Flashcards in Ch. 10 - Power Distribution.csv Deck (70):

2

## Measure amplitude

###
RMS

(10-2)

3

## Frequency of electric power =

###
50 or 60 Hz

(10-3)

4

## Two wave forms that match each other in electrical degrees are ________

###
In Phase

(not out of phase, in sync, etc..)

(10-4)

5

## Electrical systems between serving utility & customer site is:

###
Distribution system

(10-7)

6

## V = IR

###
Ohm's Law

(test)

(10-9)

7

## V= I= R=

###
V= Voltage

I = Amperes

R = Resistance

(10-9)

8

## Formula for Ohm's Law always applies to _____.

###
DC

(test)

(10-10)

9

## Z =

###
Impedance

(test answer)

(10-10)

10

## Inductive reactive X =

###
magnetic field

(10-10)

11

## Capacitive reactance X =

###
electrical field

(10-10)

12

## Voltage & Current in phase =

###
resistive load

(figure 10.9)

(10-11)

13

## Current lags voltage =

###
Inductive circuit

(figure 10.10)

(10-11)

14

## Current leads voltage =

###
Capacitive load

(figure 10.11)

(10-12)

15

## Apparant power =

###
Measured voltage

(10-12)

16

## Real power =

###
Calculation

(10-12)

17

## Utility companies charge for power in ________.

###
Killowatt hours (kwh)

(10-13)

18

## One kwh is equal to _________

###
1000 watt-hours

(10-13)

19

##
Test question: 1850 watt hours x 24 hours a day x 30 days = 1332.00

1332 x 0.075 = ________

###
$99 month

(10-13)

20

## 1 watt = ________ btu/hr

###
3.413 btu/hr

(10-14)

21

## watts x 3.413 =

###
heat dissipation in BTU

(test)

(10-14)

22

## Formula for tons of A/C:

###
# of watts x 3.413/12000= (answer) tons of A/C

(test)

(10-14)

23

## BTU/12000 =

###
tons of air conditioning

(10-14)

24

## AWG accepted =

###
Worldwide

(10-16)

25

## Sizes in the AWG system represent

###
# of steps

(test)

(10-16)

26

## AWG smaller #'s =

###
larger wires

(10-16)

27

## AWG larger #'s =

###
smaller wires

(10-16)

28

##
AWG smallest size = ______

largest size = ______

###
-36 awg

-4/0 = 460 mil

(10-16)

29

## Circular mills =

###
4/0 & above

(10-17)

30

## Swell =

###
increase, 05. cycle - 1 minute

(10-20)

31

## Sag =

###
decrease, 0.5 cycle - 1 minute

(10-20)

32

## Undervoltage =

###
decrease, 3600 cycles (1 minute)

(10-20)

33

## Harmonics caused =

###
Solid state equipment

(10-21)

34

## Harmonic distortion =

###
size the neutral conductor to carry 200% of the load

(10-23)

35

## K rating tells of the transformer ability to _______

###
dissipate heat

(10-24)

36

## The higher K rating

###
the better the transformer

(10-24)

37

## K-20 =

###
best for data centers

(10-24)

38

## N Tier classification =

###
need

(test)

(10-31)

39

## N-1 =

###
1 additional heat unit

(10-31)

40

## N-2 =

###
2 additional heat units

(10-31)

41

## 2N =

###
2 complete units

(10-31)

42

## 2 (N+1) =

###
2 complete (N+1) units

(10-31)

43

## Voltage regulator =

###
adjusts voltage

(10-39)

44

## Harmonic filters =

###
reduce voltage

(10-39)

45

## Motor generator =

###
utility to drive a motor

(no fuel)

(10-39)

46

## Engine powered generator =

###
fuel-powered

(10-40)

47

## Rectifier/Charger =

###
AC to DC

Charges the battery

(test)

(10-55)

48

## Inverters =

###
DC to AC

(test)

(10-55)

49

## Low voltage disconnect (LVD)

###
used to disconnect the battery

(10-56)

50

## Batteries do not store electricity, they store ________

###
energy

(10-66)

51

## Three main types of battery cells

###
-alkaline

-flooded

-VRLA

(not zinc oxide)

(10-66)

52

## Cells can be connected in _______ to increase battey capacity.

###
parallel

(test)

(10-66)

53

## Most common alkaline cell =

###
NiCd cell

(10-67)

54

## Battey cell of choice =

###
lead-calcium

(10-67)

55

## Battery room ventiliation

###
min. of four changes per hour

(10-67)

56

## What info. is needed for battery cell sizing?

###
-Direct current required

-Direct current input window

-Operating temp of batt.

-Batt. backup time

(not: fit)

(10-70)

57

## How many batteries in parallel recommended?

###
5

(test)

(10-73)

58

## Battery temperature =

###
77ºF

(test)

(10-73)

59

## Battery life decreased 50% for each _____ above optimum operating temp.

###
50ºF

(10-73)

60

## Avoid exposing batteries =

###
-direct sunlight

-adjacent to heating/cooling

(10-75)

61

## Floodcell battery =

###
Eye wash facility

(10-75)

62

## The harmonics of the sine wave are _____of the_____frequency.

###
Multiples, basic

(10-21)

63

## A(n) ____ UPS topology is usually reserved for extremely large critical facilities.

###
ring bus

(10-52)

64

## Shielded isolation transformers provide added level of protection for sensitive & critical equipment & are preferred over standard isolation transformers where the total load is made up of more than ____% of nonlinear type equipment.

###
20%

(10-37)

65

## In power distribution, feeder and branch circuit conductors should be sized for:

###
the non-continuous load +125% of the continuous load.

(10-23)

66

## An isolation transformer is a transformer that:

###
has no electrical connection between the primary and secondary.

(10-37)

67

## A current that periodically reverses its direction of flow is referred to as:

###
Alternating current

(10-2)

68

## In most ac circuits, there is a reactive component that causes the current to ______ the voltage waveform.

###
lead or lag

(10-11)

69

## The difference between real power (in watts) and apparent power (in volt-amperes) required by the load in an ac circuit is caused by:

###
Inductance and Capacitance

(10-9)

70

## What is the equation used to calculate horsepower (HP) for two-phase power?

###
HP = V x I x efficiency x power factor x 2 / 746

(10-14)

71