Westinghouse, Applied Protective Relaying Flashcards
The device designation 52Y indicates the device is a:
Circuit breaker anti-pump auxiliary.
The accepted industry standard for showing relay contacts on circuit diagrams is to show the contacts in the position they assume when the relay is:
De-energized
Protective relay zones of protection are overlapped to:
Avoid leaving unprotected areas.
A high speed relay is defined as a relay that has an operating time which does not exceed:
3-5 cycles.
Open circuits on power systems occur more frequently than short circuit faults?
False.
The circuit diagram usually gives the following three items of information about currents and voltages: location, direction, and polarity. It does not include:
Magnitude.
In a potential transformer the voltage drop from the polarity to the non-polarity marked terminals on the primary side is substantially in phase with the voltage drop from the polarity to the non-polarity marked terminals on the secondary side.
True.
A high current arc (in excess of 100 amperes) in air has a nearly constant drop of around ________ volts per foot.
400
The ground and the neutral point on a three phase system are by definition the same point.
False.
The current flowing out at the polarity marked terminal on the secondary side of a current transformer is substantially in phase with the current flowing in at the polarity marked side or terminal on the primary.
True.
The term Symmetrical Components refers to a mathematical method of reducing any unbalanced three phase set of vectors into three ____________ systems.
Balanced
A well designed protective relay system should provide three basic operational characteristics. What are they?
Reliability
Selectivity
Speed
