block 11 2a

Question 1

in line interactive UPS, the inverter provides what two functions?

Answer 1

• rectifier provides power to batteries to maintain their charge (power)
• Filters main power going to the communications equipment (filtering)

Question 2

The three main parts of emergency power systems are

Answer 2

• batteries
• rectifier
• inverter

Question 3

batteries

Answer 3

• provides dc energy + needs dc to recharge batteries
• one or more cells for chemical reaction that creates electricity
• lead acid batteries most common

Question 4

rectifier

Answer 4

• converts Alternating Current (AC) to DC
• needed to supply DC power to recharge batteries
• also used as power filters to protect sensitive equipment from power spikes, power sags, and other issues

Question 5

inverter

Answer 5

• an electrical component that converts DC to AC
• used when power source,( ie: battery), provides DC power
• most power distribution system + com equipment are designed to use AC

Question 6

Uninterruptible power supply (UPS)

Answer 6

an electrical power device with a battery (or batteries), rectifier, and inverter

Question 7

The three main purposes of an UPS are to:

Answer 7

• Provide short-term temporary power to a computing device in the event of main power failure
• Initiate the graceful shutdown of servers and PCs (Optional)
• Provide protection from power surges/spikes

Question 8

If an abnormality is detected, such as a surge or sag in voltage or current, the UPS __________, or “cleans”, the power so that communications equipment can continue to function.

Answer 8

filters

Question 9

In the event of complete main power failure, the UPS can temporarily provide

Answer 9

power from its batteries until main power is restored or generators can come online.

Question 10

In the event main power is not restored before the UPS’s batteries are depleted and a generator is not available, some UPSs can direct servers and other communications equipment to

Answer 10

start their graceful shutdown process so that equipment damage and data corruption are prevented.

Question 11

three common types of UPSs

Answer 11

standby, line interactive, and double conversion (sometimes called online)

Question 12

standby UPS

Answer 12

• passes main power through to the communications equipment
• only switches to its batteries and inverter in the event of main power variations or failure
• most used for PCs

Question 13

line interactive UPS

Answer 13

• main power is still the primary power source
• inverter is always on
• involved with power delivery to the communications equipment

Question 14

line interactive UPS is most commonly used for

Answer 14

servers

Question 15

double conversion UPS

Answer 15

• rectifier is connected to the main power feed, and the AC is converted to DC
• inverter converts DC back to AC for delivery to power outlets.
• converts the power twice during normal operation
• very clean and reliable power to comms. equip.

Question 16

double conversion UPS is most commonly used for

Answer 16

multiple racks or entire rooms of communication equipment

Question 17

facility battery backup power

Answer 17

operate similarly to double conversion UPSs but the batteries are ALWAYS in use

Question 18

The main purpose most of the communication facility battery backups is to

Answer 18

provide** medium-term** power to critical communications equipment
(main analog phone switch and support equipment, such as operator terminals).

Question 19

Many factors impact the amount of time the facility battery backup system can provide power, including:

Answer 19

• the ampere hour rating of the batteries
• condition of the batteries
• charge level of the batteries
• amount of power consumed by the communications equipment.

Question 20

For most COs and other communications facilities without standby generators, the batteries ________ ______________ to provide power for approximately eight hours

Answer 20

are required

Question 21

For COs and other communications facilities with a standby generator, the batteries should provide power for

Answer 21

3-5 hours

Question 22

generators designed to provide

Answer 22

medium- to long-term power to a communications facility in the event of an extended main power outage

Question 23

generator converts

Answer 23

mechanical energy to electrical energy

Question 24

The reason the UPSs and facility battery backups are included in the power consumption calculation is because

Answer 24

the generator needs to provide sufficient power to recharge the batteries of these systems, along with running the other equipment and systems of the facility

Question 25

genset

Answer 25

generators connected together to act as one unit

Question 26

What is the purpose of an UPS?

Answer 26

• Provide short-term temporary power to a computing device in the event of main power failure
• Initiate the graceful shutdown of servers and PCs (Optional)
• Provide protection from power surges/spikes

Question 27

What are some limitations of using an UPS?

Answer 27

small amount of power supply/short-term temporary power. wouldn’t keep larger pieces of equipment running for that long

Question 28

What components allow the conversion of AC to DC and DC to AC?

Answer 28

Double Conversion UPS

Question 29

Why might a facility have battery backup power instead of an UPS?

Answer 29

• is much larger and provides medium-term (more energy).
• also battery backup facilities ALWAYS RUN whereas USPs only work when power goes out, etc.

Question 30

How do generators generate AC power?

Answer 30

a generator has an engine and an alternator along with many monitoring and control systems. The engine is usually powered by diesel fuel. Attached to the engine is a drive shaft that connects to an alternator. As the engine runs, it spins the drive shaft, which spins the alternator. The alternator produces AC power that is provided to the facility’s power distribution system.