CHINT NWC1 Series Installation instructions

Standard:IEC 60831-1-2014
IEC 60831-2-2014
NO:2021.01
NWC1 Series
Self-healing Low Voltage
Shunt Capacitors

Safety Warning
1 Only professional technicians are allowed for installation and maintenance.
2 Installation in any damp, condensed-phase environment with inflammable and explosive gas is
forbidden.
3 When the product is being installed or maintained, the power must be switched off.
4 You are prohibited from touching the conductive part when the product is operating.

Type Key and Definitions
Conditions for Normal Use, Installation and
Transportation, and Storage
Key Technical Parameters and Performance
Installation, Commissioning and Operation
Main Features, Outline and Installation Dimensions
Analysis and Troubleshooting of Faults
Maintenance and Storage
Product Selection and Ordering Information
11 Environmental Protection
01
01
01
02
04
04
06
06
07
08
08
Use Purpose and Application Range
Warranty Period, Environmental
Protection and Law & Regulations

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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
NLL≤10%NLL≤20%20%≤NLL≤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

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NWC1 Series Self-healing Low Voltage Shunt Capacitors
and heat dissipation of the capacitors under high temperature environment and keep the capacitors away
from heat source.
3.4 Transportation conditions: The capacitors should be transported within original package (packed
in foam box). The product should be handled carefully during transportation, to prevent the capacitor
body from deformation due to collision. The product should be placed on upper level when loaded
onto the truck. The capacitor assembly must be placed vertically during transportation, with an
inclination less than 30 degrees.
4 Key Technical Parameters and Performance
4.1 See Table 2 for key technical parameters
Table 2 Key technical parameters
Rate voltage (kV)0.4～0.69 See Table 3
Rate capacity (kvar)5~100 See Table 3
Rate frequency (Hz)50 or 60 Default 50
Capacitance deviation (%) -5～+8 Short circuit discharge
before test
Dissipation factor ≤ 30kvar product: tanδ≤0.0012
＞30kvar product: tanδ≤0.0015
Withstand voltage (kV)Inter-pole: power frequency 2.15UN, 2s
Pole-to-case: 2.0 UN+2 kV or 3 kV (take higher), 5s
Maximum allowable
overvoltage 1.1UN, no more than 8h of continuous operation within 24h
Maximum allowable
overcurrent 1.3IN, no more than 2h of continuous operation within 24h Short time≤2.0IN
Self-discharge characteristics
Residual voltage drops from √2UN to 75V(DC) or below
within 3min after power off.
Ambient temperature (℃) -25～+50 (-25/C)Customizable- 40～+50
Relative temperature ≤50% at 40℃, ≤90% at 20℃
Altitude (m)≤2000
Tightening torque (N?m)M6 screw ≤7, M8 screw ≤10
Safety protection Self-healing + overpressure protection+ discharge device Short circuit discharge
before test
Installation method Vertical
Note: Other voltages are customizable, the maximum capacity is 100kvar.
4.2 See Table 3 for specifications and outline dimensions of main models
Table 3 Specifications and outline dimensions of main models
Qc
√
3UN
Qc
UN
Rated current IN(A)
3-three
phase
1-single
phase
Rated voltage
UN(kV)
Optimal capacity
Qc(kvar)
Outline and installation dimensions
Capacity
range
Height
H
Figure
number
0.4, 0.415,
0.45, 0.525,
0.69
5, 7.5, 8, 10, 15,
16, 18, 20, 25,
30, 40, 50, 60,
80, 100
1~10 160 Figure 1
12~16 220 Figure 1
18~20 260 Figure 1
22~30 230 Figure 2
32~40 270 Figure 2
45~60 300 Figure 3
80~100 300 Figure 4
Note: See the outline and installation dimensions in this manual for the figure number of outline and installation
dimension drawings.

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NWC1 Series Self-healing Low Voltage Shunt Capacitors
4.3 The capacitors are placed in the capacitor compensation cabinet which should provide the
following protection measures. See Table 4 for details.
Table 4 Capacitor protection measures in cabinet
Protective
characteristics Name and function of support devices Typical models
Transient overvoltage
protection
Zinc-oxide surge arrestor or surge protector FYS-0.28 or NU6-2
Transient overcurrent
protection
Capacitor dedicated contactor, current limiting reactor, or smart
compound switch with zero-cross detection.
CJ19, XD1 or ZCK
Steady stage
overvoltage protection
Generally, compensation controller can provide overvoltage
protection.
NWK1-G, NWKL1
Steady stage
overcurrent protection
Thermal relay or capacitor switch with overcurrent protection
function.
JR36 or ZCK
Short circuit protection Choose fast acting fuse for short circuit protection. For capacitors
with capacity＜30kvar, user can use miniature circuit breaker for
short circuit protection. For capacitors with capacity ≥30kvar,
miniature circuit breaker is not recommended.
RT36 or NT00
NWC1 series square case products consist of fully independent units with automatic protection
functions. The units use cylindrical stretched aluminum enclosure while the case is made of cold-roll steel
sheets. This structure provides double protection which eliminate the risks of explosion and leakage and
guarantees safety. See Figure 1-4 below for outline and installation dimensions.
5 Main Features, Outline and Installation Dimensions
67
H
H+34.5
194
25 25
224
206
41
Φ 6
×
10
Figure 1 (1-20) kvar outline and installation dimensions
3-M6
132
224
254
Φ 12 × 16
Figure 2 (22-40) kvar outline and installation dimensions
3-M8
H
H+41
194
28 28
132
350
380
Φ 12 × 20
320
300
80
375
80
Figure 3 (45-60) kvar outline and installation dimensions
3-M12
380
350
Φ 12 × 20
196
320
300
375
80 80
3-M2
Figure 4 (80-100) kvar outline and installation dimensions

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NWC1 Series Self-healing Low Voltage Shunt Capacitors
Note: Refer to Table 3 based on capacitor model, then look for the outline and installation dimensions in Figure 1,
Figure 2, Figure 3 and Figure 4.
Example: For model NWC1-0.45-20-3, user can refer to Table 3 and find that H=260mm, then check
Figure 1 for outline and installation dimensions. The outline dimension is 194mm×67mm×294.5mm, the
installation dimension is 206mm×41mm.
6 Installation, Commissioning and Operation
6.1 Installation and Fixing
NWC1 series products are equipped with mounting feet. Figure 1 shows waist-shaped long holes for
insert type installation, Figure 2~ Figure 4 show mounting holes that are bilateral symmetry. Use screws with
dimensions shown in the Figures and tighten them to install and fix the product.
6.2 Installation spacing
6.3 Wiring requirements
The capacitors should be connected by stranded soft conductors, with pressed dedicate copper
connecting lug. See Table 6 for the selection of conductor sectional area.
Figure 5 Capacitor installation drawing
Table 5 Installation spacing and safety distance
Capacity (kvar) Minimum installation spacing
S1(mm)
Safety distance at the top of capacitors
S2(mm)
1~20 30 ≥50
22~32 50 ≥50
35~100 80 ≥50
6.4 Preparation and inspection before use
6.4.1 Before using the capacitor, user should check if the model on the nameplate is consistent with that of
the product. User should also check if the included accessories are complete;
6.4.2 Capacitor testing: Use digital capacitance meter to test the capacitance value between any of the two
phases of the 3-phase capacitor, the result should be about half of the rated value;
6.4.2 Before using the capacitor, user should check if all the connections are secure and if the dust guard is
installed, make sure the capacitor is reliably grounded.
6.5 Monitoring and recording during operation
Table 6 Selection of conductor sectional area
Rated voltage (kV)Rated capacity (kvar)Conductor sectional area (mm2)
0.4, 0.45, 0.525 ≤10 4.0
0.4, 0.45, 0.525 12~20 6.0
0.4, 0.45, 0.525 24~32 10.0
0.4, 0.45, 0.525 35~60 16.0 or 25.0

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NWC1 Series Self-healing Low Voltage Shunt Capacitors
6.5.1 User should check the operating status of the capacitors on a regular basis, check if the 3-phase current
is balanced by using the amperemeter in the cabinet.
6.5.2 If the 3-phase current is not balanced, use clamp on amperemeter to test the current and voltage of
phase A, phase B and phase C of each group of capacitors.
6.5.3 If there is voltage but no current between phases, it means the overpressure protector is disconnected,
user should maintain the product in time or replace it if necessary.
6.5.4 Check the surface temperature of capacitor case during operation, if the temperature of any individual
capacitor case exceeds 65℃, maintain the product or replace it if necessary; if the temperature of all the
capacitor cases is higher than 65℃, take effective ventilation and heat dissipation measures and check if any
harmonic source device (such as frequency converter, rectifier and inverter, and medium and high frequency
heating furnace) is used at user load end.
6.6 Operation procedure, method and precautions for shut down
6.6.1 If any deformation, oil leakage is found on the capacitor case or the reactive compensation controller
is not working normally, shut down the equipment for inspection and repair.
6.6.2 If the busbar in the cabinet is of bottom-in and top-out type, user must disconnect the bus before
replacing the capacitors or other electric components. However, user only needs to disconnect the isolation
switch in the cabinet when changing the secondary wiring or testing the capacitors.
6.6.3 Before testing and touching the capacitors, user must conduct short circuit discharge between each
two terminals of the 3-phase capacitor.
7 Maintenance and Storage
7.1 Daily maintenance and calibration
Check if the operating current of the capacitor is normal by using the amperemeter and compensation
controller in the cabinet. Check if there is any deformation, oil leakage and overheating. Abnormalities such
as overcurrent and overtemperature caused by harmonic will reduce the service life of the capacitor and can
cause damage to other components and conductors in the cabinet due to overload.
7.2 Maintenance during operation
Tighten the terminal screws of the capacitor on a regular basis (once half a year) to prevent poor
contact. Remove dust and greasy dirt also.
User should pay close attention to the cabinet and replace any damaged capacitor in time if any under
-compensation of power factor occurs due to significant capacitance drop (50% current decrease), otherwise
it may lead to penalty. If all the capacitors are operating and in good condition but the power factor still
cannot meet requirement, user must add capacity in time to ensure the automatic cycle operation of the
capacitors.
7.3 Service cycle
User should determine the service cycle based on the application conditions, the recommended service
cycle for cabinet is once half a year.
7.4 Maintenance for long-term idle
If the capacitor has been idled for one year or longer, please check if its capacitance value is within the
allowable deviation range (-5%~+8%); conduct pole-to-case voltage withstand test again (apply AC 3kV for
5 seconds); or use megameter to test if the insulation resistance between the three phase terminals and the
case is larger than 100MΩ before using the product.
7.5 Storage conditions, storage period and precautions
The smart capacitor should be stored in a dry and well ventilated room and protected from rain, moist,
chemicals and dust. The maximum storage period of the product is 36 months. Do not put the smart
capacitor or its package directly on the floor.
8 Analysis and Troubleshooting of Faults

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NWC1 Series Self-healing Low Voltage Shunt Capacitors
Table 7 Analysis and Troubleshooting of Faults
No.Faults Cause analysis Troubleshooting method
1
The measured current of a newly
connected capacitor is much
smaller than the rated current on its
nameplate (same for multiple
capacitors).
If a capacitor with higher rated
voltage is connected to 380V grid,
the actual output current will be
much smaller, which is normal.
There is nothing wrong with the
capacitor, it is just derated.
User should determine the status
of a capacitor based on its
measured capacitance value (μF).
The actual operating current IC=
Uc/UN ×IN
2
The current of the capacitor is
closed to rated current when it is
first put into operation, but the
current drops after a period of time.
The current drops as the
capacitance value of the
capacitance decreases.
There are several reasons for
capacitance decrease such as
improper use, large harmonic or
quality defect.
Find out the reason and solve the
problem. User must replace the
capacitor if the capacitance value
drops below 50%.
3
The terminal screws of the capacitor
generate heat or even turn into
black during operation.
The wire nuts are loose or not
tightened properly during
installation.
If the nuts are tightened properly,
the reason might be long-term
overcurrent due to harmonic
current amplification in the grid.
Tighten the nuts, replace nuts, flat
gaskets, elastic washer if necessary.
4
The fuse in branch circuit blows
frequently (or miniature circuit
breaker trips frequently); the CJ19
contactor fuses; the current-limiting
resistance burns frequently; the
surface of XD1 current-limiting
reactor case cracks, etc.
These symptoms are typical when
the grid harmonic is too big or
there is intermittent resonance in
the grid.
Conduct grid harmonic test or
check if there are harmonic
sources such as frequent
converter, rectifier, intermediate
frequency furnace or electric-arc
furnace installed at load end. See
3.3.2 for harmonic suppression
measures.
5
Sometimes there is buzzing sound
in the cabinet during operation.
There is harmonic current passing
through the capacitor.
User must take harmonic
suppression measures if the
harmonic current is too big
(same as 4)
6
There is significant current increase
when adding a capacitor into a
group.
Either abnormal power frequency
resonance (underloading), or
harmonic current amplification or
there is resonance.
Same as 4
7
Slight deformation occurs to the
capacitor case after the capacitor
has been used for a period of time,
and no current can be detected.
Long-term overtemperature or
overcurrent operation of the
capacitor which cause self-healing
breakdown of internal components
that generates gases and increases
internal pressure. When the
overpressure protector breaks,
slight deformation can occur to
the capacitor case.
Use heat dissipation measures to
lower the ambient operating
temperature of the capacitor.
Select products with higher rated
voltage. Harmonic suppression
measures are the same as
described in 4.
9 Warranty Period, Environmental Protection and Law & Regulations
9.1 Warranty period
The warranty period of the product is 30 months from production (delivery) date if the product is kept
under normal storage conditions and the package or the product itself is in good condition. If the warranty
period has expired, please inspect the product and make sure it meets all the requirements before installing
and using the product. The following circumstances are not within the scope of warranty (excluding repair
or replacement):

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NWC1 Series Self-healing Low Voltage Shunt Capacitors
1) Damage due to improper use, storage or maintenance by user
2) Damage due to dismantle or repair by unauthorized agency or personnel or by user itself
3) The warranty period or service life of the product has expired.
4) Damage due to force majeure
5) Other man-made damages
9.2 Environmental Protection
In order to protect the environment, the product or product parts should be disposed of according to
the industrial waste treatment process, or be sent to the recycling station for assortment, dismantling and
recycling according to local regulations.
In order to protect the environment, the product or product parts should be disposed of according to
the industrial waste treatment process, or be sent to the recycling station for assortment, dismantling and
recycling according to local regulations.
10.1 User should provide product parameters such as rated voltage, rated capacitance, number of
phases, etc;
10.2 User should provide as many application conditions as possible, such as altitude, grid harmonic
environment and application industry.
10 Product Selection and Ordering Information
11 Environmental Protection

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NWC1 Series Self-healing Low Voltage Shunt Capacitors
DR/J03
NWC1 Series
Self-healing Low Voltage
Shunt Capacitors
IEC 60831-1-2014
IEC 60831-2-2014

NWC1 Series
Self-healing Low Voltage
Shunt Capacitors
User Instructions