baring gear

APPROVAL ISSUE

Course 234 - Turbine and Auxiliaries - Module Nine

NOlES & REFERENCES

Module 234-9

THE TURNING GEAR
OBJECTIVES:
After completing this module you will be able. to:

9.1

a)

For each of the turbine operating states listed below, state the purpose(s) of the turning gear operation:
i)

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ii)

b)

During turbine stanup (2);
While shutting down the turbine (I).

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For each of the operating states listed in point (a), describe turning gear operation, addressing the following points:
i)

3

(startup),

and 4-5 (shtdown)

When the turning gear motor is started up / sbut down;

ii)

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When the turning gear is engaged to / disengaged from the torbine generator rotor;

iii) The reason why during turbine runup the turning gear mo-

tor continues running for some time after the turning gear has disengaged from the turbine genemtor rotor; iv) The reason why during turbine rundown the turning gear motor is started up some time before the turning gear is actually needed to rotate the turbine generator rotor.
c)

For each of the operating states listed below, descnbe the ad-

verse consequences/operating concerns caused by failure to tum the turbine generator rotor as required:
i)

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ii)

9.2

During turbine stanup (2);
While shutting down the turbine (3).

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Explain the major operational concern caused by excessive use of the turning gear.

9.3

a)

i)

State the general operator action that should be taken, to protect the turbine, if the turning gear fails to start during a

turbine rundown. ii) Explain how this action protects the turbine.

iii) Describe three alternate methods of turning the turbine rotor

that can be used under these operating circumstances.

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APPROVAL ISSUE

Course 234 - Turbine and Auxiliaries - Module Nine

NOTES & REFERENCES

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