LV Network Calculations and Use of Amtech

8/9/2019 LV Network Calculations and Use of Amtech

1/38

LV Network Calculations& Use of Amtech

Jyothimon Abraham,Msc,B.E

Senior Electrical Engineer,B.K Gulf,Dubai


2/38

Not very simle !or"e" as DE#A$ADE#A etc.

But lot of ne! terminologies

%evelation of Design &rocess

Kno!ing many stan"ar"s hels to 'no! !here !estan" right no!

Soun" Engineering Decisions are a result of 'no!ingof (omonents involve", )n"erstan"ing of relate"stan"ar"s an" e*eriencing of rocess involve"

WHY BS767 !S!"#$%AN


3/38

(AB+E S-NG /0+1AGE D%0& (A+()+A10NS

S20%1 (%()1 EA%12 3A)+1 S1)DES

DS(%MNA10N S1)DES %E+A4 SE1NG

AM1E(2 &%A(1(E SESS0N

$#!CS C$V'%'(


4/38

CABLE SIZING

CALCULATIONSBased on BS7671 & DEWA Regulations


5/38

HEATING EFFECT ON CABLES

Concept of Thermal Equilibrium

Heat energ generated b Cable ! Heat

energ dissipated b cable into the

en"iornment


6/38

CORRECTION FACTORS-BASED

ON ERA STUDIES

Cable derating is done for a"oiding cables sub#ect to

Thermal stress$

Cables on %ree ir

mbient Temperature %actor 'Ca(

)rouping %actor 'Cg(

*+ecide the method of ,nstallation from TB-E*./

Thermal ,nsulation %actor'Ci(

Cables 0nder )round +erating factors are a"ailable for +epth of Burial

%or )round Temperature %or )round Thermal

Resisti"it b ,EC$ mtech allo2 user defined

+erating %actors to be incorporated$


7/38

DETERMINATION OF CABLE SIZE

+esign Current ',b(

3ominal Current',n ( of the 4rotecti"e +e"ice

Tabulated Current Carring Capacit',t (

Criterion ,n ,b


8/38

TABLE LOOK UP


9/38

AMTECH CABLE INTERFACE


10/38

VOLTAGE DROP CALCULATIONS

*Correction for perating Temperatures

*Correction for -oad 4o2er %actors

*Correction for Temperature & -oad 4o2er

%actors


11/38

AMTECH APPROACH TO V.D


12/38

VOLTAGE DROP INTERFACES


13/38

MOTOR STARTING VOLTAGE

DROP

oltage*sensiti"e de"ices such as dri"es 2ill

drop out if "oltage drop e8ceeds 19:$

;


14/38

THANK YOU

estions


15/38

EA%12 3A)+1S20%1 (%()1S1)DESBS 5657 ,E(

689:5,BS5:;8


16/38

10)(2 /0+1AGE ()%/E ;8mA for < sec is

safe as er touch

voltage curve s D.( Shoc' 0%

A.( Shoc' high=

(omaring 1ouch

voltage curves ,".cgets "angerous at7>8mA,7sec.


17/38

EA%12 3A)+1

1E%MN0+0G4 10)(2 /0+1AGE?Direct Shoc' Situation@

)t

)t


18/38

Sulemtary Bon"ing )t

1his metho" is calle" Earthe" EFuiotentialBon"ing Automatic Disconnection ofsulyCEEBAD0S


19/38

SA3E DS(0NNE(10N 1ME

8.: secon"s for small o!er outlets an"nal sub circuits not e*cee"ing 6;A

> secon"s for sub mains an" nal subcircuits fee"ing *e" eFuiment


20/38

EA%12 +00& M&EDAN(E


21/38

S20%1 (%()1 1E%MN0+G4 &%0S&E(1/E S20%1

(%()1 ()%%EN1

&EAK 3A)+1 ()%%EN1#12S1AND

(&D B%EAKNG(A&A(14

NS1AN1ENE0)S 1%&

()%%EN1H (AS(ADE %A1ED

B%EAKNG (A&A(14


22/38

&revention Arc 3lash 2aIar"

)se of &&E


23/38

ADABA1( (2E(K K


24/38

me"ance Diagrams


25/38

ILB)S (0N(E&1


26/38

than' you

estions


27/38

(!SC%!"!NA!$NSU(!'S & %'LAYS'!N)


28/38

'L'C%$N!C %!#CHA%'C'%S!CS $* B%'A+'%

2o! many (ycles!ithstan" anEFuiment canEn"ure=


29/38

)%$UN( CHA%AC'%!S!CS $*B%'A+'%


30/38

(!SC%!"!NA!$N L!"!


31/38

C$NC'# $* !"' )%A(!N)

• belo! 8.8> sec or three cycles on the time a*is isthe instantaneous tri function

• Short time settings cover the time range from8.8> to 8.> sec Cthree to ;8 cycles.

• +ong time settings cover the time range from 8.>to 7888 sec.

• Ma* tri time of


32/38

Conce,t of -$N!N)


33/38

Y#'S $* (!SC%!"!NA!$N

• 1ime Discrimination

• Energy Discrimination

• -one Selective Discrimnation


34/38

A"'CH (!SC%!"!NA!$N!N'%*AC'


35/38

A"'CH %'LAY S'!N)!N'%*AC'


36/38

#'%*'C (!SC%!"!NA!$N


37/38

-$N' S'L'C!V'!N'%L$C+!N)


38/38

HAN+ Y$U

Questions

Documents

LV Network Calculations and Use of Amtech