Allis Chaimers

Question 1

Although machines may be extremely large, _________________ must be maintained in fit and alignment of various parts.

Answer 1

Close tolerances

Question 2

Suspended type machines have the thrust bearing and an upper guide bearing located where?

Answer 2

Above the rotor

Question 3

Larger low speed machines use what to secure the poles to the rim?

Answer 3

Driven tapered keys

Question 4

Why is a hollow shaft required in an adjustable blade pump or propeller type turbine?

Answer 4

So that oil pipes can be carried through the shaft from the oil head at the top and of the unit to the turbine servomotor

Question 5

The designated oil level is usually about one-third the length of the bearing above its lower end for what system?

Answer 5

Guide bearing lubrication

Question 6

Brakes are usually operated by compressed air at ___________ psi. Brakes may also be used as jacks. When jacking they are operated by oil pressure of ________ to _______ psi.

Answer 6

75-100 psi
1000-3500 psi

Question 7

High pressure bearing lubrication is frequently used to…

Answer 7

Reduce the breakaway torque

Question 8

The high pressure system has a pressure switch that prevents starting of the machine until the high-pressure pump assembly is up to pressure, approximately ________ psi.

Answer 8

1000 psi

Question 9

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

Answer 9

1/4 to 3/4 inch

Question 10

Provide fins on the plumb bob and allow it to hang in a Pail of heavy oil to damp any swings. Protect the plumb line from all _________.

Answer 10

Strong air currents

Question 11

Electric welding on any part of the machine is a serious hazard to bearings. A bearing surface can be _____________ if welding current passes across it.

Answer 11

Damaged rapidly

Question 12

If possibly all electric welding especially on the rotating element should be done when?

Answer 12

Before the bearings are assembled

Question 13

How should you test the cooling coil for water tightness?

Answer 13

With the oil reservoir empty and the water pressure raised 50% above normal if possible

Question 14

A bearing can easily be damaged by a particle of lint or dirt. Consequently, precautions must be taken during assembly of the bearing to avoid…

Answer 14

The presence of dust and dirt

Question 15

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

Answer 15

Proper elevation and clearance

Question 16

Bearings and other parts such as instrument elements, Kaplan features, conduit piping etc. which make contact directly or indirectly, with the shaft above the rotor are usually…

Answer 16

Insulated

Question 17

Check this insulation with a 500 volt insulation resistance meter and if the resistance is less than 20,000 ohms ….

Answer 17

Inspect the insulation and make the necessary corrections.

Question 18

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

Answer 18

Prevent distortion

Question 19

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

Answer 19

Elongation

Question 20

Use steel music wire plumb lines with heavy finned weights , immersed in pails of oil to prevent?

Answer 20

Wires from swaying and twisting

Question 21

Check commutator runout with a?

Answer 21

Dial indicator rather than by visual observations

Question 22

Various instruments and relays and its associated wiring must be carefully installed making sure that it does not…

Answer 22

Short-circuit the bearing insulation

Question 23

The rotating parts of the machine must be in dynamic balance. This may require the addition of?

Answer 23

Balance weights to the rotor

Question 24

Before connecting the generator to the power system check?

Answer 24

Phase sequence of the generator

Question 25

If an operation check of the shaft runout is required make it as described in the appendix after the generator…

Answer 25

Is operating under full load