Quiz 3 - Commercial Wiring - Unit 2 Flashcards
Figure 2-3 is indicating
26-240(2) - the enclosure must be locked
12-012 - rules for underground conductors in conduit
6-300(3) - an underground entrance to a building must be sealed
All of the above
Figure 2-4 is indicating,
A busway (bus duct) is connecting the utility transformer to the main switch
A busway (bus duct) is connecting the utility transformer to the secondary switches
A busway (bus duct) is connected underground
Transformers use liquids (oil/synthetic) to reduce heat at the core of the transformer.
True
False
Oils containing PCB’s require a safe steps for disposal.
True
False
Dry-type transformers are cooled by open air flow and/or fans.
True
False
Figure 2-6 is indicating a basic transformer connection between the high voltage primary and the distribution.
True
False
Figure 2-9 is indicating,
A system that is grounded at the first point of distribution (secondary)
A 3 phase primary 600V to secondary 208/120V transformer connection
Primary feed is Delta configured and the Secondary is Wye configured
All of the above
Figure 2-11 is indicating
A neutral is achieved by grounding the coil of a transformer
The neutral is grounded on the secondary
The neutral is grounded on the primary
Both A and B
Figure 2-12 is indicating
The primary side is expressed as H1, H2
The secondary side is expressed as X1, X2
The primary and secondary are both Delta configurations
All of the above
The most commonly used system for modern commercial buildings is the 3 phase, 4-wire wye system.
True
False
Figure 2-14 is indicating,
Potential and Current transformers are connected around the high-voltage section of a substation
Watt-hour and Varhour meters are monitoring a delta configured autotransformer
The high voltage line feed is 4160V
All of the above
Figure 2-16 is indicating,
A 1,200A 3 phase main
All sections of the switchboard must be bonded together
Bonding must be in accordance with 10-616
A #6 AWG is connected to the water main
Three 4” conduits containing 750MCM conductors are feeding the service
All of the above
Table 2-3 is showing an underground configuration for conductors in raceways according to T-D11.
True
False
Figure 2-16 and 2-17 are two images of the same service equipment.
True
False
Grounding isn’t used for saving lives and protecting equipment.
True
False
Grounding helps to,
Minimize voltage spikes
Stabilize voltage to ground
Provide a low impedance path to ground
All of the above
Ground-fault damage is determined by the overcurrent device response time and the amount of fault current.
True
False
Figure 2-20 is indicating,
The metal water pipe is used as a grounding electrode
The gas pipe and hot water pipe are bonded to ground
Service neutral is considered a grounded conductor
A bond bushing is connected to the service raceway
A bonding jumper is installed around the water meter
All of the above
Figure 2-21 is showing how all parts being bonded together is known as ‘system grounding’
Question 19 options:
True
False
Equipotentiality means conductive parts are at a substantially equal electric potential
True
False
Exposed, non current carrying parts of a system must be bonded together according to section 10.
True
False
Conductors used for grounding must be either protected or resistant to corrosive conditions.
True
False
Figure 2-22 is indicating,
A concrete-encased electrode
A rod electrode
A plate electrode
All of the above
Figure 2-23 is a ground bushing used at the end of raceways at a point of connection. This bushing requires a ground connected under the attached lug.
True
False
Grounding the secondary side of a wye connected transformer will establish a new service.
True
False
Figure 2-31 is indicating two different types of ground bushing interconnection. One is looped using one conductor between conduits, the other has separate bonding conductors for each conduit.
True
False
Ground fault protection is provided on the line side of the service disconnecting means.
Question 27 options:
True
False
Ground Fault Protection circuit devices,
Were developed to detect high voltage fault currents
Were developed to detect low value phase to ground arcing
Were developed to detect low value ground to bond arcing
An arc fault that generates 600 amps may still be allowed to flow through (not trip) an overcurrent device rated for 1600 amps.
True
False
GFP monitors sense phase to phase faults.
True
False
GFP’s and GFCI’s are the same.
True
False
The electrician can minimize the possibility of an arc by,
Ensuring conduit couplings and fittings are installed properly
Ensure conductor insulation isn’t damaged
Installing insulating bushings on all raceways
Properly grounding and bonding the electrical system
Ensuring all electrical connections are tight.
All of the above
The electrician shouldn’t work on live panels because they could end up being the path to ground for a fault current.
True
False
