Amtech & Manual Cable Sizing Calculation

Topics: Volt, Voltage, Power cable Pages: 19 (782 words) Published: November 6, 2012

Index

Declaration ................................................................... Error! Bookmark not defined.   Index .............................................................................................................................. 1   Cable

Sizing ................................................................................................................... 2   Objective ................................................................................................................... 2   Procedure .................................................................................................................. 2   Design

Current
(Ib) .............................................................................................. 2   Current
Carrying
Capacity
of
the
cable
(Iz): ...................................................... 3   Correct
Cable
Size: ................................................................................................ 3   Volt
drop
(Vd): ...................................................................................................... 4   Result ......................................................................................................................... 5   Conclusion ................................................................................................................. 5   Amtech

PDF .................................................................................................................. 6

Cable
Sizing

Objective

The
objective
of
the
assignment
is
to
pick
the
correct
size
of
cable
and
the
correct
protective
conductor
and
also
the
correct
protective
device
for
the
following
installation:

A
consumer
has
to
have
installed,
a
new
9kw/230v
cooker
unit
in
domestic
premises.
The
existing
eight
way
consumer
unit
houses
ISN
EN60898
MCBs/ISN
EN
61009
RCBOs
and
supplies
two
final
ring
circuits,
one
shower
circuit,
one
immersion
heater
circuit
and
two
lighting
circuits
leaving
two
spare
ways.
The
length
of
run
from
the
consumer
unit
to
the
cooker
is
approximately
28m.
The
installation
reference
method
is
method
C,
the
ambient
temperature
will
not
exceed
30̊
C
and
the
circuit
is
grouped
with
3
other
circuits.

Procedure

Design
Current
(Ib)
This
can
be
obtained
by
the
following
formula:

������������ =

������ 9000 = = 39.13������
������ 230  ×  1

������������ = 39.13

The
protective
device
(In)
that
is
to
be
used
in
this
installation
is:
1
x
ISN
EN60898
40A
MCB

Current
Carrying
Capacity
of
the
cable
(Iz):

The
current
carrying
capacity
of
the
cable
is
known
as
Iz
this
can
be
obtained
by
the
following
formula:

������������ =

������������
������������×������������

Ca
is
the
ambient
temperature
factor.
This
can
be
obtained
in
Table
A52-­‐ G1
Pg-­‐283
of
the
ETCI
Rules.
The
factor
for
this
installation
is
Ca
=
1
as
the
temperature
does...