ANSWERS (GRADED A+)
Do you know the primary reason for grounding? - ANSWER-Equipment grounding limits
the voltage between all metal parts of the system and earth ground to a safe level,
thereby reducing the risk of shock.
Can you name the common standards associated with electrical control? - ANSWER-
National Electrical Code (NEC)
National Electrical Manufacturer's Association (NEMA)
International Electrotechnical Commission (IEC)
Underwriter's Laboratories (UL)
Occupational Safety and Health Administration (OSHA)
Can you state the ten basic rules of electrical safety? - ANSWER--Remove all metal
jewelry
-Be aware of conditions before working on a piece of equipment
-Do not rely on safety devices to protect you
-Never remove the grounding prong on an AC plug
-Always keep your tools and test equipment organized
-Do not work on wet floors
-Work with one hand
-Always move slowly and deliberately
-Do not work alone
-Avoid distractions
Can you explain the operation of three-phase power? - ANSWER-Three-phase power is
electrical transmitted in three separate phases. An alternator that has three main
windings operating 120 degrees apart creates the three phases.
Do you know the function of neutral in electrical power? - ANSWER-A neutral is a
conductor that provides a common return path to the source for the conductors in a
system.
Can you explain the operation of grounded and ungrounded systems? - ANSWER-The
difference between the operation of a grounded system and an ungrounded system is
seen in their reactions to a ground fault. A ground fault occurs when one of the phases
becomes grounded.
If the ground fault occurs on one of the phases pf a grounded system, the circuit
protection devices will open the circuit because of the circuit because of the increased
current draw. This will cause the power to shut down.
If a ground fault occurs in one of the phases of an ungrounded system, the operation of
the circuit will not be interrupted.