Switching Operations Flashcards
7 cards from real SOPD practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Switching Operations flashcards as text
When performing a switching operation to isolate a faulted line section, what is the FIRST action a system operator should take?
Answer: Obtain authorization from the Energy Control Center and verify tag-out requirements
Authorization and tag-out verification must precede any switching action to ensure safety and coordination.
A normally-open tie switch between two substations is closed to pick up load from a de-energized feeder. This action is an example of:
Answer: A transfer switching operation
Closing a tie switch to transfer load from one source to another is classified as a transfer switching operation.
During parallel switching, two sources are momentarily connected together. Which condition MUST be verified before paralleling?
Answer: Voltage magnitude, phase angle, and frequency must be within acceptable tolerances
Paralleling without matching voltage, phase angle, and frequency can cause large fault currents and equipment damage.
What does the term 'hot-line order' (or 'clearance') mean in switching operations?
Answer: A written authorization granting a work crew control of a specific circuit or equipment
A clearance (hot-line order) is a formal authorization that transfers control of equipment to a work crew, ensuring the operator does not re-energize it.
Which switching device is designed to interrupt load current but NOT interrupt fault current?
Answer: Air-break disconnect switch
Air-break disconnect switches can open and close under no-load or light conditions but lack fault interrupting capability.
A sectionalizer installed on a distribution feeder counts fault current pulses from the upstream recloser. After a preset number of counts, it opens during a:
Answer: Dead-time interval between recloser operations
Sectionalizers open during the de-energized dead-time interval so they do not interrupt fault current themselves.
When switching out a line segment using the 'open-before-close' method, what is the primary safety benefit compared to 'close-before-open'?
Answer: It prevents a momentary parallel between two sources, eliminating circulating current risk
Open-before-close (make-before-break avoidance) ensures the two sources are never paralleled, preventing circulating currents and potential fault conditions.