Page 86 - Industrial Power Engineering and Applications Handbook

Duties of induction motors 3/67
Relevant Standards
It c Rile, IS R\
- - - - -
60033- I / 1996 Rotating electrical machine\ 31 22/ 1 992 BSEN 60014 11995
R'iting and performance 32511996
60072- I /I 99 I Dimenuons md output wries tor rotating electrical 1 23 I / I99 I BS 5000-10/19XY
machine\ Frame number 56 to 400 and tlange B\ 4999 14111987
number 55 to 1080
60072 21 IO90 Dinien\ion\ and output \erie\ tor rotating electrical I21 I /I 991 BT 5000 lO/19X9
machine\ Frdme number 355 to 1000 and flange BS 3999-101/1987
number I I XO to 2360
60072-?/l993 Diinensions and output \erie\ tor rotating electrical machine\ 996/1991 BS 5000- I I / 19x9
Sindll built-in moton Flange number BF 10 to BF50
~ ~
Related US Standards ANSI/NEMA and IEEE
- ~- ~~ ~~ - ~
NE I\.lA/MG - L/ 1993 Motor\ and generator\ ratings, con\truction testing. and performance
NbhlA/MG-2/198Y Satety Standard\ (enclosure\) for conctruction and guide tor \election. in\tCillation and use ot rotating machine\
NEMAfilG 10119Y4 Energy man,igement guide tor \eleLtion and u\e 01 three-phdse nio1or\
-_____ _____~
~ ~-
No re \
I In the table\ of relevant Standards in this book while the latest editions of the standards are probided. it is possible that rebised editions
have become available. With the adlance\ of technology and/or its application, the updating of standards is a continuous pi-ocesn by
diflerent standards organizations. It is therefore advisable that for more authentic references. readers should consult the relevant
organiration\ for the latest version of a standard.
7 Sonic of the BS or IS standards mentioned against IEC may not be identical.
3 The yur noted apain\t each standard may also refer to the year of its last amendment and not nece\\arily the year of publication

List of formulae used K = a factor that depends upon the type of relay (generally
1 to 1.2)
I, = actual current
Factor of inertia
Exponential heating on a hot start
(3.1) 0,, =I; +(I; -Ii)(I -c.-"T) (3.4)
S, = temperature rise on a hot start above 0:, after t hour
GD;, = M.1 of motor in "C.
GDf = M.1 of load at motor speed = 0, - 0,
M.1 = moment of interia Io = initial current at which the machine was operating
I, = actual cui-rent of the machine

Heating curves t = rlog, I,? - If (3.5)
~
If - kl,'
Exponential heating on a cold start
Adiabatic heating on a cold start
e, = 0,J 1 - P) (3.2)
8, = Oc - e:, = If . I (3.6)
O, = temperature rise on a cold start above 0, after t s
hours in "C.
= 8, - 0, Adiabatic heating on a hot start
0, = end temperature of the machine in "C after time t 0,, = 0, - 0, = 1; i - If )tlr (3.7)
(If
O,, = ambient temperature in OC
e,,, = steady-state temperature rise at full load in "C
t = tripping time of the relay in hours Cooling curves
r = heating or thermal time constant in hours Exponential temperature fall when I, = 0
K. If If (I ~ e I") (3.3) 0 = 0 , (3.8)
=
in
I, = rated current of the motor in A f = cooling time constant in hours