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Introduction
NCL
snubber capacitors are designed to meet the requirements of the traction
industry and for static drive applications. They are built to extremely high
standards, offering enhanced properties over other similar looking designs.
Wound with a combination of metallised polypropylene film and extended
aluminium foil electrodes which, in conjunction with a stable, biodegradable
liquid impregnant ensures extremely long life and reliable self-healing
capabilities. The loss angle (tandf) is extremely
low (<0.0003 at 1kHz) and the aluminium foil electrodes provide excellent
thermal characteristics.
Application
NCL
snubber capacitors are designed for the severe duty of gate turn-off
thyristors (GTOs). They are also for tuning applications in the medium
frequency range. |
Technology
The
advanced polypropylene dielectric system of these capacitors has been
specially developed for high peak current and surge voltage applications.
Encapsulated in fire-resistant epoxy resin, the extremely strong robust
mechanical design is suitable for the rigours of traction duty, especially
vibration conditions and high ambient temperatures. M8x8 mm axial
connections are provided, which are securely bonded to the foil electrodes.
The
range below should not be considered as definitive. For example:- NCL is
able to manufacture special high temperature versions which are capable of
operation up to 120°C. For any models not shown within these ranges, please
contact us for further details. |
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Characteristics
The
following parameters are applicable to the range of capacitors which appear
on the following pages. As mentioned above, should a particular combination
of capacitance value or voltage not be available or should there be a
dimensional constraint, please contact us for a design suited to your
particular needs.
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Capacitance value: |
0.25µF to 8µF |
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Tolerance: |
± 5%
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Voltage rating (Udc): |
900V
to 3700V |
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Peak
repetitive voltage (UN): |
1400V to 5500V |
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Peak
non-repetitive voltage (Us): |
1800V to 7200V |
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Maximum surge current: |
700A
to 8200A |
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Loss
angle (tandf): |
<0.0003 at 1 kHz |
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Insulation resistance: |
>10,000 sec |
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Current rating: |
Up
to 120 A rms, depending on capacitance, voltage rating and thermal
constraints |
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Operating
temperature (qamb): |
-40
to +70°C |
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Storage temperature: |
-40
to +85°C |
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Connections/tightening torque: |
M6 x
6 mm internal thread brass connection - 3 Nm
M8 x 8 mm internal thread brass connection - 6 Nm |
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International standard: |
In
accordance with IEC 61071 & IEC 61881 |
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