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5-Minute Tech Quiz

All About PoE

By Roy Pollack
5 min quiz 2019
May 6, 2019

All About PoE (Not the Writer)

All Answers relate to NFPA 70, 2017 Edition

1. PoE was first developed with the establishment of the IEEE standard in __________.
A. 1996
B. 1999
C. 2003
D. 2007
 
2. The standard recommends that the signal crossover be done internally in each hub port. When the crossover function occurs inside a hub port, the standard states that the port should be marked with a _________.
A. C
B. X
C. Y
D. T
 
3. The original PoE standard was designed around Category 3 and 5 specifications, to deliver approximately _________ watts through a powered device with _________ mA of current.
A. 13/350
B. 24/240
C. 15/150
D. 17/270
 
4. The IEEE standard for PoE allowed delivering power on two combinations of two pairs as two different alternatives.  Those alternatives were referred to as _____________
A. PoE 1 and PoE 2
B. Single mode and multi mode
C. Mode A and Mode B
D. 568A and 568B
 
5. How many classes of Power Sourcing Equipment (PSE) have been established?
A. 3
B. 5
C. 9
D. 11
Feedback:  
6. The range of power levels for all PSE classes ranges from ________ to __________..
A. 9 volts/15 volts
B. 30 watts/90 watts
C. 12 volts/18 watts
D. 4 watts/90 watts
 
7. Because of a power loss in cabling, the maximum distance specified is ___________.
A. 100 feet
B. 1,000 feet
C. 100 meters
D. 1,000 meters
 
8. It is apparent that a(n) _____________ in power delivery _____________ current flow, which then results in a(n) ______________ in heat generation within the cabling structure.
A. increase/increases/increase
B. decrease/increases/increase
C. rise/lowers/rise
D. increase/increases/decrease
 
9. An increase in the twist rate of cable pairs creates a longer electrical path.
A. True
B. False
 
10. Which of the following is not a cause of cable temperature increases with PoE deployment?
A. Gauge size
B. Twist rate per inch
C. Improper termination
D. Number of PoE drops 
E. Current
 
SUBMIT
Thank you!
Your score is

 

Answers on page 88.

What’s Wrong With This?

In this photo of new construction, the builder was attempting to get a final so the buyers could move in. The wires are hanging outside the residence. The electrical inspector failed the installation during the inspection. Can you determine the reason for the failed inspection? In addition, can you tell what is correct in this photo? The installer did something that was going to make his life easier.

Ceiling Clip

Click here to see the answer.

Ceiling Clip

Answer to Can You Identify This?:

These wires are for the new homeowner to connect to a future satellite dish that they planned to install. The electrical inspector didn’t like the idea of the wires hanging without being terminated or any indication of what they were for. According to the NEC, any wires that are not terminated must be labeled as not abandoned cable for future use. The contractor went back and installed a tag.

The contractor installed a 1¼ inch PVC pipe protruding on the underside of the soffit into the attic and to the recessed structured cable panel. Why? This will enable him to pull additional wires to this location if necessary.

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KEYWORDS: IEEE standard PoE Power over ethernet security systems

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Roy Pollack, CPP, SET, holds Level IV certification in the field of fire alarms from NICET is currently the director of Compliance for Devcon Security Services Corp., Hollywood, Fla., and may be reached at sdmtechtips@bnpmedia.com.

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