Electrical Systems

Question 1

metrorail has ___ distinct type of electrical systems

Answer 1

3

Question 2

in the metrorail system, the most important electrical system to the fire service is the traction power system, which is used to ___________

Answer 2

propel the rail cars

Question 3

the second electrical system that is important to the fire service provides electrical power to run lighting, ventilation and any other type of service that does not propel the car. this system is a ______power system

Answer 3

AC

Question 4

the emergency power on the metrorail service is provided by _________ power

Answer 4

battery

Question 5

battery power can be found when emergency lighting is needed along with the ________ system

Answer 5

communication

Question 6

a conductor is used to supply power to propel rail cars. the conductor is also known as the __________

Answer 6

third rail

Question 7

The third rail which is converted from AC power to DC power producing _____ volts

Answer 7

750 volts

Question 8

the redundancy of each traction power substation is provided by _____ separate feeders

Answer 8

2

Question 9

pepco supplies _______ volts of power to metro traction power substations

Answer 9

13,800

Question 10

normally, traction power substations can be found every ________ throughout the metrorail system

Answer 10

mile

Question 11

the transformers contain a coolant that does not contain any __________

Answer 11

PCB’s

Question 12

the transformers are located in concrete or block structures with a minimum fire rating of ____ hours

Answer 12

2

Question 13

each transformer is monitored by a sophisticated system that can be shut down the transformer within _______ when a problem arises

Answer 13

30 milliseconds

Question 14

the third rail is _____ inches higher than the running rails

Answer 14

4 1/2”

Question 15

once you pick up the telephone in the ETS box, you dial _____ to talk to OCC

Answer 15

0

Question 16

one should not confuse the volt probe prong color that touches the third rail and WSAD paddle that touches the third rail. both are colored ________

Answer 16

red

Question 17

the pot heads are what color

Answer 17

orange and yellow

Question 18

the grey protective cover located over the third rail is rated at _______ lbs per inch of force

Answer 18

250

Question 19

the max length of third rail section is

Answer 19

800 ft

Question 20

power removal of the third rail can be done two ways ________ and ________

Answer 20

ETS and OCC

Question 21

when testing the third rail with the volt probe, what do you do first?

Answer 21

red probe to running rail

Question 22

an ETS box (blue light station) has an emergency push button that is colored _______

Answer 22

red

Question 23

testing the volt probe can be done by using the 110 volt receptacle located under every other ________ in the tunnels, under every other ______ on the station platform, the walls and occasionally in the floor of ______ platforms

Answer 23

fluorescent lights, bench, station

Question 24

what is recommended if the volt probe shows that the third rail power is down?

Answer 24

retest on a known electrical source

Question 25

if a paddle on the WSAD falls off the ______ will activate

Answer 25

warning horn

Question 26

if the WSAD activated during use or restoration of third rail power, it shall be returned to Metro via ________

Answer 26

the metro liaison officer

Question 27

when OCC receives a call from the ETS box to shut electrical power down, OCC complies buy shutting power down utilizing computer control. this is known as ________

Answer 27

supervisory power outage

Question 28

ETS boxes are located every _____, and at ________of each metro station

Answer 28

800 ft, each end

Question 29

the ETS (emergency trip switch) should only be used when it's ____________

Answer 29

immediate threat to life safety

Question 30

in stations emergency battery power will supply lighting and communications for up to ______ hours

Answer 30

3

Question 31

when emergency power is being used every _____ light above the safety walk will be powered

Answer 31

4th

Question 32

when emergency power is being used _____% of the lighting above the safety walk will be powered

Answer 32

25

Question 33

“stray current” moving between the rail car can be as high as ______ volts

Answer 33

60

Question 34

In regards to “stray current, rail cars and the rails may contain as much as ______ volts after power is shut diwn from the third rail.

Answer 34

60