ABB Unisec

Modular air-insulated switchgear for all applications in secondary power distribution up to 24 kV

UniSec is an indoor air-insulated switchgear for medium voltage secondary distribution up to 24 kV. It offers a broad portfolio of functional units and technical features and is suitable for a wide range of applications including industry, renewable energy plants, distribution and transformer substations, data centers, small generation systems, buildings and infrastructure, and smart grids.

UniSec also offers a sulfur hexafluoride (SF6) free variant called UniSec Air. The new switchgear includes the load break switch (LBS) and disconnector GSec Air. This new component has a shunt vacuum interrupter for breaking capacity as the insulation medium with a global warming potential (GWP) of zero. The switchgear also contains a vacuum circuit breaker and is fully compliant with IEC standards and the EU F-gas regulation (EU) 2024/573.

UniSec features a modular design and is tested according to the latest IEC 62271-200 standard and GB specifications. The switchgear, with corrosive and pollution-resistant materials, is certified for installation in the most severe conditions like marine, areas with high seismic hazards, and low temperature environments.

Removable and withdrawable SF6 and vacuum circuit breakers
Suitable and certified for installation in the most severe conditions like marine, areas with high seismic hazards, and low temperature environments

Interlocks

• Another important issue to bear in mind is how the medium voltage compartments can be accessed during normal operation, for maintenance work or any other reason. IEC 62271-200 defines three methods for controlling the way an accessible compartment is opened:

– The first involves the use of interlocks to ensure that all live parts inside the switchgear are dead and earthed before the compartment is opened

– The second is based on the user’s procedure and on a locking device to ensure safety. In this case, the compartment is equipped with padlocks, keys, locking magnets or some other equivalent device

– The third method does not provide for any integrated devices to ensure electrical safety prior to opening, but tools are required to open the compartments; even commonly used objects, like screwdrivers or pliers, are considered tool

Application	Acronym	190 mm	375 mm	500 mm	600 mm	750 mm
Feeder with load break switch	SDC, Load break switch		*	*		*
Coupler with load break switch	SDS, Load break switch		*	*		*
Feeder with double load break switch	SDD, Load break switch					*
Coupler with load break switch for measurement	SDM, Load Break Switch					*
Universal metering unit	UMP, Universal Metering Panel					*
Direct feeder with measurement and busbar earthing	DRC, Direct Riser		*	*
Riser with measurement	DRS, Direct Riser Sectionalizing		*	*
Measurement with fused load break switch	SFV, Switch Fused Voltage			*		*
Feeder with fused load break switch	SFC, Switch Fused Cables		*	*		*
Coupler with fused load break switch	SFS, Load break switch with fuses		*	*
Feeder with circuit-breaker and load break switch	SBC, Switch Breaker Cables					*
Feeder with circuit-breaker and air disconnector	SBC-AirD, Air disconnector Breaker Cable					*
Feeder with withdrawable circuit-breaker and load break switch	SBC-W, Switch Breaker Cables withdrawable	*	*	*		*
Coupler with circuit-breaker and load break switch	SBS, Switch Breaker Sectionalizing	*	*	*		*
Coupler with circuit-breaker and air disconnector	SBS-AirD, Air disconnector Breaker Sectionalizing	*	*	*		*
Coupler with withdrawable circuit-breaker and load break switch	SBS-W, Switch Breaker Sectionalizing withdrawable	*	*	*		*
Coupler with circuit-breaker and double load break switch for measurement	SBM, Switch Breaker Measurement	*	*	*		*
Coupler with withdrawable circuit-breaker and double load break switch for measurement	SBM-W, Switch Breaker Measurement withdrawable	*	*	*		*
Reversed feeder with circuit-breaker and load break switch	SBR, Switch Breaker reversed	*	*	*
Feeder with integrated circuit-breaker and disconnector	HBC, Hybrid Breaker Cables	*	*	*
Feeder with contactor and load break switch	SCC, Switch Contactor Cables					*
Coupler with integrated circuit-breaker and disconnector	HBS, Hybrid Breaker Sectionalizing			*
Left or right lateral cable riser	RLC/RRC, Riser Left/Right Cables	*
Feeder with withdrawable frontal circuit-breaker	WBC, Withdrawable Breaker Cables				*	*
Coupler with withdrawable frontal circuit-breaker	WBS, Withdrawable Breaker Sectionalizing				*	*
Direct feeder with measurement and busbar earthing	BME, Busbars Measurement Earthing				*