Table
5
Analysis
and
troubleshooting
of
faults
No
.
Faults
Cause
analysis
Solutions
1
Load
equipment
is
turned
on
,
but
the
controller
still
displays
undercurrent
“≡
1”
1
.
The
sampling
current
is
smaller
than
150
ｍ
A
or
the
secondary
circuit
of
the
current
transformer
is
open;
2
.
Fault
exists
in
the
current
transformer
or
the
controller
.
1
.
Check
if
the
secondary
circuit
of
the
sampling
current
transformer
is
open;
2
.
If
the
measured
IS1
and
IS2
sampling
currents
are
bigger
than
200
ｍ
A
,
replace
the
controller
.
2
Sometimes
the
controller
displays“
≡
0”
Current
transformer
sampling
current
is
bigger
than
6
.
0A
,
which
means
the
selected
sampling
current
transformer
ratio
is
too
small
.
Select
CT
based
on
the
primary
current
of
current
transformer
is
larger
than
load
current
.
3
Controller
always
displays
“≡
U”
or
voltage
value
1
.
Undervoltage
or
overvoltage
alarm
,
display
this
code;
2
.
Product
fault
Test
voltage
before
increasing
set
overvoltage
threshold
.
If
the
increase
is
invalid
,
replace
the
product
.
4
The
displayed
power
factor
keeps
changing
,
or
the
leading
and
lagging
indicator
keep
switching
.
1
.
Load
is
relatively
low
and
sampling
current
is
smaller
than
200mA;
2
.
Caused
by
frequent
load
change
,
such
as
electric
welding
machine
,
spot
-
welder
,
rolling
mill
,
pressing
machine
,
hauling
equipment;
3
.
Electrical
load
is
not
stable;
transformer
load
rate
is
relatively
low
.
1
.
Turn
on
motor
load
and
observe
the
display
of
the
controller;
2
.
Select
dynamic
reactive
power
compensation
equipment
for
fast
changing
load;3
.
Select
controller
that
uses
non
-
isometric
optimal
switching
,
such
as
NWK1
-
GR
liquid
crystal
controller
.
5
After
adding
capacitors
,
the
power
factor
remains
almost
the
same
.
The
installation
position
of
the
current
transformer
is
wrong;
the
primary
current
is
not
included
in
the
cabinet
.
Take
total
current
:
sampling
current
=
load
current
+
capacitor
current
,
which
means
the
primary
line
of
the
cabinet
is
connected
after
the
sampling
transformer
.
6
No
matter
what
load
,
the
controller
always
displays
leading
,
the
power
factor
is
negative
,
and
the
system
does
not
operate
automatically
.
1
.
Wrong
sampling
phase
sequence
,
such
as
phase
A
for
current
,
and
phase
AB
for
voltage;
2
.
There
is
equipment
such
as
frequency
converter
or
rectifier
installed
at
load
end
,
which
causes
harmonic
interference
.
1
.
Determine
sampling
phase
sequence
according
to
7
.
3
.
4;
2
.
Select
NWK1
-
GR
liquid
crystal
controller
with
stronger
anti
-
harmonic
interference
capability
.
7
Capacitor
switching
is
too
frequent
1
.
Fast
change
of
load
current
,
the
set
delay
time
is
shorter
than
10s;
2
.
The
set
target
power
factor
is
too
low;
3
.
The
set
reactive
power
threshold
is
too
low
.
1
.
The
set
delay
time
is
longer
than
30s;
2
.
Increase
target
power
factor;
3
.
Increase
reactive
power
threshold
properly
.
8
The
displayed
power
factor
is
lower
than
0
.
90
,
but
no
capacitor
is
added
automatically
.
1
.
Load
is
relatively
low
,
the
required
reactive
power
Qs
is
smaller
than
set
value
of
F
-
1
reactive
power
threshold;
2
.
The
set
transformer
ratio
is
too
small
.
1
.
Recommend
to
replace
with
2
groups
of
capacitors
with
smaller
capacity;
2
.
Set
transformer
ratio
correctly;
9
The
controller
displays
garbage
characters
or
the
controller
is
crashed
.
1
.
Abnormalities
such
as
lightning
strike;
2
.
Electromagnetic
interference
。
Disconnect
the
power
and
restart
the
machine
.
If
the
problem
occurs
repeatedly
,
replace
the
product
.
JKF8 SeriesSmart Low-Voltage Reactive Power Compensation Controller
08
