Insulator thickness for high voltage power lines should be based on ______ voltage
Peak
Maximum acceptable ASTM D974 on new transformer oil is
... [Show More] ______
.015
Minimum IR for 480 gen with random wound stator coils manuf in 1995
5 megohms
Bimetallic strips in thermal relays have two metal strips with a different
Coefficient of expansion
AC dielectric withstand Maintenance of 5 kV dry transformer should not exceed _____% of factory voltage for one minute
65
Lead acid storage batteries do Not include which hazard?
High voltage arcing
High resistance connections in DC armatures are best identified by
Trending
Air terminals for lightning protection that exceed 24" shall be supported at not less than _____ their height
1/2
Most low voltage circuit breaker manufacturers recommend that contacts touch within _____" of each other
1/8
Circular mil area =
D squared
What would cause low specific gravity in a battery
Low charge voltage
D1816 1mm gap
34kV
Locked rotor kva
HP x max code value
Locked rotor current
Locked rotor kVA/(1.732 x kV)
A moving iron meter operates by applying ____ current to the coil
AC
Arcing fault relative to bolted fault is _____%
80
a . b=
|a| x |b| x cosine theta
Which test is an acceptable alternative to PF on transformer bushings?
NBDFR
The easiest method for determining contact sequence on a low voltage cb is
Light circuit
Trip current supervision is a metering parameter of an IED True or False
False
IEC61850 has roots in RTU while DNP3 has roots in LAN/WAN true or false
False
The generally accepted deviation from nominal 60hz is _____hz
.5
A ______requires very little energy to be activated
Shunt reactor
In a wye connected system without neutral grounding, zero sequence currents are
Zero
True/false: Fuse resistance is a required maintenance test for low voltage starters with fused protection
False
Resistance grounding is used for voltages
3.3kV-11kV
T/F: FR3 is not recommended for use with conservators without a bag
True
For additional branch circuits for other utilization equipment, the Overcurrent device must be located
In the elevator/control/machine room
ATS fr3 for water content max ______ ppm
25
Which contact has the highest melting point
Tungsten
True/false: an arc flash hazard assessment will determine if lockout is required
False
True/false: testing legally required standby during max load should be avoided to not tax the system
False
T/F natural esters have a higher PF than mineral oil
True
Plate electrodes for grounding shall not expose less than _____feet to exterior soil
2
At what iec 61850 level would you find instrument transformers and circuit breakers
Process
At what iec 61850 level would you find protection and control devices
Bay
Harmonic analyzers use which method to identify predominant harmonic components?
Frequency domain analysis
A concrete encased electrode shall consist of at least _____meters of bare copper not smaller than _____AWG
6 4
A disadvantage of_________ is that third order harmonics circulate between neutrals
Solid grounding
The purpose of a commutator on a dc motor is to
Maintain proper direction of current flow in the armature
What is required when maintenance testing natural ester fluid
Color
According to NETA, analog test equipment should be calibrated in accordance with which frequency schedule: _______ months
12
What is the maximum acceptable value for Mineral Oil found in service-aged SF6 gas? Ppm
10
High-voltage oil circuit breaker power factor results should be within ____ %of nameplate rating for in service bushings per NETA standards.
10
When testing power factor of transformer bushings, NETA-ATS recommends investigating power-factor and capacitance readings that vary from nameplate values. What is the tolerance allowed? %
5
Harmonics cause which of the following:
All of the above
which one of the following would require to be protected against overcurrent in accordance with its ampacity?
Service conductors
In an alternator, when the rotor DC excitation current is removed there is a possibility of damaging high voltages being developed. In order to limit voltage and thereby prevent damage, a _____ or a diode can be included in the circuit.
Field discharge resistor
Sphere gaps are used for:
All of the above
What is the tolerance allowed from the nameplate value when power factor testing new liquid-filled transformer bushings? %
50
What action level would apply to a Delta T of 15C between component and ambient air?
Repair as time permits
What is the minimum acceptable dielectric breakdown value for service-aged FR3 insulating liquid tested in accordance with ASTM D1816 using a 1mm gap?
34kV
Which of the following maintenance tests is required for a 13200-480Y/277V 2500kVA dry-type transformer?
Excitation at designated tap
Which Subpart of OSHA 29 CFR 1910 addresses electrical safety?
S
True/false ASTM D 924 is a required acceptance test for liquid-filled transformers with natural ester insulating fluid per NETA standards.
False
Which of the following best describes the arc inside of a vacuum circuit breaker?
Metal vapor
Which of the following features/accessories is LEAST likely to be found on an automatic transfer switch installation?
Current balance relay [Show Less]