HH
8 Temperature Limiter
• • Indication and switching function in case the fuse operates Protection of the fuse enclosure of SF6 switchgear against inadmissible temperature rise. All SIBA 80N striker pin systems are fitted with an integrated temperature limiter. Consequently each SIBA 80N striker pin has two functions:
SF6-insulated switchgear requires additional protection features against inadmissible temperatures of certain switchgear parts. The integrated temperature limiter avoids unacceptably high temperatures - no matter how they are generated in gas- insulated switchgear or narrow switchgear enclosures. By means of a melting activator, temperature inside the fuse enclosure is limited to below 100ºC. This design especially considers continuity of current to end user for as long as possible. The system reacts in such a way that short time overloads do not cause the fuse to interrupt the circuit unnecessarily. Only when values inadmissible are exceeded, the fuse will open the switch via the striker pin.
Higher temperatures on plastic fuse enclosures in SF6-insulated switchgear can be caused by:
Selection of a fuse rating too low for proper transformer protection Fuses loaded with fault currents below the minimum breaking current Deterioration of fuses caused by transient fault currents (e.g. lightning strike)
• • • • •
Transformer fault currents (e.g. winding short-circuit) Additional temperature rise because of poor clip fitting.
NEW - All fuses with the 50N striker now have incorporated the thermal limiter.
Fuses with an integrated temperature limiter are compatible with standard fuses. All coordination schedules can be used. Additional information on our temperature limiter and its design is available on our website:
portal:
www.siballc.net
www.siballc.net
portal: www.siballc.net e-mail: info@sibafuse.com
portal: www.siballc.net e-mail: info@sibafuse.com
14
Made with FlippingBook - Online magazine maker