303 RW-303.2
NEC section 250.4(A)(2) deals with ____.
Grounding electrically conductive materials enclosing electrical circuits
The scope of article 250 covers all of the following topics, except for ___.
Grounding requirements for surge protection
The maximum number of 3 pole circuit breakers used as service disconnects permitted in a three phase panelboard is ____.
1 breaker
During lighting strikes, electrons seek to return to ____.
1 only(ground(earth))
The requirements for grounding equipment in health care facilities are found in article ___.
517
In figure 303.05, the main bonding jumper is shown at point ___.
A.1
In figure 303.05, the grounding electrode conductor is shown at point ___.
B.2
____ is where conductors and metal equipment are connected to establish electrical continuity and conductivity.
Bonding
____ is where conductors and metal equipment are connected together.
Bonding
In figure 303.05, the equipment grounding conductor is shown at point ___.
C.3
Lighting ionizes the air, thus making it good___. This enables electrons to travel from the clouds to the earth.
Conductor
The NEC permits the grounded conductor for a 277 volt circuit to have an insulation color that is ___.
Either gray or white
The purpose of the grounding electrode conductor and the grounding electrode is to establish a ground fault path to open the circuit overcurrent protective device.(Breaker)
False
all NEC grounding requirements are covered in article 250.
False
You are going to build a restaurant on a barge that will float in Galveston bay. Additional code sections that must be considered for this completed installation include ____.
I only(555.37)
You installed the GEC for the purpose of ___.
I only(dissipating overvoltages and reducing shock hazards
An effective ground fault current path has ___.
I, II & III(Continuity, sufficient ampacity, and low impedance)
A 277 volt circuit originates in a 277/480 volt three phase 4 wire panelboard and is installed in EMT without the separate EGC.
II & III only(the metal branch circuit raceway and the system bonding jumper)
Systems are grounded to provide a path for ___.
II only(lightning)
Loose connections in a circuit conductor cause arcing and in turn oxidation occurs at the connection. The circuit is connected to a single load. The voltage at the load will be ____ with the poor connection in the circuit.
Less
Which of the following statements does NOT describe objectionable current?
Neutral current flowing over the neutral conductor
The purpose of connecting the main bonding jumper is to ___.
Provide an effective path for ground fault current
Refer to figure 303.04. The conductors between the transformer and switch 1 are best described as ___ conductors.
Secondary
Refer to figure 303.04(303.1). Without knowing the size of the conductors between wireway and switch #3, which of the following best defines these conductors?
Tap
If a ground fault occurs, the branch circuit OCPD will open most quickly when ___.
The branch circuit is installed in EMT and a separate EGC has been pulled
Although air is a good insulator, ionized air is conductive and helps to sustain arcs when an electrical arc causes the air to be ionized.
True
Because the connection is a fusion of high conductivity, Furseweld connections can withstand repeated fault currents and will not loosen in the way that mechanical connectors can.
True
resistance to earth is also commonly known as resistivity
True
Ionization of the air around an electrical arc can be a problem because the air becomes ___ and can cause the arc to last longer.
a conductor
Loose connections in a circuit conductor cause arcing and in turn oxidation occurs at the connection. This oxidation causes the total circuit resistance to ___.
increase
You connected the GEC to the copper main service pipe above the ceiling. The plumber later disconnected it and has left it disconnected. If a "hot" branch circuit conductor contacts the EGC installed with that circuit, the branch circuit break will ___.
take approximately 2 seconds longer to trip