SOPD Switching Operations 5

Question 1

An operator is performing a live-line switching operation and loses radio communication with the field crew mid-sequence. The correct action is to:

Accepted Answer

Halt all further switching steps until reliable communication is re-established

Answer

Communication loss requires suspending the switching sequence because coordination with field crews is essential for safety and situational awareness.

Question 2

In a ring bus substation, a single breaker failure results in:

Accepted Answer

Loss of only the two lines connected on either side of the failed breaker

Answer

In a ring bus, each breaker is shared between two adjacent elements; one breaker failure requires opening the adjacent breakers, disconnecting only those two elements.

Question 3

The primary reason for tagging (flagging) a switch or breaker during a switching operation is to:

Accepted Answer

Provide a visual warning that the device must not be operated without specific authorization

Answer

Tags provide a critical visual warning preventing inadvertent operation of a device that has been intentionally placed in a specific state for safety or operational reasons.

Question 4

A '2-out-of-3' protection scheme on a transmission line uses three current transformers and trips when:

Accepted Answer

At least two of the three CT inputs indicate fault conditions simultaneously

Answer

A 2-out-of-3 voting scheme requires at least two elements to agree before issuing a trip, reducing false trips from a single CT malfunction.

Question 5

During an emergency switching operation at night, an operator cannot visually confirm the position of a manual disconnect switch in the field. The BEST practice is to:

Accepted Answer

Request the field technician to physically verify and verbally confirm the switch position

Answer

Physical verification by a qualified person on-site, followed by verbal confirmation to the operator, is the safest method when visual confirmation is not possible remotely.

(SOPD) System Operator/Power Dispatching Practice Test

(SOPD) System Operator/Power Dispatching Practice Test

SOPD Switching Operations 5