when we have to use UPF wattmeter and LPF wattmeter?
what is the difference between UPF and LPF wattmeter in
terms of construction?
Answer Posted / k .balaji singh
As we know the difference between upf and lpf as for resistive loads we use upf as resistive loads are which rise in temperature while passing current in electrical and in mechanical the break drum is a resistive load so while coming to inductive load which we use lpf low power factor wattemeter as inductive loads as inductor which does not draw that much current comare to resistor.
| Is This Answer Correct ? | 0 Yes | 0 No |
Post New Answer View All Answers
Single phase and threephase power calculation
what is meaning of sympathetic tripping with respect to relays and give the values for current carrying capacities for copper and aluminium cables from 16sq mm to 500sq mm
Q.1:What protection will be used on HT and LT side of 33/0.4 KV, MVA transformer. Indicate capacities of protective device to be used. Q.2:Which types of back-up protections are used in the power transformers? What do you understand by the term over travel in the relay? Q.3:How star and delta connected winding transformer are provided from earth fault
1. What is differential relay? How it operates? 2.How to calculate the Short Circuit Impedance in Transformer? 3.What is the alternate solution for testing of polarity by using polarity tester while its milli ammeter does not works? 4. While testing the 33KV Busbar by using Hipot kit, what should be the test voltage we have to apply? 5. What is the procedure/activities to be taken to inject the current more than 2000A by using 2000A Loading Transformer? 6. Explain how you can give the overload setting to any Motor Protection Relay for a HT motors with formula and example? 7. Why restricted earth fault protection is needed? Why can’t differential Protection is sufficient? 8. What should be the minimum and maximum ohmic value for earthing? 9. Why DC Currents are not used in transformer? 10. What is the Frequency while we step up the voltage from 220V to 11KV? Is it possible? Explain it?
What consists of 2 or more thermocouples to be connented series?
Why we are using Isolation Power Transformer inplace of commercial power transformer? What's the difference between them?
what are different types of electrical windings? i know the distributed winding ,concentrated winding etc but i want some detailed information, in what condition we will use distributed,concentrated windings what are the difference between them which is best, how induced emf changes by using different types of windings 20 hours ago - 1 week left to answer
Why squirrel cage motor can only use with low starting loads ?
Why is it prefer to initiate circuit breaker failure by "86" lockout relay not by "94" tripping relay ?!
can u describe the method used for protection of transmission line.
What is transmittance?
Transformer diagram mention each parts ?
What is measurement?
is it value of power factor is more than unit. whats effects in the source supply
why ups rating in kva? and why ups are in parellel?.why isolation transformer is used in ups?