08-16-2017, 08:57 PM
Outdoor live tank SF6 circuit breaker
[attachment=18113]
ABB a global leader
ABB (abb.com) is a global leader in power and
automation technologies that enable utility and
industry customers to improve performance while
lowering environmental impact. The ABB Group of
companies operates in around 100 countries.
ABB s Power Technologies division offers electric,
gas and water utilities as well as industrial and
commercial customers a wide range of products,
system and service solutions for power
transmission and distribution, integrated solutions
for power generation plants, utility automation and
bulk power transmission.
Breaker construction
The SF6 outdoor high-voltage breaker type ELF SP
has two interrupting chambers per pole arranged in
T formation and can handle breaking currents up
to 80 kA. The interrupting chambers are based on
the puffer piston principle and equipped with double
contacts. High dielectric strength is ensured by the
wide space between the open contacts.
Each set of interrupting chambers is driven via an
actuating rod by a pneumatic operating mechanism,
which is kept at earth potential for safety.
pneumatic operating mechanism
Each breaker pole is provided with its own
pneumatic operating mechanism. The operating
mechanism is based on the differential piston
principle with the sequence of movements being
pneumatically damped. Energy storage is
accomplished with the aid of an air receiver. A
compact design has been achieved by means of the
fully integrated configuration.
Maintenance
On account of the long service life of the switching
contacts and the use of synthetic bearings,
maintenance has been minimised. Inspection of
contacts is necessary only after 5000 switching
cycles at rated current. The leakage rate of SF6 gas
is restricted to within 1% per annum and is achieved
by employing a redundant SF6 gas sealing system.
This ensures a long service life without
replenishment of SF6 gas.