Test Review

Question 1

What is the definition of a governor?

Answer 1

An automatic attachment for controlling speed

Question 2

What does the governor oil system consist of?

Answer 2

• pump
• sump tank
• oil piping
• pressure tank

Question 3

What are 4 visual signs of oil deterioration?

Answer 3

• varnish
• sludge
• dark cloudy color
• dirty filter

Question 4

If the load on the turbine is suddenly dropped, what happens to the speed of the governor ballhead?

Answer 4

Increases instantly

Question 5

If the governor is regulating a single generator with its own load, will it have speed drop?

Answer 5

No

Question 6

Where does a governor get its sensitivity?

Answer 6

Flyballs

Question 7

A compensating dashpot is a device used to achieve ______ of the governing unit.

Answer 7

Stability

Question 8

What is the function of the pilot valve in a hydraulic governor?

Answer 8

Provides hydraulic force to the relay valve

Question 9

True or False:

A generator with 5% speed drop will sense a change in load.

Answer 9

True

Question 10

What does the dashpot consist of?

Answer 10

Needle valve and two pistons

Question 11

List four safety devices in a hydraulic turbine governor system.

Answer 11

• overspeed
• broken belt device
• low oil pressure switch
• nozzle deflector

Question 12

What is the purpose of the vibrating disks?

Answer 12

stability and lubrication

Question 13

The auxiliary valve is used in a hydraulic governor system to…

Answer 13

Manually operate the gate servomotor

Question 14

What is the main function of the PMG?

Answer 14

To supply electric power to operate the ballhead motor

Question 15

Where is the speeder spring located?

Answer 15

Next to the flyballs

Question 16

What is the function of the restoring mechanism in a hydraulic governor system?

Answer 16

To recenter the pilot and relay valves

Question 17

What is the gate limit device used for?

Answer 17

• control the opening of the gates during startup
• prevent overtravel
• control gate position from a remote location

Question 18

True or False:

If the needle valve in the dashpot has been adjust correctly it will allow the small plunger to recenter in the same interval that the speed drifts back to normal.

Answer 18

True

Question 19

True or False:

The governor ballhead must turn at the same RPM as the PMG.

Answer 19

False

Question 20

What position the relay valve and how does it do it?

Answer 20

The pilot valve hydraulically positions the relay valve

Question 21

As a hydraulic governor system functions, the relay valve plunger moves downward and the pilot valve restoring linkage moves the pilot valve bushing downward until…

Answer 21

the ports in the bushing are closed

Question 22

Names four qualities of good governor oil.

Answer 22

• lubricates
• does not precipitate solids
• does not break down
• dissipates air

Question 23

True or False:

The ballhead is a speed sensing device mechanically connected to the relay valve that changes the speed of the unit.

Answer 23

False

Question 24

True or False:

The needle valve in the dashpot provides a means of adjusting the speed or movement of the wicket gate.

Answer 24

False

Question 25

The servomotor is a ______ cylinder

Answer 25

Double-acting

Question 26

If the system is sluggish in response to speed changes, what is the issue?

Answer 26

The spring on the compensating dashpot is too tight.

Question 27

True or False:

A floating lever is a lever with several independent fulcrum, none of which are fixed.

Answer 27

True

Question 28

The compensating dashpot provides ______ restoring.

Answer 28

temporary

Question 29

Name four basic parts of a simple governor.

Answer 29

Flyballs, speed changer, oil pressure system, servomotor, pilot valve, relay valve, restoring mechanism, gate limit device