Subject: KNB 1560 series CD
For serial connection to the mains
Date: 25.03.2014
We would like to stress ISKRA capacitors X2 – KNB series are made in accordance with all
specifications and standards required for RFI application (IEC 60384-14, UL 1283, UL 1414,
CSA C.22 No.1, CSA-E 384-14-95, CQC, GB /T14472).
Tests according to standards are made in our lab regularly.
Also inspectors from third bodies visit us and take samples for testing as prescribe in their
requirements. We have to say the results are always positive so quality of Iskra capacitors is
stable and reliable.
We assume that some customers do not use our X2 capacitors in RFI applications but in
special ones, for example application such as built-in room thermostats, counters, etc.
Due to the matter of different application, our R&D Dept. started with the project to reduce the
possibility for voltage-corrosion process, which result is decrease of capacitance, to as low
level as possible and have thus developed the CD version of capacitor series KNB 153x and
KNB 156x.
The AC voltage corrosion intensity is depended of:
- applied AC voltage level
- frequency of AC voltage
- ambient temperature
- ambient air relative humidity
We have been carrying out the internal accelerated test in our lab which simulates the similar
conditions assuming customers have in different not RFI applications.
ADVANTAGES of CD version:
-long-term capacitance stability
-no capacitance dimensions change
-cost-effective construction
Finally we would like to explain that we have to know exact data bout customer's requirements
in not RFI application. With good intention for mutual and long-term cooperation and
furthermore to be able to avoid troubles later in not RFI applications our requirement is to take
into account point 5 and 6 in ISKRA catalogue http://www.iskrasistemi.si/products/2010053111092173/2010053112561428/
and inform us about customer’s conditions in different applications.
Capacitors in CD version correspond and have all safety certificates as standard version.
Example mark of capacitor CD:
Prepared by:
Brane Požek, R&D Engineer
Andrej Dragoš, PE Kondenzatorji QM
Presentation
Film capacitors - General information
C a p a cito r
sym b o l
A capacitor is an electric device that can store electric charge which can
be used later for different useful purposes.
−Q
+Q
E
+
+
+
+
_
_
_
_
E=
d
U
d
Q = C ⋅U
U
+ −
E…electric field
Q…electric charge
C…capacity
U…voltage
d…distance between metal plates
Equivalent circuit real capacitor
Rp
Ls
Rs
s
C
Ls…inductance
Rp…parallel resistance
Rs…series resistance C….capacitance
Ls = LL+ LW
Rs = RL+ RC+ RW
Z= Impedance[Ohm]
(LL = Inductance of the leads, LW= Inductance of winding)
(RL= Resistance of leads, RC= Resistance of contacts, RW= Resistance of winding)
Film capacitors
- Performance
- Self-healing
Metallized film capacitor
Plastic film
dielectric
Performance:
stabile capacitance
higher isolation resistance
small self inductance
low dissipation factor
self-healing
Single metallized
film
Metal-sprayed
contact layer
SelfSelf-healing
The metal layer is very thin and, in case of
dielectric breakdown, the energy released
by the arc discharge in the breakdown
channel is sufficient to totally evaporate the
thin metal coating close to the channel. This
results in insulation restoring and a small
capacitance drop.
H1
I
R
K
H1
H2 I
H1, H2…
I…
R…
K…
Metal layer
Dielectric
Self-healing region
Current line
Electrode edge
Breakdown channel
Film capacitors – Designation of dielectric and type code
Type code is composed by three letters and four figures:
KX X
↓↓ ↓
1 2 3
YYYY
↓ ↓ ↓ ↓
4 5 6 7
1st Letter, "K" means capacitor
2nd Letter tells the type of dielectric (special for metallized version)
3rd Letter tells the purpose of use
4th, 5th, 6th, 7th Figure describe construction and design of capacitor and leads
Survey of letter used for single kinds of dielectric:
F - polyester film
E - metallized polyester film
L - polypropylene film
N - metallized polypropylene film
Film capacitors – Dielectric material
Polyester
Polypropylene
Dielectric
constant
εr= 3,3
εr= 2,2
Dielectric
loss
tanδ ≤ 60 ·10-4
at 1kHz
tanδ ≤ 5 ·10-4
at 1kHz
Temper. coefic.
of capacitance
TC ≈ +500 ·10-6/°C
(-100 ≤ TC ≤ -300) ·10-6/°C
Max. working
temperature
+125°C
+100°C
Dielectric
strength
295 kV/mm
300-380 kV/mm
Water
absorption
≤ 0,8 %
≤ 0,05 %
Film capacitors – Application
Radio interference suppression capacitors
Capacitors for use in electronics
Suppressor capacitor
L1
Cy
Cx
Power line
Equipment
L2
Cy
Every electronic / electronic / electrical equipment produce Radio
Frequency Interference (RFI).
RFI emission coming from inside or outside the system can be the
cause of equipment malfunctioning (Electro Magnetic
Susceptibility -EMS EMS).
National and International standards regulates the maximum
permissible noise level.
All suppressor capacitors have to be according with IEC 60384-14
Film capacitors – Application
Class X capacitors are suitable for applications where is no danger of electrical shock is case of
breakdown.
Class Y capacitors are suitable for applications where the breakdown of the capacitor can lead
to a dangerous electric shock
Class Y capacitors
Class X capacitors
Subclass
Impulse peak
operat. voltage
Application
Subclass
Impulse peak
operat. voltage
Rated voltage
X1
> 2.5 kV ≤ 4 kV
High peak
voltages
X2
≤ 2.5 kV
General
requirements
≤ 1.2 kV
General
requirements
8.0 kV
5.0 kV
none
2.5 kV
≤ 500 V
≤ 300V
X3
Y1
Y2
Y3
Y4
KNB capacitors (class X and Y) comply to standards
≥ 150V ≤250
< 150V
Standards for X2 capacitors:
IEC 60384-14
VDE-EN 132400
UL 1283
UL 1414
CSA C.22 No.1
CSA-E 384-14-95
CQC, GB/T14472
According to standards:
According to standards:
According to standards:
Remark for application (from our catalogue):
* taken from our catalogue (page 7)
Capacitance decreasing with the AC voltage corrosion phenomenon
The AC voltage corrosion of the metallized electrodes is one of the
predominant mechanisms of capacitance loss in a metallized
capacitor. The chemistry of the aluminium and zinc electrodes in
metallized capacitors is somewhat complicated by the variability in
the parity and structure of the vapor deposited layers, and by the
large surface to volume ratio that exist in a metallized electrode.
The electrode voltage corrosion is the result of an electrochemical
process taking place at the metallized electrode-polymer interface
and is manifested as transparent sites.
Capacitance decreasing with the AC voltage corrosion phenomenon
The AC voltage corrosion intensity depends of:
- Applied AC voltage level
- Frequency of AC voltage
- Ambient temperature
- Ambient air relative humidity
The AC voltage corrosion phenomenon degradates and reduces the metallized electrodes
active surface progressively and in linear-proportion with the time at the same conditions.
The capacitance decreasing is in the same proportion as is reducing the electrode active
surface.
Note: Voltage corrosion phenomenon is not present at DC voltage loading.
Example of electrode degradation
caused by corrosion phenomenon
KNB1560 0,68µF +10% -0% 275VAC. Capacitance loss cca. 75% after a time in service.
More reliable capacitors
− Suppressor film capacitor
− Application in series with the main
Possible solutions for long-term
capacitors stability:
1.
Electrode resistance to the AC voltage corrosion
Standard single connected winding construction made with improved metallized
electrode metal composition where the AC voltage corrosion phenomenon is not
present (Iskra CD version)
Advantages:
- long-term capacitance
stability
- no capacitors dimensions
change
- cost-effective construction
Possible solutions for long-term
capacitors stability:
2.
Double series connected winding construction
(made with film metallization design)
Each of single winding in capacitor is loaded with half of to the capacitor applied
voltage. The AC corrosion phenomenon is much reduced because of lower
electrostatic field strength between electrodes. Additional AC voltage corrosion
reduction is achieved with film dielectric type, selection of metallized electrode
metal and winding semi-impregnation.
Advantages:
- very high long-term capacitance
stability
Disadvantages:
- big dimension compare to single
connected winding construction
- high cost construction
Possible solutions for long-term
capacitors stability:
3.
Additional metallizied film improvements (included in new metallization
equipment for better AC voltage corrosion resistance):
- plasma treatment on the metallizing side of the film;
- oil overcoats after metallizing process;
- polymer coating (as example: acrylate layer);
- new corrosion stable electrodes
Tests according to standards:
Endurance test according to IEC 60384-14 for class X2:
Test conditions:
Impulse voltage test:
2,5kV, 1,2/50µs, 3x to 24x cycles
Temperature:
110°C ±3°C (upper category temperature)
Relative air humidity:
no relative air humidity
Voltage load:
1,25 Un + 1000VAC 50Hz for 0,1s/ 1x every hour
Test duration:
1000h (42days)
Change of capacitance ∆C/C must not exceed 10%
Endurance test according to UL1414 for class X2:
Test conditions:
Temperature:
85°C ±3°C
Relative air humidity:
no relative air humidity
Voltage load:
440VAC 60Hz + 880VAC for 0,1s/ 1x every hour
Test duration:
1000h (42days)
Change of capacitance ∆C/C is not specify
Other demands:
The 1-A fuse shall not rupture; after this test follows discharge test for expulsion
conductive parts of capacitor and dielectric voltage withstand and also discharge
test cheesecloth shall not glow or flame.
Tests according to standards:
Endurance test according to UL1283:
Test conditions:
Temperature:
100°C ±3°C
Relative air humidity:
no relative air humidity
Voltage load:
1,5 Un, 60Hz (for Un 275V = 412,5VAC 60Hz)
Test duration:
1000h (42days)
Change of capacitance ∆C/C is not specify
Other demands:
without voltage breakdown and without case damage
Dielectric Voltage-Withstand Test according to UL1414:
Test conditions:
Temperature:
lab.
Relative air humidity:
lab.
Voltage load:
1500VAC 60Hz
Test duration:
1min
Requirement:
without unacceptable parameters
Internal tests:
Test Iskra Kondenzatorji (eksikator):
Short accelerated test:
Temperature:
100°C
Relative air humanity:
100%
Voltage load:
385VAC, 50Hz
Test duration:
4days (= 96h)
Change of capacitance ∆C/C must not exceed 5%
Endurance test by Iskra Kondenzatorji:
Test conditions:
Temperature:
room temperature (20°C to 30°C)
Relative air humanity: 30% to 70%
Voltage load:
230VAC 50Hz
Test duration:
10000h
Change of capacitance ∆C/C must not exceed 2%
Internal tests (specify by costumers):
Test customer 1:
Test in chamber:
Temperature:
Relative air humanity:
Voltage load:
Test duration:
90°C
90%
380VAC 50Hz
4days (= 96h)
Test customer 2:
Test in chamber:
Temperature:
Relative air humanity:
Voltage load:
Test duration:
85°C
85%
290VAC 50Hz
21days (= 504h)
Change of capacitance ∆C/C must not exceed max. 10%, average 5%
Change of capacitance ∆C/C must not exceed max. 10%, average 5%
Internal tests (specify by costumers):
Test customer 3, Test condition 1:
Test in chamber:
Temperature:
40°C ±2°C
Relative air humanity:
93% ±2%
Voltage load:
300VAC 50Hz (Un)
Test duration:
56days (= 1344h)
Change of capacitance ∆C/C must not exceed 5%
Test customer 4, Test condition 1:
Test in chamber:
Temperature:
60°C ±2°C
Relative air humanity: :
93% ±2%
Voltage load:
230VAC 50Hz
Test duration:
7days (= 168h)
Change of capacitance ∆C/C must not exceed 5%
Internal tests (specify by costumers):
Test customer 5, Test condition 1:
Test in chamber:
Temperature:
60°C ±2°C
Voltage load:
275VAC 50Hz
Test duration:
2000h
Change of capacitance ∆C/C must not exceed 5%
Test Diehl Ako (85°C, 85% rH, 240V, 200h - Epcos test)
Film capacitors – Application
Where to use suppressor capacitors?
The KNB (X2
X2)
X2 metallized film capacitor is designed to filter spikes in parallel with the main at low frequency
(50/60 Hz).
The suppressor capacitor is supposed to withstand high peak voltage values through all its life and
then it must have high performances of self-healing.
In International Standards do not care about suppressor capacitance change in severe ambient
conditions.
For all the above reasons, KNB (X2) is recommended for circuit position in parallel with the
main (except KNB CD which can be used in series with the main too).
50-60 Hz
C
Equipment
Film capacitors – Application
Capacitors for use in electronics
C
Are designed to work in series with the main
Type: KFU, KEU, KLI, KNU, KNI, KNB CD
50-60 Hz
More reliable capacitors
KNB1530 CD
KNB1560 CD
KNU1910 CD,
mark on stamp
CD… custom design
Application
- serial and parallel connection in the circuits
- higher air-conditioning requirements (T and RH)
Equipment
Test Results Overview - Accelerated Humidity Test with
AC Voltage load (100°C, 100%RH, 96h at 485V 50Hz)
Results after test
Producer
Rated value - pitch
Material
average dC/C (%)
(range - %)
COMPETITOR1
0,068uF 275V AC R15
MPP 7x14
-41
(-33 to -53)
COMPETITOR1
0,12uF 275V AC R15
MPP 6x14
-25
(-23 to -28)
COMPETITOR1
0,56uF 275V AC R15
MPP 6x14
-8
(-6 to -10)
COMPETITOR1
0,47uF 275V AC R22,5
MPP 6x21,5
-17
(-14 to -22 )
COMPETITOR2
0,33uF 275V AC R15
MPP 7x14
-10,5
(-10 to -11)
COMPETITOR2
0,33uF 275V AC R22,5
MPP 7x21
-15
(-13 to -20)
COMPETITOR3
0,068uF 275V AC R15
MPP 7x13,5
-11
(-7 to -18)
COMPETITOR3
0,56uF 300V AC R27,5
MPP 8x26
-33
(-25 to -44,5)
COMPETITOR3
0,56uF 300V AC R27,5
MPP 8x26
-19
(-13 to -27)
COMPETITOR3
0,1uF 275V AC R15
MPP 8x13,5
-11
(-7 to -16)
COMPETITOR3
0,33uF 275V AC R22,5
MPP 8x21
-46
(-33 to -64)
COMPETITOR4
0,068uF 275V AC R15
MPP 8x14
-100
-100
COMPETITOR4
0,1uF 275V AC R15
MPP 8x14
-100
-100
COMPETITOR4
0,56uF 275V AC R27,5
MPP 8x26
-100
-100
COMPETITOR5
0,1uF 275V AC R15
MPP 8x14
-52
(-50 to -53)
COMPETITOR6
0,56uF 300V AC R27,5
MPP 8x26
-14
(-9 to -19)
COMPETITOR7
0,1uF 275V AC R15
MPP 7x14
-46
(-30 to -63)
COMPETITOR8
0,1uF 275V AC R15
MPP 8x14
-26
(-17 to -31 )
COMPETITOR8
0,33uF 275V AC R22,5
MPP 8x21
-21
(-17 to -27)
COMPETITOR9
0,1uF 275V AC R15
MPP 8x14
-90
(-49 to -100)
Test Results Overview - Accelerated Humidity Test with
AC Voltage load (100°C, 100%RH, 96h at 485V 50Hz)
Producer
Rated value - pitch
Material
ISKRA - KNB1560
0,1uF 275V AC R15
ISKRA - KNB1560
Results after test
average dC/C (%)
(range - %)
MPP 7x14
-24
(-19 to -32)
0,47uF 275V AC R22,5
MPP 7x21,5
-15
(-13 to -21)
ISKRA - KNB1560
1uF 275V AC R22,5
MPP 7x21,5
-13
(-8 to -19)
ISKRA - KNB1560 CD
0,1uF 275V AC R15
MPP 7x14
-1,5
(-1 to -3)
ISKRA - KNB1560 CD
0,47uF 275V AC R15
MPP 7x14
-1
(-0,5 to -1,4)
ISKRA - KNB1560 CD
0,47uF 275V AC R22,5
MPP 7x21,5
-0,85
(-0,6 to -1,1)
ISKRA - KNB1560 CD
1uF 275V AC R27,5
MPP 7x26,5
-0,38
(-0,14 to -0,57)
ISKRA - KNB1530
0,47uF 300V AC R22,5
MPP 8x21,5
-10
(-7,5 to -15)
ISKRA - KNB1530 CD
0,068uF 300V AC R15
MPP 8x14
-0,7
(-0,4 to -1,7)
ISKRA - KNB1530 CD
0,47uF 300V AC R22,5
MPP 8x21,5
-0,3
(-0,2 to -0,6)
ISKRA - KNB1530 CD
0,56uF 300V AC R27,5
MPP 8x26,5
-0,14
(-0,1 to -0,3)
Qulity inspection plan
Qulity inspection plan