CPCT Grounding, Bonding & Electrical Protection 3

Question 1

What is the minimum cross-sectional area specified by TIA-607 for the TMGB?

Accepted Answer

6 mm × 100 mm

Answer

TIA-607 specifies the TMGB must be at minimum 6 mm thick by 100 mm wide (with length as required) to provide adequate surface area for bonding connections.

Question 2

During a grounding system inspection, a technician finds a high-resistance connection between the TGB and the TMGB. What is the most likely cause?

Accepted Answer

Oxidation or a loose mechanical connection on the conductor terminations

Answer

High resistance in grounding connections is most commonly caused by oxidized surfaces or loose lugs at termination points, not conductor sizing or installation order.

Question 3

A lightning protection system on a building must be bonded to the telecommunications grounding system because:

Accepted Answer

NEC and TIA standards require all metallic systems to share the same grounding reference to prevent potential differences during a lightning strike

Answer

Bonding all grounding systems together prevents dangerous potential differences between metallic systems during a lightning event, which could cause arcing or equipment damage.

Question 4

Which tool is used to measure the resistance of a grounding electrode to earth?

Accepted Answer

Earth ground resistance tester (fall-of-potential method)

Answer

Earth ground resistance testers using the fall-of-potential method inject current between auxiliary electrodes to accurately measure the resistance of a grounding electrode to earth.

Question 5

What is the correct installation practice when the TBB must pass through fire-rated walls or floors?

Accepted Answer

The penetration must be sealed with an approved firestop system rated for the wall or floor assembly

Answer

All penetrations through fire-rated assemblies, including grounding conductors, must be sealed with UL-listed firestop materials rated to match the assembly's fire rating.

(CPCT) Certified Premises Cabling Technician Practice Test

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CPCT Grounding, Bonding & Electrical Protection 3