UniSec expands its portfolio with the new HBC unit

2013-07-11 - After completing the series, the UniSec switchgear now offers the new HBC functional unit, which features an extremely compact size and the use of the multifunction HySec apparatus, which integrates a circuit breaker and a switch-disconnector in the same device.
Dalmine - Italy, July 11, 2013. ABB, the group leader in energy and automation technology, presents the new UniSec HBC functional unit. Thanks to this new unit, UniSec is now the most complete platform for medium voltage switchgears - able to satisfy the requirements of all secondary distribution systems up to 24 kV.

The product of ABB research, UniSec HBC is a medium voltage air insulated panel with innovative features. It is particularly recommended for applications where a compact medium voltage panel is required. Thanks to the adoption of the multifunction HySec apparatus, the width of the HBC panel has been reduced to just 500 mm, while maintaining easy cable connections at a height of 600 mm from floor level.

HySec integrates the circuit-breakre and switch-disconnector functions.
HySec is a multifunction apparatus with integrated circuit breaker and switch-disconnector inside a single housing. The breaking mechanism of the circuit breaker and disconnector is located at the front and a series of interdependent interlocks ensures error-free operations.

The housing of the integrated HySec apparatus consists of an upper part made of epoxy resin which guarantees the insulation class and a lower part, made of stainless steel,
which provides the panel with metal segregation.

The vacuum system, which serves as circuit-breaker, is installed in the resin section and is operated by a dedicated operating mechanism. The disconnecter contacts are housed in the lower part, in an SF6 atmosphere, which offers the three classic positions: line/isolated/earthed.

The main features of the HySec multifunction apparatus are:
- HySec fully tested as a single component
- all mechanical interlocks are integrated
- excellent resistance to external environmental conditions thanks to the integration of the switch-disconnector components in one shell with SF6.

UniSec HBC unit.

The UniSec HBC consists of two compartments, busbars and cables. The cable compartment can be accessed while the busbars and adjacent panels are live. The "earthed" position of the HySec apparatus allows the cables to be earthed directly, and the presence of a mechanical interlock with the door of the cable compartment guarantees the utmost in safety.

These features allowed the UniSec HBC panel to be classified as LSC2A-PM under IEC 62271-200, thereby guaranteeing maximum safety for personnel, who can work inside the line compartment even when the main busbars are live.

Like other UniSec panels, the HBC unit is internal arc proof and respects all five criteria of the IEC regulations. In the case of an internal arc, the panel must fulfill the following requirements:
  1. The doors of the control panel must remain closed and the structure of the control panel must remain intact
  2. No part of the panel considered to be dangerous for personnel may be ejected
  3. No opening may be present on the external part of the panel accessible to personnel
  4. Indicators located on the outside of the panel vertically or horizontally must not ignite
  5. All earth connections of the panel must be guaranteed.
All the available solutions are A class (only authorized personnel) and can be accessed from different sides (F for front, L for lateral, R for rear).
Section view and single line diagram of HBC unit.
The UniSec HBC panel can be used both to protect and control both the incoming and outgoing feeders and can be coupled, in the same switchgear, with all other available units.

All this means extremely flexible usage, making it possible to perfectly satisfy all types of system needs. Thanks to the earthing switch, the UniSec HBC panel can also be used as an incoming feeder, in accordance with CEI 0-16 standards.

The HBC units make the UniSec switchgear perfect for all uses, especially for substations, utilities, industry, commercial and residential buildings, etc. as well as any other application where compact size is a fundamental requirement.

The new array of UniSec panels confirms ABB's leadership in the air insulated secondary distribution panel sector, making it a trusted and innovative partner for all the main utilities and industries, effectively contributing to the development of electrical grids.

UniSec HBC panel electrical characteristics
Rated voltage up to 24 kV
Test voltage (50-60 Hz for 1 min) up to 50 kV
Impulse withstand voltage up to 125 kV
Rated frequency 50-60 Hz
Rated main busbar current up to 1250 A
Rated HySec multifunctional apparatus current up to 630 A
Rated short-time withstand currentup to 16 kA 1 s
Peak current up to 40 kA
Internal arc withstand current (IAC)up to 16 kA 1 s

ABB (www.abb.com) is a 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 and employs about 145,000 people.