ABB has launched a 420 kV version of its high voltage hybrid packaged switchgear offering.


The design enables the bushings to be rotated from a transport to a service position and vice-versa, a process that takes less than 30 seconds for each bushing.

The new product belongs to ABB’s PASS (‘plug and switch system’) family of HV switchgear and extends its capability from the existing 170 kV and 252 kV modules to the full 420 kV transmission level. The main characteristic of this family of switchgear offerings is that it integrates the functions of circuit breaker, disconnector and earthing switch as well as current and voltage instrument transformers in one product, which is pre-assembled and factory-tested to cut down installation and commissioning time. The resulting module is therefore equivalent to a complete switchgear bay. Its compactness can help reduce the footprint of the bay where it is installed by up to 50 % when compared with air-insulated switchgear of a comparable rating. Installation too is correspondingly fast – typically 24 hours for the lower voltage units.

M0S 420 version

The M0S 252 kV unit has been available for some time. It is equipped with a well-proven rotating combined disconnector and earthing switch and has a breaking current of 50 kA.

The new unit has a breaking current of 63 kA and can be erected and commissioned in three working days. The available configurations are single bus bar (SBB), double bus bar (DBB) or double circuit breaker.With the introduction of the 420 kV module the PASS product family now covers voltages from 72.5 kV to 420 kV with breaking current capability ranging from 31.5 to 63 kA. In addition to standard modules a special solution called the PASS M0 H offers a complete high voltage switchyard with an ‘H’ configuration as a single product.

Hybrid technology

The PASS family of switchgear modules employs a hybrid technology solution. On one side it uses the reliable air insulated connections between modules, while on the other it encloses the bay functions in a single phase gas insulated housing containing the circuit breakers, disconnector, earthing switches (fast or slow), voltage transformers and voltage sensors, current transformers, and bushings or cable enclosures.

ABB says that this configuration has several advantages besides those of compactness and fast erection/commissioning, namely a high degree of customisability, notwithstanding the short delivery time, due to the modular design and the implementation of ‘just in time’ and ‘assemble to order’ production models, a high level of reliability, due to the use of standardised and reduced number of components, and a life cycle cost significantly lower than traditional technologies.

Design of the PASS M0S

The interrupting chamber of the circuit breaker is operated by a single-phase spring mechanism loaded by a motor drive. The disconnecting switch and the earthing switch are part of a common rotating mechanism operated by a motor drive.
The bushings are made of a fibreglass tube provided with external silicon rubber sheds, whose auto-cleaning characteristic eliminates the necessity for periodical removal of conductive film.

The modules can be supplied with inductive current transformers, gas insulated inductive voltage transformers, compactcontrol and protection integrated systems and gas insulated surge arresters.


Necessary maintenance operations can be carried out during service and without the need of any outage. There is no need for regular cleaning of the switchgear contacts since all active parts of the equipment are gas insulated. This also reduces the time and cost of servicing the equipment in addition to enhancing its reliability and availability.

“ABB offers a wide range of hybrid high voltage switchgear solutions to suit varying customer needs and the new compact and highly reliable 420kV PASS complements our existing GIS based ELK hybrid technology" said Giandomenico Rivetti, head of ABB’s High Voltage business, a part of the company’s Power Products division. "The innovative design features of this new product enable ease of transportation and make it quick and easy to install."