• GTO Snubbers
  • Thyristor Snubbers
  • IGCT Protection
  • DC Filters
  • IGBT Filters
  • IGBT - AC Harmonic Filters
  • Energy Discharge Capacitors
  • Norfolk Capacitors Limited
     
    Section
    Start
     
    Previous
    Page
    Next
    Page
     
    Home
    Page
     

    About Us
    A brief profile of NCL and a description of company objectives.
    Products
    Information about our catalogue products their general construction and application.
    Sales
    Contact information for our sales department UK and world wide.
    Enquiry Form Fill in the enquiry form and receive a competitive quotation for the capacitor you require.

    Image Gallery
    Full colour thumbnail picture collection of NCL's products which you can click on to enlarge.

    Site Not Right!
    Please contact our site administrator if any pages have errors quoting where and which site the error is on.

    Made in
    Great Britain
     
    Optimal settings
    1024x768 <
    16 bit colour >
    IE4 or NS4 >
    GTO Protection Capacitors ~ introduction

    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.

    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.

    Capacitance value: 0.25µF to 8µF
    Tolerance: ± 5%
    Voltage rating (Udc): 900V to 3700V
    Peak repetitive voltage (UN): 1400V to 5500V
    Peak non-repetitive voltage (Us): 1800V to 7200V
    Maximum surge current: 700A to 8200A
    Loss angle (tandf): <0.0003 at 1 kHz
    Insulation resistance: >10,000 sec
    Current rating: Up to 120 A rms, depending on capacitance, voltage rating and thermal constraints
    Operating temperature (qamb): -40 to +70°C
    Storage temperature: -40 to +85°C
    Connections/tightening torque: M6 x 6 mm internal thread brass connection - 3 Nm
    M8 x 8 mm internal thread brass connection - 6 Nm
    International standard: In accordance with IEC 61071 & IEC 61881