Answer / iamdon

The function of a transformer is to transform level of
current and voltage from SOURCE to LOAD side while
maintaining the same frequency.

The ONLY CRITERIAON which govern the choice of primary and
secondary is as follows...

Primary side:Where source of power is connected.
Secondary side:Where the load is connected.

Primary and secondary are NEVER BE SELECTED on the
following bases
1)Voltage rating
2)Number of turns

Author:arbelectbit@yahoo.com

Answer / dilip dixit

We choose transformer primary & secondary on following
basis:-
1.input voltage of transformer
2. require out put voltage of transformer.
3.reguire output current of transformer.

why battery set is required for D.G.set?

7 Answers  

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1.what is surge 2.what is lightning 3.what is switching 4.difference between surge,lightning,switching used in power system 4.definition of surgearrestor,lightningarrestor 5.adv and disadv of surgearrestor,lightningarrestor 6.uses and purpose of surgearrestorand lightning arrestor 7.block dia of surge arrestor 8.blockdiagram of lightning arrestor 9.operation and working of surge arrestor and lightning arrestor 10.basic formula of surgearrestor and lightning arrestor 11.basic diagram of surge arrestor and lightning arrestor

1 Answers   Crompton Greaves, Framo, L&T,

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Brief function of stepper motor

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what is the use of Reactive power

2 Answers  

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Earth bits close or open. Which is correct

0 Answers  

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why generaters need four earthings

5 Answers   Sasken,

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Can we perform parallel operation of two transformers when one transformer on load?

3 Answers  

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No load efficiency of transformer is ___________ than full load efficiency

2 Answers   PGCET,

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WHAT CAUSED THRESHOLD VOLTAGE TO EXIST?

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why not starting switch first connect in direct on line starter?????

0 Answers  

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What is the automatic voltage regulator with servomotor?

0 Answers   Simbhaoli Sugars,

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We have drive feeding an output contactor for a 5000 hp motor @ 5kV application. The motor FLA is 629amps x 1.25% service factor = 786.25 amps The cable that we current have in place between the drive and the output contactor is 350kcmil- MV-105 (parallel cables). Per the NEC table 310.60 (C) (69). This show the cable ampacity is at 615 amps per cable for a rating of 1230 amps. We have derated the cable for the cable tray and the multiple cables application and our calculations show that after the correction factor factor we are at 922amps. 1230 amps x .75% correction factor factor = 922.5 amps. The customer is driving us to then use another safety factor of .25% off of the already derated cable. Can you please provide a longhand calculation for your solution on this application?

0 Answers   Siemens,

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