Answer / rajeshsan

Brushes with metal will lead arc and more wear & tear, Hence for large rating we will use carbon brushes. And for toy motor and very small motor use metal brushes.

Answer / mohanavel.u ,marg ltd

The carbon brushes are having the self lubricating capacity
and if metal is used it will lead to more wear and tear
produces spark and damage the armature.

Answer / pavan msh

brushes used in dc machines are mostly made of carbon bcz carbon is of low cost and also a good conductor

( Re: WHAT SHOULD BE THE RATING OF MCCB FOR 415V,3Ph,50KVAR CAPACITOR BANK Answer # 1 The capacitor current would be kvar x 1000 / (415 x sqrt3). This would be 70a approx. The MCCB selected should have *atleast 1.4 times this current i.e. 1.4 x 70= 98. So you should choose at least 100 A mccb.) regarding to this answer,i would like to know why the current have to times 1.4 to get the right amphere for the mccb.hows the formula to get the 1.4??tq

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What is an automatic controller?

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