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8th Six Months > 8th Six Months > Flashcards

8th Six Months Flashcards

1
Q

You can control chain tension by changing shaft centers or using a?

A

Idler sprocket

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2
Q

A roller chain should be allowed to sag ___ percent of the distance between sprocket centers.

A

About 2

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3
Q
  1. In chain operations, the areas of greatest load are the?
A

Chain joints

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4
Q

You should make your first full-scale inspection of a new drive chain after ____ hours of operation?

A

24

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5
Q

Chain side plates that show signs of uneven wear usually indicate that the?

A

Drive is misaligned

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6
Q

In a vertical chain drive without an idler the shafts should be installed at an angle of no more than?

A

60°

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7
Q

The most common cause of drive chain failure is?

A

Improper lubrication

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8
Q

Which of the following describes the type III lubrication method?

A

Splash

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9
Q
  1. A scraping or slapping noise during a test run of a chain drive may indicate that?
A

The chain is striking something

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10
Q

Before using chain that has been stored on open reels you should?

A

Clean it with solvent

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11
Q

After mounting sheaves and pulleys, you should check their alignment with a?

A

Straight edge

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12
Q

The best way to tighten a V-belt that has stretched is to?

A

Adjustable center distance between sheaves

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13
Q

A splice commonly used on low-speed flat belts is the ___ splice?

A

Stepped

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14
Q

. If a new flat belt is running well, how long should you test run it under normal load?

A

48 hours

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15
Q
  1. A burned spot on a belt probably indicates?
A

Belt is overloaded

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16
Q

Which type of belt is installed on sheaves rather than on pulleys?

A

V belt

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17
Q

If a v-belt in a multi belt drive shows wear you should?

A

Replace the full set of belts

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18
Q

Which of the following is the correct way to check a V-belts tension?

A

Apply a specific amount of force to the top side of the belt

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19
Q

Which of the following is the best way to take up slack in a flat belt?

A

Adjust the center distance

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20
Q

The pulleys for a positive drive belt have a?

A

Flange on each side

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21
Q

Which of the following drives permits practically no misalignment of the shafts?

A

Gear

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22
Q

The critical dimension that ensures accurate meshing of a worm and worm gear is its?

A

Distance between the centers

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23
Q

When mounting spur or helical gears that have only one hub, you should position the hub?

A

Away from the bearing

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24
Q

When cracked or broken areas appear on teeth that are almost new, the cause is probably a?

A

Foreign object

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25
Q

If the metal at the tips and roots of gear teeth has been gouged or worn, the cause is probably?

A

Too tight a fit between gears

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26
Q

Which of the following happens to open gearing during the run in period?

A

Gear polish up

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27
Q

The DP of a gear is the ratio of the number of teeth to the ____ in inches.

A

Pitch diameter

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28
Q

Which of the following is used to check gear alignment after installation?

A

Steel square

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29
Q

What should you do if spalling occurs in an open gear drive?

A

Gear treat the teeth

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30
Q

Which of the following is the best solution for gearing with cracked rims?

A

Replace the gear

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31
Q

When installing an enclosed gear drive on the floor you should mount the feet on the?

A

Steel base pads

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32
Q

What components of an enclosed gear drive prevents the buildup of pressure or the formation of a vacuum inside the drive housing?

A

Breather

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33
Q

If an enclosed gear drive is to be stored in the plant for a long time, you should?

A

Fill the drive completely with oil

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34
Q

Most unusual noises that develop after an enclosed gear drive has run a while originate in the?

A

Shaft bearings

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35
Q

What does discoloration of worm gear teeth indicate?

A

Burning by overloading

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36
Q

Which tool is used to check the levelness of an enclosed gear drive on its foundation?

A

Spirit level

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37
Q

Which is the most common method of lubrication for bearings on enclosed gear drives?

A

Splash

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38
Q

During the run in period you should run the drive system at half load for __ to ___hours.

A

8-10

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39
Q

After a gear drives first week of operation under full load you should?

A

Check the oil level

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40
Q

Which of the following is found on the nameplate of an enclosed gear drive?

A

Load capacity

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41
Q

Which elements of the drive package should you move to set the coupling gap?

A

Motor

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42
Q

What instrument is used when very precise coupling alignments must be made?

A

Dial indicator

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43
Q

What instrument is used when very precise coupling alignments must be made?

A

Dial indicator

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44
Q

A floating shaft coupling should be used when the?

A

Drives exert axial thrust

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45
Q

If the power requirements of a driven machine have been changed so that over-loading occurs you can solve the problem by installing the?

A

Next larger coupling

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46
Q

A coupling can serve all of the following purposes except?

A

Insulate against high temperatures

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47
Q

The gap between spacer couplings and the hubs should be ___ inches?

A

0

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48
Q

What is the usual cause of whipping on a floating shaft?

A

Excessive misalignment

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49
Q

An uneven wear pattern on a gear type coupling is usually a sign of?

A

Misalignment

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50
Q

The slack in the fit between coupling components is known as?

A

Backlash

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51
Q

The most common cause of failure in jaw clutches is?

A

Jaw breakage

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52
Q

V-belt sheaves, shafts and gears can all be used as?

A

Takeoff members

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53
Q

Localized wear on clutch friction surfaces often indicates?

A

Misalignment

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54
Q

Frequent slippage of a brake or clutch is usually an indication of?

A

Overloading

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55
Q

Chatter is usually caused by?

A

Loose or faulty actuating devices

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56
Q

Friction clutches use one or more discs to?

A

Transmit torque to the load

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57
Q

Rapid wear between the friction surfaces by an electric brake or clutch is usually the result of?

A

Overheating

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58
Q

When the slip speed of a clutch drops to zero, the maximum torque of the clutch can exert?

A

Increases

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59
Q

The capacity of a clutch to dissipate heat depends on its size and?

A

Armature speed

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60
Q

If a brake or clutch fails to engage properly, the first thing to check is the?

A

Voltage supply to the coil

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61
Q

At _____ output speed, the flanges on the input shaft of an adjustable-speed drive are?

A

Maximum; closest together

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62
Q

The best protection against unwanted heat in a an enclosed drive is a?

A

Steel baffle

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63
Q

When test running and adjustable speed drive under no-load conditions, it is necessary to operated the drive?

A

Through its full speed range

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64
Q

If you find ridges in a drives sheave flanges on an adjustable speed drive you should?

A

Sand or polish the ridges away

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65
Q

In an enclosed drive, high temperatures usually result from a?

A

Overloading the shaft bearing

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66
Q

The amount of slip between a turbine and its impeller is normally a difference of ____ to ____ percent at full load.

A

3 to 5

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67
Q

A condition called a “stall load” can occur in a fluid coupling when the impeller _____ and the turbine ______?

A

Rotates; does not rotate

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68
Q

Over heating in a fluid coupling is usually caused by ?

A

Too much slip

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69
Q

A polyphase torque converter has _____ stators that _____?

A

Two or more; rotate

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70
Q

If you find seals that are hard and cracked when you are inspecting a coupling, you should ?

A

Replace them

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71
Q

An enclosed gear drive thermal capacity is usually expressed in?

A

Horsepower

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72
Q

When you need to change the speed of a load shaft you should select a drive with a?

A

Adjustable speed belt

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73
Q

The major cause of drive failure is?

A

Improper lubrication

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74
Q

If an overload occurs in a drive system that is equipped with a spring-operated overload device the?

A

Sprocket will slip

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75
Q

When test running a drive prior to placing it in service, you should run the drive under no-load conditions for?

A

20-30 minutes

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76
Q

Which of the following diagrams represents the proper sequence for tightening hold-down bolts when installing an enclosed adjustable speed drive?

A

C
1 3
2 4

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77
Q

The best way to determine the correct running clearance in a plain-bearing is to?

A

Consult manufacturers charts and tables

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78
Q

The ability of bearing material to dissipate excessive heat generated during operation is called?

A

Thermal conductivity

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79
Q

The ability of bearing material to flow slightly when loaded is called?

A

Conformability

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80
Q

An advantage of grease compared to oil in lubricating a plain bearing is that?

A

Newly applied grease forced old lubricants out

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81
Q

Discoloration in plain bearings is generally a symptom of?

A

Excessive heat

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82
Q

Which of the following should be used to measure the running clearance of a plain bearing?

A

Feeler gauge

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83
Q

Which method should be used to remove moisture from a bearing shell after it has been cleaned?

A

Preheating

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84
Q

When building a plain bearing liner, coat the mandrel with ___ to keep molten Babbitt from clinging.

A

White lead

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85
Q

What is the purpose of the grooves cut onto a plain bearing liner?

A

Circulate lubricant

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86
Q

Which is the most likely cause of screeching from a plain bearing during operation?

A

Clearances are too tight

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87
Q

If you must leave your workplace temporarily, what care should you give a new, unmounted antifriction bearing?

A

Wrap it in oil resistant paper

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88
Q

. To prevent creeping of an inner bearing ring around the shaft, you should mount the inner ring with an ___ fit.

A

Interference

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89
Q

You can force an antifriction bearing into position on the shaft by using an arbor press or by impact, if the bearing has an O.D. of?

A

4 inches or less

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90
Q

A bearing is driven up a split tapered adapter by?

A

Tightening a heavy duty locknut

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91
Q

At approximately what temperature should you begin to suspect a bearing problem?

A

At approximately 185°F

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92
Q

You clean an antifriction bearing before installation if it?

A

It will be lubricated by automatic oil mist

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93
Q

If the shoulder is too low when seating an antifriction bearing on the shaft the?

A

Inner ring may distort

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94
Q

When inspecting a tapered shaft by blueing the gauge bore, a ___ % blueing transfer is acceptable?

A

80%

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95
Q

When cold mounting an antifriction bearing, you must?

A

Lubricate the bearing bore and shaft with light oil

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96
Q

Which of the following is not an approved way to heat a roller bearing for a temperature mount?

A

Gas operated torch

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97
Q

What is the correct tool to use when removing a locknut from an antifriction bearing installation?

A

Spanner wrench

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98
Q

When you use a puller to remove a taper-mounted bearing, what should you do with the locknut?

A

Back the nut off several turns

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99
Q

An aluminum heating ring is designed for mounting and dismounting the inner rings of a ___ bearing.

A

Cylindrical roller

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100
Q

When you use an aluminum heating ring to expand a bearing, heat the ring to?

A

500°F

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101
Q

If you have cleaned and inspected an antifriction bearing but do not intend to reuse it immediately, how should you treat it before wrapping it in oil-resistant paper and storing it?

A

Fill it with grease

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102
Q

The two main methods of removing antifriction bearings are?

A

Impact and heating

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103
Q

Which of the following is a correct way to remove an antifriction bearing with a diameter smaller than 4 inch?

A

Arbor press

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104
Q

The two important dimensions of a bearing puller are spread and?

A

Reach

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105
Q

To remove a bearing, a splitter may be used with a?

A

Mechanical puller

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106
Q

Which of the following should not be used to clean an antifriction bearing when inspecting it?

A

Steam

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107
Q

Which type of bearing seal keeps out water, dirt, and contaminants most effectively?

A

Contact seal

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108
Q

Which type of antifriction bearing can tolerate the most internal misalignment?

A

Spherical roller bearing

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109
Q

The correct tolerance range for shafts from 2 to 4 inches in diameter is nominal to?

A

-.001 inches

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110
Q

When you lubricate bearings with grease, the actual lubricant is ___, which is held in suspension.

A

Mineral oil

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111
Q

As a rule, the interval between lubrication renewals is cut in half for every 27 degrees Fahrenheit increase in temperature above?

A

160°F

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112
Q

. A special type of pillow block sometimes used on belt conveyors is called a?

A

Takeup

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113
Q

When using the grub screw method to hold a bearing in a pillow block, use?

A

No collar

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114
Q

To find the takeout amount needed to calculate final clearance when installing a bearing, refer to the?

A

Manufacturers chart

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115
Q

Which type of lubricant increases the effectiveness of a labyrinth seal?

A

Grease

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116
Q

Bearing temperature is typically ___ to ___ degrees Fahrenheit higher than the temperature of the housing.

A

15° to 25°

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117
Q

The threads of an acme screw are?

A

Squared off & thick

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118
Q

Ball bearing screws are designed to?

A

Move loads vertically and horizontally

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119
Q

The screw in a ball bearing screw is supported by?

A

Standard ball bearings

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120
Q

. In a contact seal, what forms the actual seal?

A

A thin film of oil

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121
Q

Before you install a lip seal, chamfer the end of the shaft and the leading edge of the housing bore at an angle of ___ to ___ degrees.

A

15 to 30

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122
Q

The rolling contact of a ball bearing screw is ___ % efficient.

A

90%

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123
Q

Which of the following carries the load moved by a ball bearing screw?

A

Ways

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124
Q

When preparing a ball bearing screw for installation, use a ___ to expand the inner ring of the bearings.

A

Hot oil bath

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125
Q

Which seal is most effective when large quantities of contaminants are present close to the machinery?

A

V-ring

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126
Q

Which seal material works well for machines operating at extremely low temperatures?

A

Silicone

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127
Q

1 The two units of measuring liquid pressure are?

A

P.S.I ; Foot of head

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128
Q

The available NPSH of a system should be _____ the required NPSH of the pump.

A

Equal to or greater than

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129
Q

The formation of vapor pocket or bubbles within a liquid id called?

A

Cavitation

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130
Q

The horsepower required to actually drive a fluid-handling pump is called the?

A

Brake hp

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131
Q

One electrical horsepower equal ____ watts.

A

746

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132
Q

The area that surrounds and houses the packing in a pump is called the?

A

Stuffing box

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133
Q

When installing four or more packing rings, you should stagger the joints ____ degrees apart?

A

90

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134
Q

The most common mechanical seal configuration is the ____seal?

A

Single internal

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135
Q

9 In some mechanical seals, the rotating element is secured to the shaft by a?

A

Boot

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136
Q

The major cause of burned seals is?

A

Improper lubrication

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137
Q

After grouting a baseplate, you should allow the grouting mixture to set for at least?

A

48 hours

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138
Q

When removing springs from pump feet, you should measure movement with a?

A

Dial indicator

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139
Q

Unwanted movement of a pump shaft along its axis is called?

A

End play

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140
Q

Cavitation is caused by

A

Pressure loss

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141
Q

Loss of clearance between wearing rings is called?

A

Ring seizure

142
Q

On a pump that has both bearings on the same side of the impeller, the bearing nearest the impeller is called the ______ bearing?

A

Inboard

143
Q

The most common sign of cavitation in a pump impeller is?

A

Putting on the back side of the vanes

144
Q

In general, runout on a pump shaft should not exceed ____ inches.

A

.003

145
Q

Too much clearance between the stationary rings and the impeller or rotating rings of a centrifugal pump will cause?

A

Fluid leakage

146
Q

When installing a new gasket, you may wish to apply ____ to the lower half of the casing.

A

Shellac

147
Q

The most commonly used type of all rotary pumps is the ______ pump.

A

External gear

148
Q

In a vane-type rotary pump, what keeps the sliding vanes in contact with the pump housing?

A

Centrifugal force

149
Q

The riser used to vent a system at the discharge side of the pump should be about _______ times as long as the diameter of the pipe?

A

5

150
Q

Internal bearings on rotary pumps are most often lubricated by?

A

The fluid being pumped

151
Q

If a rotary pump is not delivering fluid at its discharge side, the first thing you should do is?

A

Stop the pump

152
Q
  1. Which method is used to measure a pipe with a fitting at one end?
A

End to center

153
Q

Which of the following displayed symbols describes a flanged tee?

A


=
—||—-|—–||–

154
Q

Which type of flange is used to seal the end of a pipe?

A

Blind

155
Q

Given a 45 degree offset shown with a 41 inch travel a center to face elbow dimension of 2 inch and a ¾ inch length, what is the end to end pipe length?

A

38.5 inches

156
Q

Straight internal pipe threads in pipe couplings are represented by the code letters?

A

Npsc

157
Q

. In complete pipe specifications, code letters are preceded by two numbers which indicate the?

A

Nominal pipe size and number of threads per inch

158
Q

The distance from a given point on one pipe thread to the same point on the next thread, measured parallel to the pipe centerline, is called the?

A

Pitch

159
Q

You need to replace a threaded pipe between 45 degree elbows in a straight offset. The set is 5 ft, and the travel is 7.07 ft. The center-to-face dimension of each 45 elbow is 2 in., and the pipes thread length is 3/4 in. The total end-to-end length of the replacement pipe is?

A

82.34 inches

160
Q

Ratchet threaders can be used on pipe up to about ____ inch in diameter.

A

6

161
Q

Socket-welding fittings are used for joining pipe of what diameters?

A

4 inches or less

162
Q

Backing rings should always be made of?

A

Material compatible with the pipe material

163
Q

Squareness is a term indicating that a pipe forms a _____ angle with another.

A

90 degree

164
Q

The major assembly consideration when fabricating flanged connections for a rolling offset is?

A

Aligning the holes

165
Q

The usual gap between pieces of pipe to be butt welded is approximately?

A

3/16 inch

166
Q

A major advantage of thermoplastic pipe is that?

A

It is highly resistant to corrosion

167
Q

Which of the following is a fiberglass-reinforced thermosetting pipe material?

A

RTRP

168
Q

The solvent cement used to install fittings on thermoplastic pipe requires _____ hours to cure completely

A

1/2 to 4 hours

169
Q

When installing threaded fittings on plastic pipe, you should tighten the joint by hand or with a?

A

Strap wrench

170
Q

To ensure a good bond when installing bell fittings on thermosetting pipe, the ends of the pipes should be?

A

Lightly sanded

171
Q

What kind of hanger is used if a rigid hanger would swing more than 4 degrees?

A

Roller

172
Q

A steam trap is a pipefitting accessory that removes?

A

Condensate

173
Q

Steam traps should he installed at the ______ point in the system.

A

Lowest

174
Q

Which of the following fixtures is used to remove very small particles from a piping system?

A

Filter

175
Q

What kind of expansion joints can be used where temperature changes cause axial pipe movements?

A

Slip and bellow joints

176
Q

Water is usually carried in ______ tubing; If it is under high pressure, _____ tubing is usually used.

A

Copper; stainless steel

177
Q

A flareless compression fitting is one that?

A

Bites into tubing

178
Q

Annealing is sometimes necessary to make tubing?

A

Easier to bend

179
Q

When you use a cutter to cut tubing, the cutter should _____ and the tubing should ___?

A

Rotate; not rotate

180
Q

To get the most accurate measurement of required tubing length, you must measure along the path of the tubes?

A

Centerline

181
Q

The tensile strength of tubing is based on the ______ and the ______?

A

Tubing material; wall thickness

182
Q

How does increasing the operating temperature affect the strength of tubing?

A

Decreases it

183
Q

What type of fitting is commonly used on tubing that carries a flammable liquid or gas?

A

Flared

184
Q

What is the first step in installing a flared fitting?

A

Slide the nut over the tube

185
Q

What is the most common cause of leaks in a tubing system?

A

Poor fitting connection

186
Q

What is the most frequently used hydraulic fluid?

A

Oil

187
Q

What device is commonly used to keep hydraulic systems from building up excess pressure?

A

Relief valve

188
Q

What type of fittings should be used with copper tubing in hydraulic systems?

A

Brass

189
Q

If the pump in a hydraulic system is noisy, the most likely cause is a?

A

Insufficient fluid supply

190
Q

Contaminated fluid in a hydraulic system often causes?

A

Fluctuating pressure

191
Q

A typical multipurpose industrial hose can carry saturated steam at pressures of up to?

A

150psi

192
Q

A shaft that serves to support a fitting during assembly is called a?

A

Mandrel

193
Q

The most common method of attaching reusable fittings to hose is?

A

Threading

194
Q

Calculate the required hose length if a 40 degree bend is to be made in a hose and the radius of the bend is 8 in.

A

5.58 inches

195
Q

Hydrostatic tests of a hose system should be conducted at ___ percent of the recommended working pressure of the hose?

A

150

196
Q

The most important dimension of a gasket from a total performance standpoint, is its?

A

Thickness

197
Q

The electrical signal generated by a profilometer is converted into a reading displayed in?

A

RMS

198
Q

Waviness in flange surfaces is usually expressed in _____ of an inch.

A

Thousandths

199
Q

Waviness in flange surfaces is usually expressed in _____ of an inch.

A

Thousandths

200
Q

Coatings serve to reinforce a joint seal and keep the gasket from?

A

Creeping

201
Q

TFE-based gasket strips can accommodate operating temperatures of up to?

A

250°F

202
Q

Which of the following valve materials is the best choice for service conditions that include high pressures, high temperatures, and corrosive fluid?

A

Stainless steel

203
Q

. If a valve must be removed frequently for service or repair, the valve-to-pipe connection should be?

A

Threaded

204
Q

The first step in stopping leakage around the stuffing box of a gate valve is to?

A

Tighten the gland bolt nuts

205
Q

If the stem of a globe valve does not move freely, one likely cause is a?

A

Damage spot on the thread

206
Q

What is usually the first indication of a valve problem?

A

Leakage

207
Q

The first part of a diaphragm valve to wear out it usually?

A

The diaphragm

208
Q

What causes a pop safety valve to open?

A

Pressure rising above a preset value

209
Q

For most pop safety valve, pressure and temperature are usually limited to?

A

250-450psi

210
Q

Chatter in pop safety valves is caused by a _____ volume of flow at a ____ pressure.

A

Low;high

211
Q

What part of a safety relief valve contains the pressure that opens the valve?

A

A huddling chamber

212
Q

A mechanism used to open or close a valve is called a?

A

Actuator

213
Q

The maximum air pressure for pneumatic diaphragm actuators is approximately?

A

125psig

214
Q

Which of the following devices is used to measure fluid pressure?

A

Bourdon tube gauge

215
Q

Which of the following indicates flow rate by producing an electrical signal?

A

Turbine flow meter

216
Q

Accumulators are used for?

A

Storing pressure

217
Q

Applications that call for fully open or fully closed positions are best handled by a ____ valve.

A

Gate

218
Q

The valve best suited for regulating flow is the ______ valve.

A

Angle

219
Q

Which of the following valve materials is most best for use in high-pressure, high temperature conditions?

A

Steel

220
Q

The marking “WOG” on the body of a valve stands for?

A

Cold water, oil, and gas

221
Q

. Flanged joints require the use of ______ to create an effective seal?

A

Gaskets

222
Q

One of the most common signs of insulation failure in steam lines is?

A

Leakage

223
Q

Condensate in a steam tracing system should be drained to the?

A

Collection header

224
Q

One of the disadvantages of electric tracers is that they?

A

Require constant monitoring

225
Q

. The simplest way to protect an exposed water line from freezing is to?

A

Drain the line

226
Q

Which of the following is an example of passive corrosion protection?

A

Installing a pipe liner

227
Q

The machine operator frequently can give the troubleshooter?

A

Valuable information

228
Q

Mechanical, hydraulic, and pneumatic systems all are worked on by the?

A

Mechanical troubleshooter

229
Q

The purpose of good maintenance is to?

A

Keep machines and equipment working

230
Q

A maintenance specialist reports to craft supervisors in all plant departments in a plant organized under?

A

Central organization

231
Q

In a large plant, the building maintenance group is most likely to be made up of?

A

Electricians, Mechanics, Plumbers, Carpenters, and Painters

232
Q

All communications is essentially a cycle of ____ steps.

A

Four

233
Q

When you give a person a chance to express himself, you may?

A

Find him easier to work with

234
Q

Writing down an order?

A

Helps prevent misunderstandings

235
Q

Before you make a repair, you should?

A

Find out what your responsibilities are

236
Q

If you have a problem or complaint about your job, you should?

A

Report it directly to the supervisor

237
Q

If possible, you should schedule repair work for a time when?

A

The machine is not in use

238
Q

Before you can diagnose problems, you must ?

A

Be able to recognize Normal operations

239
Q

An ohmmeter measures?

A

Resistance

240
Q

Air supplies should be checked?

A

When the machine is running

241
Q

Your first duty in an emergency is to?

A

Protect workers from injuries

242
Q

When should the troubleshooter check the machine drawings in the service manual?

A

Before working on the machine

243
Q

Parts lists do NOT

A

Include a great deal of written technical information

244
Q

High values of resistance can be measured with a?

A

Megohmeter

245
Q

A bourdon tube is used to measure?

A

Pressure

246
Q

Which of the following instruments measures the difference between two temperatures?

A

Thermocouple

247
Q

The tools in your toolbox do NOT need to be?

A

New

248
Q

When should you remove your lock from the machine controls?

A

After you have replaced the machine guards and covers

249
Q

To recheck a system after making a repair, you should?

A

Run the system under both automatic and manual controls

250
Q

Drive chains that run at speed of over 500 feet per minute require?

A

Constant lubrication

251
Q

Which of the following conditions indicated conveyor overload?

A

Uneven spaces between the top plates of the conveyor chain

252
Q

The diagram that shows both the external shape and the internal working parts of a system or a component is a?

A

Cutaway diagram

253
Q

A piping system is shown in three dimensions in a?

A

Isometric diagram

254
Q

A wiring diagram shows the?

A

Physical relationships of devices in an electrical system

255
Q

Which of the following is used to trace the wiring in the ceilings and walls of a building?

A

Lighting diagram

256
Q

Step-by-step instructions for testing equipment are included in a?

A

Troubleshooting chart

257
Q

Modern precision-built bearings?

A

Help support power transmission shafts

258
Q

Side-to-side movement of a shaft in a sleeve bearing should be no more than?

A

Two thousandths of an inch

259
Q

NOT all centrifugal compressors have?

A

More than one air supply

260
Q

Centrifugal, wet, and bag are types of?

A

Mechanical dust collectors

261
Q

Synthetic coatings greatly improve the strength and resistance of a?

A

Floor

262
Q

Electrical switchgear consists of?

A

Equipment that controls, protects, and regulates machinery

263
Q

A panelboard is a small assembly that contains?

A

Either fuses or circuit breakers

264
Q

Which type of diagram shows the parts of a circuit as they actually appear to the eye?

A

Pictorial

265
Q

The basic unit for measuring electric current is the?

A

Ampere

266
Q

Potential difference is measured with a?

A

Voltmeter

267
Q

In a normal work-order procedure, which of the following jobs is done by the scheduler?

A

Issues the work order

268
Q

Determining what parts and supplies are needed to make an emergency repair is the job of the?

A

Emergency crew

269
Q

The best approach for identifying the cause of a breakdown in automatic machinery is?

A

The systematic one

270
Q

The decision to run a machine part to the point of breakdown must be made?

A

Very carefully

271
Q

Wear to machine parts caused by contact with chemically active materials is an example of?

A

Corrosion

272
Q

The inspection and repair of plant equipment at regular intervals is called?

A

Planned maintenance

273
Q

The work order form is used for?

A

Issuing instructions and obtaining feedback

274
Q

Which of the following machine parts require daily lubrication?

A

Shafts and bearings

275
Q

All of the following will cause a drive belt to deteriorate EXCEPT?

A

Too much ventilation

276
Q

The sag in a drive chain should be about 1/4 in. for every ______ in. of distance.

A

12

277
Q

The rotating weight of the unit is transferred through the trust bearing, though the upper bridge, and trough the _______ to the foundation.

A

Stator frame

278
Q

On an umbrella unit, the thrust bearing is located?

A

Below the rotor

279
Q

The three types of thrust bearings are?

A

Adjustable shoe, self equalizing and spring loaded

280
Q

The adjustable shoe thrust bearing uses a ______ under each of the shoes for adjusting the height and loading of the shoes.

A

Jack screw

281
Q

To install the thrust block, it is heated to a predetermined temperature and lowered over the shaft, again with the unit on jacks. The block is set on the _____. The rigging removed, and the radial keys and the keeper installed.

A

Thrust shoe

282
Q

With the thrust block still hot and installed on the shaft, the jacks are released to?

A

Allow the full weight of the unit to set the block in place against the keys

283
Q

Using the thrust bearing high pressure lubrication system, allows for both ____ and ____ movement required during the alignment process.

A

Rotational; lateral

284
Q

As alignment deviates, loading on the guide bearings will increase a will ____ levels.

A

Vibration

285
Q

Any increase in vibration from misalignment will decrease the ___ factor of operation in severe circumstances.

A

Safety

286
Q

The concentricity of the stationary components can be checked by?

A

Hanging a single tight wire to check plumb reference

287
Q

The tolerance for plumb center of shaft runout is ____ multiplied by the length of the shaft from the highest plumb reading to the lowest plumb reading in inches.

A

0.000025

288
Q

The tolerance for shaft straightness should not be more than ____ inch from a straight line connecting the top and bottom reading point.

A

.003

289
Q

The parallel misalignment between two shafts that occurs at the coupling between the generator and turbine shaft is called?

A

Offset

290
Q

Shaft dogleg is?

A

Angular misalignment of the turbine and generator shafts

291
Q

Plumb wires should be hung _______ apart.

A

90°

292
Q

The first preliminary check during the alignment process, it to loosen the mounting bolts on each leg of the upper bridge to check for?

A

Soft foot

293
Q

One of the most important things to check before taking alignment readings is to make sure the?

A

Shaft is free

294
Q

The procedure that is particularly useful during major overhauls is to temporarily install the upper and lower bridges and the head cover to check the concentricity of the stationary components with a single plumb wire and a?

A

Electric micrometer

295
Q

When the unit is centered the concentricity can be checked by taking _____ readings at the turbine guide bearings, seal rings, generator air gap, etc.

A

Clearance

296
Q

Correcting dogleg between the generator and turbine shafts requires installing a shim pack between the?

A

Coupling faces

297
Q

The second method used for aligning Hydrounits with adjustable shoe thrust bearings is using the adjustable feature of the shoes only to achieve equal?

A

Loading

298
Q

On self equalizing thrust bearings, one step in the procedure is to center the shaft in the ________ housing and move the ______ of the shaft to make plumb.

A

Turbine bearing; top

299
Q

The final step in the alignment process is the installation and adjustment of the?

A

Guide bearings

300
Q

To make the generator guide bearings concentric to the turbine guide bearing, the _____ is used as a reference.

A

Shaft

301
Q

When installing the turbine bearing, several ____ are used to prevent lateral movement.

A

Dowels

302
Q

Although vertical hydrounit machines may be extremely large?

A

Close tolerances must be maintained

303
Q

The vertical hydrounit machine that has the thrust bearing and upper guide bearing located above the rotor is called?

A

Suspended type

304
Q

On large low-speed vertical hydrounit machines, the rotor poles are secured to the rim by?

A

Driven tapered keys

305
Q

On an adjustable blade pump or propeller (kaplan) type turbine, a hollow shaft is required on the electrical machine to?

A

Allow oil pipes to be carried through the shaft from the oil head at the top of the unit to The turbine servomotor

306
Q

On guide bearings, lubrication arrangements eliminate the need for an oil circulating system. The designated oil level is usually about ____ the length of the bearing above its lower end.

A

1/3

307
Q

Brakes are usually operated by compressed air at ____ psi. When used as jacks, the brakes are operated by an oil pressure of ______psi.

A

75-100; 1000-3500

308
Q

High pressure bearing lubrication is frequently used to reduce?

A

Break away Torque

309
Q

The high pressure bearing lubrication pump assembly uses a _____ to prevent starting the machine (hydrounit) until the pressure is approximately 1000 psi.

A

Pressure switch

310
Q

Prior to erection of the unit, the turbine or pump runner and shaft are centered and supported in a position at a specified distance usually ________inch below the correct operating position.

A

1/4 to 3/4

311
Q

During the alignment process, fins should be provided on the plumb bob to allow it to hang in a pail of heavy oil to dampen any swings and protect the plumb line from?

A

All strong air currents

312
Q

Electric welding on any part of the machine is a serious hazard to bearings. A bearing surface can be damaged?

A

Rapidly if welding current passes through it

313
Q

In regards to hydrounits, if possible all electric welding should be done?

A

Before bearings are assembled

314
Q

The thrust bearing tub cooling coil should be water-tightness tested to a water pressure of _______% of normal working pressure.

A

150

315
Q

Precautions should be taken during assembly of the thrust bearings to avoid?

A

A.T.A.

316
Q

Segmental bearings made up of independently adjustable segments must be set to?

A

Proper elevation and clearance

317
Q

To eliminate the possibility of shaft current, bearings and other parts should be?

A

Insulated

318
Q

Check the insulation with a _____ volt insulation meter, if the resistance is less thank ____ohms inspect the insulation and make necessary corrections

A

500; 20,000

319
Q

Before drawing the couplings together, their mating surfaces must be in alignment, parallel, clean and free from burrs. The coupling must be drawn up?

A

Evenly to prevent distortion

320
Q

Coupling bolt tension can be determined by an accurate measurement of the bolt?

A

Elongation

321
Q

To prevent plumb wires from swaying and twisting, the finned weights should be immersed in pails of?

A

Oil

322
Q

Check commutator _____ with a dial indicator rather than by visual observation.

A

Runout

323
Q

Various instruments and relays and their associated equipment, wiring, piping and conduit should be carefully installed, making sure that it does?

A

No short Circuit the

bearing insulation

324
Q

The rotating parts of the machine must be in ____ balance and may require the addition of weights to the rotor.

A

Dynamic

325
Q

Before connecting the generator to the power system check?

A

Phase sequence 

326
Q

If an operational check of the shaft runout is required, make it after the generator?

A

Is operating under full load

327
Q

In planning a major overhaul of a hydroelectric unit, one of the best sources of information is?

A

Maintenance records

328
Q

Determining the condition of the equipment should be done by performing a thorough inspection of the unit?

A

6-12 months before planned overhaul

329
Q

A list of _____ for all of the machines components should be made from the drawing information.

A

Weights

330
Q

If substantial welding is needed, the a __________ for the required repairs should be written and distributed to all the personnel that will be involved in the welding.

A

Welding procedure

331
Q

Units with replaceable seal rings should have a ______ onsite.

A

Spare set

332
Q

Shaft runout readings, bearing temperatures, pressures and permanent magnet generator (PMG) voltages are all part oF?

A

Pre shutdown readings

333
Q

Preteardown readings include?

A

Shaft alignment readings, guide bearing clearance, seal ring clearance, and generator air Gap

334
Q

To make sure parts are installed in exactly the same position from which they are removed, they should be ________ prior to removal

A

Match marked

335
Q

The rigging to lift the thrust block should include a ______ so that the block can be kept level to prevent binding when it is lifted off the shaft.

A

Turnbuckles

336
Q

After removing thrust and guide bearings, minor scratches and even some deep gouges can be adequately repaired by ____ the high spots from the babbitt surface.

A

Scraping

337
Q

In most cases the repair of ___ damage can be accomplished much more effectively with the runner removed from the turbine pit as the runner can be positioned for easier access.

A

Cavitation

338
Q

Where an overlay of a dissimilar materials is being used such as stainless steel over mild steel ,enough material should be removed to allow at least ___ weld passes to be made.

A

Three

339
Q

The interior bore of the packing box can be built up with ___ ___ as long as the box is structurally sound.

A

Epoxy coating

340
Q

Bearing cooling coils should be thoroughly inspected and _______tested.

A

Hydrostatically

341
Q

To fin the units center, the upper bridge and headcover should be installed after all the _______ parts have been removed. A _____ wire should be hung through the unit and reference measurements taken from the stator, the turbine bearing housing, the packing box bore, and to trammel points in the draft tube

A

Rotating; single

342
Q

Dowels have a very ___ fit to prevent the components from shifting once the part is positioned.

A

Tight

343
Q

When doweled components are moved during the alignment process following the overhaul of a unit _______, is necessary

A

Redoweling

344
Q

A more accurate method of measuring the preload of a coupling bolt is to measure the amount the bolt ___ as the nut is tightened.

A

Stretches

345
Q

When aligning a unit, it is important to make the bearing centers all ____, the shaft must be perfectly plumb. This can be accomplished by installing the turbine bearing and shimming the shaft to center in the _____ bearing(s)

A

Concentric; Turbine

346
Q

When setting clearances on upper and lower guide segment show bearings, install a feeler gauge to check clearance by?

A

Inserting the feeler gauge so that it extends all the way through the bearing

347
Q

When working on wicket gate adjustment the amount the servomotor travels after the gates contact each other is referred to as the?

A

Squeeze

348
Q

There should be ___ leakage upon the initial startup after the installation of new turbine shaft packing. The packing gland should be ___ evenly and in small steps until the leakage is reduced sufficiently.

A

Generous; tightened

349
Q

A very thorough inspection of the ___ ____ and the ___ ____ should be made to check for any bolts, nuts, tools, etc.

A

Generator housing; spiral case

350
Q

to prevent the damage tat could occur from circulating currents passing through them the following are insulated from the frame and should be checked with an ohmmeter prior to startup.

A

Upper guide bearing, Thrust bearing, PMG

351
Q

Operational readings should be taken once the unit has been determined to operate with no problems, they include?

A

Bearing heat run, Shaft runout readings, Load rejection tests

8th Six Months (1 decks)

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