why do we use LPF wattmeter not UPF in the experiment of no load and blocked rotor test of 3phase slipring induction motor?

Answer Posted / pritish

in case of no load test, the supply voltage is rated but the current drawn by the induction motor is very less; no load current, which produces only the core loss of the stator and some mechanical loss.  in no load condition, the angle between V and I are high as a factor the pf will be less. hence to calculate the pf accurately LPF wattmeter is used. during loaded condition current increases and angle decreases hence pf increases.

any more clarification regarding this should be sent to pritish.nath@gmail.com

Is This Answer Correct ?    36 Yes 3 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

If 22 KV HT line, Current transformer is 25/5 then how to calculate multiplying factor.

602


At what speed an electric car can run with 2 HP motor of weighing 400 kg?

1305


Keywords: Die, Card, Coin, B/N 2 To 12

790


How can we calculate strength of copper hich is supplying electric power to heater and in it hold the heater also and what r all types of forces which is acting on it...

1473


At what factor resistance r of a conductor depends?

636






How to do maintenance of transformer feeder.

1341


A 7 storey building has a floor area of 35,000sq.ft on each storey. On the ground floor 11KV electrical sub-station is to be erected. A load of 3kw for every 400sq.ft (p.f is 0.8) is proposed for each floor. fire pump 7.5hp, water pump 5hp, lift 2 nos, each 10hp and 20shop load of each shop is 5kw. calculate a. load each floor b. total load of building c. L.T feeders for aech floor and from transformer to main. d. distribution diagram e. capacity of sub-station/capacitor bank f. line diagram

2368


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

1644


state working of halogen lamp?

1353


hi there i am highly enthusiastic about discussing electrical concepts , and hence i wud lyk to invit al do intrested to join me at gtalk and hav a dscussun of the concepts , ad me as a freind . my email id is rakesh.2k99@gmail.com

1629


what is mean by restructuring power system?

1537


How to do cable sizing calculation for 750 A Neutral Earthing resistor for 33kv. the 33kv cable going to swbd. is 630mm2 3 runs.

4318


Give me the calculation steps to design an electromagnet to be work in 230V 50 Hz AC Supply. Also give force that is created by that electromagnet when it gets energized.

1809


what happen when we add mentos in cold drink?& why?

1547


how commomn gate triggering is given for TRIAC ? other thyristor wont be efffected?

1901