Answer / k,prakashchandra

As the pf is very low, one of the 3 watt meters will show
negative reading

Answer / natchi

In this test, we use two single phase wattmeters or one 3phase wattmeter, during test one of the 1phase wattmeter reads positive value and other one reads negative value of 3 phase power.

but in usage of 3 phase wattmeter gives directly the whole power of 3 phase supply.

what happens to the supply voltage if there is any change in frequency?

1 Answers   Gridco,

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what is the name of transformer oil.

15 Answers  

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testing of transformer

1 Answers   Vijai Electricals,

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why we use carbon brush in exciter&genrator?

5 Answers   ABB, SMC,

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why the generating voltage in India is 11kV or why is it be transmitted as multiples of 11

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why do we provide metallic enclosure to bus duct and then ground it?

1 Answers  

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how to calculate the KVAr for an motor for improving the PF

3 Answers  

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i have a 4 Mva transformer 34.5 kv / 480-277 v and i used 2 parallel 3200 amp bus duct for the secondary feeder using 3 ply of bus bar ( 3/8" x 5" ) as a common where the flexible link terminated and 6300 amps breaker for the main, the lower bus duct reaches 70 degrees and the upper bus duct reaches 55 degrees when i used thermal scanner. why the temperature is not balance when the load reaches 3600 amps.

0 Answers   SCM,

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how to differentiate a mpcb,mcb with a contactor? Explain their working operation

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will a transformer work when pulsating dc id applied to its primary?? what will be the result??

2 Answers   cemp,

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how to select the cables based on amps ratings ? how to calculate the amps and how to select the cable size

1 Answers   JV Electricals,

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