Answer / virendra ku mallah

Grafite For Lubrication Carbon for current collection
purpose.

Answer / sahil joseph

According to the periodic table carbon lies in the list of
semiconductor having valency of 4 thus semiconductors have
the property that with increase in temp. their resistance
decreases. Thus when carbon brushes rub against the commutator
due to friction their temp. increases and resistance falls.
Thus they are used for collection of current in DC machines.
In AC systems slip rings are used.

Answer / karthik raman.b

it has good peripheral speed and current density, self lubricating

Answer / prasad

THE PURPOSE OF CARBON BRUSHES ARE TO POLISHING THE SURFACE
OF THE COMMUTATOR AND TO REDUCE THE REACTENCE AT THE
COMMUTATOR.

Answer / guest

carbon is hard material compared to graphiate so it will
give a stainsail strength of graphite at the time of full
load runing condition.and graphite use for the just collect
the current and passing.

Answer / vinod kumar t

this wil reduce th sparking in the commutator

In our factory there is one no. of Series trip HT 6KV OCB. 1. Is it possible to measure CT out put current by 440V Clamp meter? The measurement is required for knowing the exact value of current in CT secondary to set up protection for transformers. 2. plase forward the single line diagram of AMF panel?

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