2nd test Flashcards
when is energized work permitted
When de-energizing would interrupt essential life support, emergency alarms or ventilation systems.
voltage testing,troubleshooting, or under 50V AC/DC
when is energized work not permitted
because it needs to get done faster
what forms of energy can be released during an arcing fault event
heat, pressure, sound light, sound,gas
True or false
the energy released during an arcing fault is directly related to the amount of energy available and how long it is available
true
employers must comply with the general duty clause of the osha act which is generally sited when no specific standard applies to the hazard it is found in section ___ of the osha act
3
4
5
7
9
5
NFPA 70 -120.5
Process for Establishing and Verifying an Electrically Safe Work Condition.
True or False
electrical conductors and circuit parts shall not be considered to be in an electrically safe working condition until all requirements article 120 have been met
True
the point-to-point method has equations to calculate the available fault current ____.
a. at the end of a run of conductor or busway
b. at the secondary of a transformer assuming infinate primary available fault current( this is a conservative calculation)
c. at the secondary of a transformer with the primary fault current known
d. all of the above
D
it is less likely the workers, contractors, and facility owners would allow energized work if everyone involved in the decision-making process fully understood the laws requirements hazards true cost and consequences associated with the ____.
a.LOTO program
b.energized work’
c.company policy
d.NFPA 70E
e.union
b
A utility replaces an existing 300 kVA transformer with the 500 kVA transformer having the same percent impedance. The available fault current on the secondary of the new transformer will be _____ the available fault current of the transformer being replaced.
a.higher than
b.lower than
c.the same as
A
Too often a culture exists in the workplace or workers are routinely allowed expected to work on and near energized electrical circuits this could be due to which of the following?
I-Application of best practices
II-failure to realize how quickly a situation might change and cause an energy release.
III-ignorance of laws.
IV-lack of knowledge of the severity of hazards
a. I
b. I,II
c.I,II,III,IV
d.II,III,IV
d
In electrical he safe work condition is defined in ___.
a.nfpa 70e article 100
b.osha requirments
c.NEC
d.NECA 1
e. All of the above
A
OSHA requires employers to furnish each employee with a place of employment free of ______ hazards that are causing or are likely to cause death or serious physical harm.
a.most
b.any
c.predictable
d.severe
e.recognized
e
______Is/are the most prevailant consequences of electrical incidents. These injuries can be due to either electrical shock hazard or arc flash hazards
a.Burns
b.hearing loss
c.slips
d.falls
e.sight loss
A
extensive test and analysis by industry members have shown that the energy released during a arcing fault is related primarily to what characteristics of the OCPD protecting the affected circuit.
a. The time it takes the OCPD to open and the amount of fault current the OCPD lets through
b. The ampacity of the OCPD and the voltage rating of the OCPD.
c.A and B
d.Neither A or B
e.all of the above
A
