Page 139 - Electrician - TT (Volume 2)
P. 139
ELECTRICIAN - CITS
When the alternators are synchronized, lamps 1 and 2 are bright and lamp 3 is dark. Since two of the lamps are
becoming brighter as one is dimming, it’s easier to determine the moment when the paralleling switch can be
closed. Furthermore, by observing the sequence of lamp brightness, it’s possible to tell whether the speed of the
alternator being synchronized is too slow or too fast and can be connected it.
At the moment when the two lamps are full bright and one lamp is full dark, the synchronizing switch can be
closed.
Now the both alternator are synchronized and share the load according to their ratings.
Effect of changing the field excitation and power factor
A change in the excitation of an alternator running in parallel with others effects only its KVA output it does not
effect the KW output. A change in the excitation thus effects only the power factor of its output.
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CITS : Power - Electrician & Wireman - Lesson 76-85 CITS : Power - Electrician & Wireman - Lesson 76-85
