why neutral and earth should not be connected on 3 phase 440v/50c/s supply at

why neutral and earth should not be connected on 3 phase
440v/50c/s supply at consumer side. where as on
25kv/ac/50c/s railway traction substation neutral and earth
will be connected and track at substation. and track will
act as neutral and earth. Reasons for this is needed
urgently

Question Posted / shivababa_1812

4 Answers
7590 Views
I also Faced
E-Mail Answers

Answers were Sorted based on User's Feedback

why neutral and earth should not be connected on 3 phase 440v/50c/s supply at consumer side. where..

Answer / nmr

IF ALL CONSUMERS EARTH ARE CONNECTED TO NEUTRAL AT EACH
CONSUMER POINT, ALL THE EARTH ELECTRODES RESISTANCES ARE
BECOMES PARALLEL ALONG WITH TRANSFORMER SECONDARY NEUTRAL-
EARTH ELECTRODES. HENCE 1/R= 1/R1+1/R2+1/R3+1/R4 ETC.,
THERE EFFECTIVE RESISTANCE IS BECOMES VERY VERY LOW. IF A
30 KVA TRANSFORMER IS THERE. THE CURRENT IL/IPHSE =
30,000/440*1.732 = 40.0 AMPS (WITH UNITY PF) THIS CCURRENT
WILL PASS THROUGH EARTHS ELECTRODES(BECAUSE ALL EARTH
RESISTANCES ARE PARALLEL AND NET RESISTANCE WILL BECOME
LESSER THAN THAT OF NEUTRAL)SO STEP POTNTIAL WILL RAISE
CAUSES ELECTRIC SHOCK TO THE PEOPLE WALKING AT NEAR
TFP/PANNEL BOARDS. IN TRACTION SUBSTATION A EARTH MAT WILL
BE PROVIDED IN THE YARD TO REDUCE THE STEP VOLTAGE NOT TO
GET SHOCK BY THE PEOPLE. OK
NMR/email; bapdada1812@gmail.com electrical engineer

Is This Answer Correct ?

3 Yes

0 No

why neutral and earth should not be connected on 3 phase 440v/50c/s supply at consumer side. where..

Answer / k.prakashchandra

Consumers earth is for connecting to metal bodies to prevent
shock . The neutral is already earthed at the TC and another
earth means extra expenditure.During earth fault ,there will
be temporary rise in voltage resulting in burning out of
potential coils of the energy meter.And if earth is
connected to neutral wire of supply after the RCCB, it will
trip as a portion of neutral current will be bypassed.

Is This Answer Correct ?

1 Yes

1 No

why neutral and earth should not be connected on 3 phase 440v/50c/s supply at consumer side. where..

Answer / jicks patel

voltage level at consumer side is generally kept low (230v
or 440v),any shocking moment should face fuse sensually.so
no more cost required like earthing.

Is This Answer Correct ?

1 Yes

2 No

why neutral and earth should not be connected on 3 phase 440v/50c/s supply at consumer side. where..

Answer / shivababa_1812

electrical engineering

Is This Answer Correct ?

1 Yes

12 No

Post New Answer

More Electrical Engineering Interview Questions

how to calculate the earth fault current

0 Answers

In a circuit the power factor was leading what will happen?

2 Answers

function of soft starter .

2 Answers

WHAT IS MEANING OF VECTOR GROUP FOR TRANSFORMER

2 Answers

what are the main components of fan?

2 Answers

why gravels is used in transformer yard?

6 Answers

why 15 kw motor winding resistance is low then 5 kw motor winding resistance?

0 Answers Baosteel,

How to find HT side and LT side(of a transformer),with the help of a voltmeter?

1 Answers Odisha Power Generation Corporation OPGC,

what is the difference in inductance and resistance.both oppose the flow of current but how.resistance having + ve power in both cycle while inductance having both power.

5 Answers

i am going to correct power factor of 1600kw induction motor,when i calculate capacitance of capacitor it is three time more in star connection than delta. if motor is star connected which connection i shall adopt for capacitors and reason for adopt this connection

0 Answers

how to calculate the knee point voltage of current transformer?

2 Answers

why we don't discuss power facter in dc?

5 Answers

For more Electrical Engineering Interview Questions Click Here