01
NWC1 Series Self-healing Low Voltage Shunt Capacitors
1
Use
Purpose
and
Application
Range
NWC1
series
self
-
healing
low
voltage
shunt
capacitors
(
hereinafter
referred
to
as
capacitors
)
are
applicable
to
power
frequency
AC
power
systems
with
rated
voltage
up
to
1
,
000V
for
power
factor
increase
,
reactive
power
loss
reduction
and
voltage
quality
improvement
.
2
Type
Key
and
Definitions
N
WC
1
L
refers
to
inductance
Phase
number
:
3
-
three
phase
,
1
-
single
phase
Rated
capacity
(
kvar
)
Rated
voltage
(
kV
)
Design
series
number
:
1
-
means
double
layer
case
Self
-
healing
low
voltage
shunt
capacitor
Group
company
code
3
.
1
Environmental
conditions
:
See
Table
2
for
ambient
air
temperature
,
relative
temperature
and
altitude
.
3
.
2
Installation
conditions
:
On
condition
that
the
safety
precautions
are
met
,
the
installation
site
should
be
free
from
hazardous
gases
and
vapors
,
conductive
or
explosive
dusts
,
and
strong
mechanical
vibration
.
3
.
3
Application
conditions
3
.
3
.
1
The
rated
voltage
of
the
capacitor
must
be
higher
than
the
voltage
of
user’s
grid
.
When
the
environmental
conditions
exceed
the
limits
in
3
.
1
,
user
must
derate
the
capacitor
by
raising
its
rated
voltage
,
otherwise
the
service
life
of
the
capacitor
can
be
significantly
shortened
after
long
-
term
overvoltage
or
overtemperature
operation
.
3
.
3
.
2
Harmonic
current
amplification
is
the
primary
cause
for
capacitor
damage
.
Common
harmonic
sources
include
:
power
electronic
equipment
,
frequency
converter
(
energy
saving
transformation
,
such
as
motor
speed
regulation
,
variable
frequency
air
conditioner
,
etc
.),
DC
rectifier
,
inverter
,
electrolytic
plating
equipment
,
electric
arc
furnace
and
intermediate
frequency
furnace
,
etc
.
See
Table
1
for
capacitor
selection
and
harmonic
suppression
measures
under
harmonic
environment
:
3
Conditions
for
Normal
Use
,
Installation
and
Transportation
,
and
Storage
Model
Harmonic
source
power
/
transformer
capacity
Harmonic
source
power
/
transformer
capacity
Harmonic
source
power
/
transformer
capacity
N
LL
≤
10
%
N
LL
≤
20
%
20
%≤
N
LL
≤
40
%
Voltage
total
harmonic
distortion
THDu
≤
3
%
3
%＜
THDu
≤
5
%
THDu
＞
5
%
Rated
voltage
of
capacitor
0
.
4kV
,
0
.
45kV
0
.
45kV
,
0
.
48kV
0
.
48kV
,
0
.
525
kV
Harmonic
suppression
measures
Not
needed
Recommend
to
use
series
reactor
7
%
Series
reactor
7
%
or
14
%
Note
:
If
harmonic
power
ratio
NLL
＞
40
%,
user
must
install
CKSG
series
reactor
or
take
harmonic
suppression
measures
.
3
.
3
.
3
.
If
detuning
low
voltage
series
reactor
is
installed
at
the
front
end
of
the
capacitor
,
the
rated
voltage
of
the
capacitor
should
be
selected
as
below
:
If
the
reactance
rate
of
the
reactor
is
6
%
or
7
%,
the
rated
voltage
of
the
capacitor
should
be
0
.
45kV
or
0
.
48kV
,
if
the
reactance
rate
of
the
reactor
is
12
%
or
14
%,
the
rated
voltage
of
the
capacitor
should
be
0
.
525kV
.
3
.
3
.
4
See
6
.
2
for
product
installation
spacing
.
We
suggest
double
the
installation
spacing
if
the
product
is
installed
above
an
altitude
of
2000
meters
.
User
should
take
effective
measures
to
ensure
good
ventilation
Table
1
Capacitor
selection
and
harmonic
suppression
measures
under
harmonic
environment
