the earth movement
b. the power cable termination
c. the point where static waves are emitted
d. where the high voltage surge arcs over and makes a loud noise

Also need help with this question.


Capacitor Discharge Systems more commonly know as a Thumpers is used for underground cable faults. it generates a capacitive charge at the voltage that you select and then discharges it at a predetermined rate. once "Thumping" you will be able to hear the arc at the point of fault. Usually you need to use a listening device in order to hear it, although it is possible to hear the fault with out it if you are standing directly over the ground where the fault is and its not to deep.

Becuase the Thumper in its self is a destructive method to locating cable It is strongly recommended that you first trace the cable using a cable tracer then use a TDR (Time domain reflectometer) to find the approximate location of the fault and then proceed with the thumper now having a general idea of where the fault is and reducing the damage to the cable and preventing damage to the nearby phases.

So going back to the question i would answer with "D"

[adamwilson]

Hey, thanks that was a very helpful explanation! What's your opinion about this one:

The main objective of cable fault location is to _____________.

a. Identify the cause of the fault
b. Identify which circuit to de-energize
c. Identify where to pull new cable
d. Reduce the cost of down time of service

I'm stuck between A and C but leaning toward "identify where to pull new cable." This seems to be the only reason why we ever use the thumper. What good comes from knowing the cause of the fault?

[a.lallana@epsii.com]

Hey, thanks that was a very helpful explanation! What's your opinion about this one:

The main objective of cable fault location is to _____________.

a. Identify the cause of the fault
b. Identify which circuit to de-energize
c. Identify where to pull new cable
d. Reduce the cost of down time of service

I'm stuck between A and C but leaning toward "identify where to pull new cable." This seems to be the only reason why we ever use the thumper. What good comes from knowing the cause of the fault?

My answer would be c, the main objective of cable fault is to locate where the actual fault occured in order to repair the damaged cable. Where the fault occured does not tell us what was the cause of the fault, it just told us what point had the weakest insulation on that circuit. Hope that helps you.