Electricity level 3 section 6
The resistance of switchgear should be checked using a
1,000V megger
What is a standard output voltage of potential transformers?
120V
When performing themographic surveys, a major deficiency is indicated by a gradient of
16 deg C
Wires from a sensor to a ground fault relay should be no longer than
25ft
Which of the following abbreviations is used on electrical drawings to represent an oscilloscope?
CRO
Which of the following tests is conducted in order to detect loose connections?
Heat scanning test
The three sections of switchgear enclosures are the front section, the bus section, and the
cable or termination section
Field marking of service equipment shall include the
date fault current calculations performed
According the the NEC, neutral conductors size No. 6 and smaller must have a continuous marking of white or
gray
The voltages and currents used in the primary circuits of substations are reduced to usable levels by
instrument transformers
Nonstandard abbreviations on electrical prints will typically be defined on the
legend
Which of the following is a current transformer?
oil-filled
Circuit breaker ratings are given
on the breaker nameplate
A downed power line is most likely to result in a(an)
phase failure
The basic purpose of switchgear is to
provide power system protection by automatically isolating faulty components
The continuous current that a circuit breaker can carry without exceeding a standard temperature rise is known as the
rated current
The most important consideration for selecting a current transformer for relaying is the
saturation characteristics
Connection diagrams should be used to
show the internal wiring connections between the parts that make up an apparatus
The maximum 60Hz voltage that can be applied to a switch for one minute without causing insulation failure is known as the
withstand rating
The three basic methods of sensing ground faults are ground-return, residual, and
zero sequence