Delmar's Introduction Flashcards
A current of _______ usually causes a slight tingling sensation.
2 to 3 milliamperes
The tingling sensation is very painful at about ______.
20 milliamperes
Currents between ____________ cause muscular paralysis
30 and 40 milliamperes
________ can cause breathing difficulty
40 and 60 milliamperes
Currents from ______________ generally cause death because the heart goes in fibrillation.
100 to 200 milliamperes
The voltage considered to be the most dangerous to work with is _________.
120 volts
Currents from ___________ cause extreme difficulty in breathing.
60 to 100 milliamperes
What does OSHA stand for?
Occupational Safety and Health Administration.W
What year was OSHA created?
1971
What does MSDS stand for?
material safety data sheets
How do you check to make sure a piece of equipment is de-energized before working on it?
- Test the voltmeter on a known energized circuit to make sure the tester is working properly.
- Test the circuit you intend to work on to make sure it is truly de-energized.
- Test the voltmeter on a known energized circuit to make sure that the tester is still working properly.
What does GFCI stand for?
Ground-fault circuit interrupters
How does a GFCI work?
By sensing the amount of current flow on both the ungrounded (hot) and grounded (neutral) conductors supplying power to a device. In theory, the amount of current in the two conductors should be equal but opposite in polarity.
What does AFCI stand for?
Arc-Fault Circuit Interrupter
What is a parallel arc fault?
When two conductors are shorted together
What is a series arc fault?
A fault in series. Usually caused by a loose screw on an outlet terminal.
What is a tamper-resistant receptacle?
Receptacles with a plastic mechanism that cover the outlet openings which will retract and permit entry only when a device with tow blades.
What is the purpose of grounding?
To provide a low resistance path to ground to prevent conductive objects from existing at a high potential.
What are the four classes of fires?
Class A: Wood and paper
Class B: grease, liquids, and gases
Class C: energized electric equipment
Class D: metals
What section with the NEC deals with grounding electrical systems?
NEC 250
What is one of the leading causes of electrical fires?
Poor connections.
What is the most important rule of electrical safety?
Think before you act
Why should a person work with only one hand when possible?
So electrical current will not pass through your chest
What is a ground fault?
When a path to ground other than the intended path is established.
