SOPD Switching Operations 3

Question 1

A switching order requires opening a 138 kV disconnect switch while the associated breaker is still closed. This is considered:

Accepted Answer

A serious procedural violation that could destroy the switch

Answer

Opening a disconnect switch under load creates a sustained arc that can destroy the switch and create a dangerous fault.

Question 2

The 'three-phase dead check' before re-energizing a line requires verifying absence of voltage on:

Accepted Answer

All three phases using a calibrated voltage-measuring device

Answer

All three phases must be checked individually because a single-phase conductor could remain energized through backfeed.

Question 3

A 'phantom load' condition on a distribution circuit can occur after switching when:

Accepted Answer

Capacitor banks remain connected and supply reactive power to the de-energized line

Answer

Capacitor banks can keep a de-energized line segment at near-normal voltage through resonant backfeed, creating a phantom load reading.

Question 4

In the context of switching operations, what is 'clearance stacking'?

Accepted Answer

Issuing multiple clearances on the same equipment to different work crews simultaneously

Answer

Clearance stacking — issuing overlapping clearances on the same device — is a dangerous practice that can lead to one crew unknowingly re-energizing another crew's work zone.

Question 5

When reconfiguring a substation bus arrangement, the operator must verify ground switches are open before energizing because:

Accepted Answer

Ground switches create a three-phase bolted fault if closed on an energized bus

Answer

Energizing a bus with a ground switch closed creates a bolted three-phase fault, resulting in catastrophic damage and potential injury.

(SOPD) System Operator/Power Dispatching Practice Test

(SOPD) System Operator/Power Dispatching Practice Test

SOPD Switching Operations 3