Exam for Continuing Education Units 1.5 learning units (0.15 CEUs)

Fundamentals and Fine Points of Circuit Protection for PV and Mission Critical Systems

Thursday, September 29, 2011 at 2 p.m. ET/1 p.m. CT/11 a.m. PT

1.5 AIA-certified learning units available

 

You must get 12 of 15 questions correct to pass the exam. You may retake the exam if necessary. You will be notified whether you passed or failed automatically after taking the exam. Upon passing the exam, you will receive directions for downloading a PDF of the completion certificate.


Selective coordination for circuit protection is a relatively basic electrical engineering procedure; however, advancements in technologies and constant changes to codes and standards require engineers to regularly update their knowledge and documentation. And besides, even basics need to be drilled or they get fuzzy, which can lead to design and selection errors. Furthermore, new market trends require learning new skills, and the emergence of solar electric (photovoltaic) systems has brought PV circuit protection to the forefront.


This three-part webcast begins with a brush-up on circuit protection basics for fuses and circuit breakers. Part 1 is brush-up on the fundamentals of circuit protection and selective coordination calculations for fuses and circuit breakers. Part 2 applies these basics to a data center project. Part 3 instructs on circuit protection for PV systems and how arc fault protectors, which are required in the 2011 National Electric Code, can increase the fire safety of roof-mounted PV systems.


Speakers:

  • James Ferris, Electrical Project Engineer, TLC Engineering for Architecture
  • Keith Lane, PE, RCDD/NTS/RTPM, LC, LEED AP, President and CEO, Lane Coburn and Assoc. LLC
  • David Dini, PE, Research Engineer, Underwriters Laboratories

1.) Full Name *
2.) Street Address 1 *
3.) City *
4.) State *
5.) Zip Code *
6.) Email Address *
7.) Telephone Number *
8.) Company/Organization Name *
9.) AIA member number
10.) Based on the presentation given by Jim Ferris, PE: *

Selective coordination is defined by:

NEC Article 100
NEC Article 110
NEC Article 415.a.1
11.) Based on the presentation given by Jim Ferris, PE: *

Selective coordination is meant to protect which types of electrical system components:

Transformers
Cables
Motors
Generators
All of the Above
12.) Based on the presentation given by Jim Ferris, PE: *

One way to verify there is selective coordination between breakers is to plot the breaker trip curves in a time current curve format. The time current curve must demonstrate that the breaker curves do not overlap each other.

True
False
13.) Based on the presentation given by Jim Ferris, PE: *

Time-current curves are used to show how fast a breaker or fuse will trip and at what level of current.

True
False
14.) Based on the presentation given by Jim Ferris, PE: *

Selective coordination tips include:

Start coordination at the generator
30A breakers in lighting and receptacle panelboards are difficult to coordinate
Electronic trip breakers are easier to coordinate, but cost 10x more
All of the above
15.) Based on the presentation given by Jim Ferris, PE: *

Coordination does not require familiarity with types of fuses and breaker types or attention to the effect coordination has on the available arc-flash energy.

True
False
16.) Based on the presentation given by Keith Lane, PE: *

It’s not worth spending extra dollars for higher-quality electronic distribution protection equipment unless a proper coordination study is performed by an experienced engineer.

True
False
17.) Based on the presentation given by Keith Lane, PE: *

Data centers are of particular concern for arc flash studies because Mission Critical Facilities can have extremely high levels of fault energy.

True
False
18.) Based on the presentation given by Keith Lane, PE: *

What helps reduce arc flash hazards in data centers is that the optimum settings for selective coordination can result in extremely high levels of arc flash?

True
False
19.) Based on the presentation given by Keith Lane, PE: *

Advanced motor relays on medium voltage transformers allow the operator to reduce selective coordination during maintenance operations and reduce arc flash levels and safety.

True
False
20.) Based on the presentation given by David Dini: *

Arc faults in PV systems are not caused by:

Degradation of insulating materials
Deterioration of electrical connections
Static electricity buildup from wind blowing across the PV panels
All of the Above
21.) Based on the presentation given by David Dini: *

A listed PV arc-fault circuit interrupter or other system components listed to provide equivalent protection is required by the NEC for PV systems at what size?

Maximum voltage of 40 volts or larger
Maximum voltage of 80 volts or larger
Maximum voltage of 120 volts or larger
Maximum voltage of 240 volts or larger
22.) Based on the presentation given by David Dini: *

For NEC applicability, the PV system  must penetrate the building.

True
False
23.) Based on the presentation given by David Dini: *

An arc-fault interrupter is intended to recognize but NOT mitigate the effects of arcing faults.

True
False
24.) Based on the presentation given by David Dini: *

False tripping could be caused because:

The input current characteristics may look like an arcing waveform
Inrush current peaks may occur during the initial system turn-on when the inverter capacitors charge
Contact arcing during DC disconnect switch operation
All of the Above
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