1. what is the power factor and whatis his losses
2. what is the working procedure of 51RNB AND 87 relay
- 3 Answers
- 5075 Views
- ABB, I also Faced
- E-Mail Answers
Answer Posted / arun_sekar_1986
1.Power Factor is defined as the cosine angle between
voltage and current.
From Power triangle cosine angle is defined as the adjacent
by opposite side.
ie., cos angle=kW/kVA
2. 51-AC Time Overcurrent Relay is a relay with either a
definite or inverse time characteristic that functions
when the current in an ac circuit exceed a predetermined
value.
87-Differential Protective Relay is a protective relay that
functions on a percentage or phase angle or other
quantitative difference of two currents or of some other
electrical quantities.
| Is This Answer Correct ? | 4 Yes | 1 No |
Post New Answer View All Answers
What is time response of the control system?
why ht cable end termination don't have a gland?
when ac current flows thru d coil of a contactr,it energizes,magnetic field attracts d contact of the coil...nw wont dt ac current in d contct induce current back on to d coil thru mutual inductance leading to high currnt in d coil
Help need in transformer !? Hello Friends The parameters of 2300/230 v 50hz t/f is R1=0.286 ohm R`2=0.319 ohm Rc=240 ohm X1=0.73 ohm X`2=0.73 ohm Xm=49.2 ohm Secondary Load impedance ZL=0.387+J0.29 solve the exact equivalent circuit with normal voltage across primery.. I know every thing but i cant find CURRENT I1=? and I`2=? Please help me give solution or only Formula please please...
In the N-series schneider reclosers. What is the difference between current during fault time and current at tripping? This appears in the Event log in an event of a trip out.
what are the ''pitting rings''and how cn they be controlled in a series generator
why Lightening Arrester Probe sharp at Top of telecom tower.
why we permissive overreach in distance protection.where it is applicable to use in long r short lines
advantage of motor design on higher power factor . normally motors are designed for .8 power factor. what is advantage of designing at .88 power factor
what is the difference between gas group b and gas group c electrical equipment construction wise?
why the name trunking bus PT
Can u explain : what is supply for train (whether a,c or d.c ).I know that supply is 25000v a.c .But there is rumour that supply is D.C. And also explain how lights and fans inside the trains are working ,and what type of motors are used in trains whether D.C motors or induction motors .If d.c motor, how it gets supply.If traction motors are used then what are traction motors and its functions and how it differs from other motors and also explain about locomotive . y d.c series motor in train.train wheels r driven by D.C shunt motor ,at what voltage,and at what speed. please reply..............
what is the total power generation in india?
we have require a Motor (1500kW, 6.6kV, 50Hz) which shall operate at 1500rpm during 30min and after it shall run on 500rpm during 15min. The same cycle shall be repetitive during the whole working days. Which method is best and economic to achieve such type of task. VFD, VVFD, Pole changing motor etc.
What is the function of capacitor in electrical circuits?
