Power Systems & Grounding Flashcards
7 cards from real CTE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Power Systems & Grounding flashcards as text
What is the primary function of a Surge Protective Device (SPD) in a telecommunications system?
Answer: To divert transient overvoltages safely to ground, protecting equipment from damage
An SPD clamps and diverts transient overvoltages — caused by lightning strikes or switching events — to the grounding system, preventing them from reaching and damaging sensitive telecommunications equipment.
In a standard -48V DC telecommunications power system, which terminal is connected to ground?
Answer: The positive (+) return terminal is grounded, and the negative (-48V) terminal supplies power to equipment
In the standard -48V DC telecom convention, the positive (return) bus is grounded at the battery plant, and the negative (-48V) bus carries the supply voltage to equipment.
In telecommunications infrastructure, what does the term 'bonding' specifically refer to?
Answer: The permanent electrical joining of metallic parts to form a low-impedance conductive path
Bonding refers to the permanent joining of metallic components to ensure electrical continuity and the capacity to safely conduct fault current, as defined in both NEC and TIA-607.
What fuel type is most commonly used for backup generator sets in large telecommunications central offices?
Answer: Natural gas or diesel fuel
Natural gas and diesel are the dominant generator fuels in large telecom facilities; diesel provides on-site stored fuel for extended outages while natural gas leverages utility pipeline supply.
What is the primary function of a Battery Management System (BMS) in a modern telecommunications power plant?
Answer: To continuously monitor battery state of charge, temperature, voltage, and overall health to optimize performance and lifespan
A BMS monitors critical battery parameters including state of charge, cell voltage, temperature, and internal resistance to detect degradation, prevent over-discharge, and extend battery service life.
Per GR-63-CORE NEBS Level 3, across which seismic zones must telecommunications equipment be qualified to operate safely?
Answer: All seismic zones 0 through 4 (equipment must meet the most stringent zone requirements)
NEBS Level 3 certification requires equipment to be seismically qualified for all zones 0 through 4, ensuring it can be deployed anywhere in North America regardless of local seismic risk.
What is the fundamental difference between a UPS system and a DC power plant as used in telecommunications?
Answer: A UPS provides conditioned AC output to AC-powered equipment, while a DC power plant provides -48V DC directly to DC-native telecommunications equipment
A UPS converts power to AC output for AC-powered equipment, while a telecom DC power plant (rectifier + battery string) directly supplies -48V DC to equipment designed for that native DC input.