• ALPO-type busducts are an integrated transmission line system designed mainly for:  
  • deriving power from medium and high power generators, 
  • making connections of devices in systems of high short-circuit power,
  • making group connections of single-phase transformers, 
  • making connections of the power supply system of own needs, 
  • distribution of power in plants.

ALPO type busducts are reliable power installations in the voltage range from 7.2 to 36 kV and rated current from 1.25 to 18 kA, with air insulation and natural cooling. They are adapted for both indoor and overhead operation. They can be operated in dusty and humid conditions.   
ALPO type busducts can be made in two varieties:

Without overpressure, which means that the air inside the busduct is at atmospheric pressure. 
With an overpressure system, where a small overpressure (1 kPa) of dry air is maintained inside the busbar with the help of appropriate installation and apparatus. 

The dry air system is permanently connected to the external shield, and with the help of a reducing station, the pressure inside the busbar is automatically controlled and regulated. The dry air overpressure, maintained continuously inside, completely eliminates the phenomenon of moisture condensation on insulating elements and prevents the penetration of dust particles. 
Support insulators
Standard designs of busducts use support insulators made of epoxy resin. The insulators are used as fasteners for the current tracks in the shield. 

Pass insulators
Pass insulators are used in basic designs as a barrier separating the busway zone with dry air overpressure, from the zone with atmospheric pressure, or in installations without overpressure as a barrier to prevent moist air from being drawn into the busway when the connection covers to transformers or generators are opened during inspections and maintenance.

Compensation elements  
Busways are equipped with compensation elements for the current path and shield which compensate for axial displacements caused by the phenomenon of thermal expansion and eliminate the transmission of vibrations from power equipment. 
The current path compensator is made of appropriately selected single aluminum flexible corrugated joints welded into the current bus string. 
The shield compensator, made of extruded aluminum sheet, compensates for elongation and ensures the tightness and continuity of the section.  
Shield compensator of busbar connections with connection covers to transformer, generator, etc. made of silicone rubber which compensates for shield elongation and transmission of vibrations to busducts emitted by cooperating equipment.

Supporting elements 
Bus ducts are standardly equipped with aluminum support elements by means of which they are attached to supporting structures, beams or ceilings. 

Electrical apparatus
The design of busducts allows the installation in special covers or directly in the screen of electrical apparatus such as switches, current and voltage transformers, lightning arresters and others.   

Connections to devices 
Connections to devices such as transformer, generator, switchgear, etc. are made of aluminum shields. The terminals of the equipment are connected with flexible connectors, copper or aluminum with silver-plated or tin-plated contact surfaces.  The shields have suitable hatches or are designed to provide easy access to or easy removal of demountable connections. 

Protection against direct contact
Protection against direct contact is provided by aluminum busbar screens, with IP65 protection level, and connection covers which are resistant to deformation and stresses occurring during normal operation. 

Protection against indirect contact 
In ALPO type busducts, the shield is connected to ground at one or more points. All types of doors are provided with special grounding terminals and are short-circuited to the shield using copper wires.  The protective terminals of electrical apparatuses are connected by shorting wires to the shield, which is treated as the main protective conductor. 

Design and calculations.
Design and calculations are carried out by experienced designers, combining specialized engineering knowledge and experience with specialized software.  As a result, after the consultation process, we provide the most optimal design solutions that meet the required technical parameters and operating conditions, and at the same time are the most advantageous from the point of view of the investment budget. 

Type tests
Busducts are subjected to type tests, carried out in accordance with 
accordance with international standards (ANSI, IEC, EN) by a prestigious, accredited, independent certification body.  Type testing, which is a special requirement of the project, can be carried out at the expense of the customer, after agreeing on all the terms of implementation.



Alstema has manufactured thousands of meters of medium-voltage busducts for dozens of major Power Plants, Thermal Power Plants, Chemical Plants and Refineries in Europe, Asia and Africa. The company's specialty is single-phase busduct (IPB) and three-phase busduct (SPB / NSPB) in round and rectangular designs. In addition, the power distribution cycle includes the company's other projects: power lead cabinets, generator zero cabinets, equipment connections, coolers and other equipment supplied to the world's leading power facility Contractors.


  • comprehensive installation of our own and other manufacturers' busducts, 
  • installation of Generator Switches, 
  • periodic inspections with the possibility of extending the warranty period, 
  • replacement of components in existing systems, 
  • modernization of old systems to new parameters, 
  • modification of connections after replacement of transformers, switchgear,
  • Dry air overpressure systems in existing buses,
  • emergency service.


  • comprehensive installation of busducts of our own production,
  • assembly of busducts of other manufacturers,
  • installation of Generator Switches in existing power lead-out systems,
  • adaptation of busbar connections after the replacement of transformers and switchgears,
  • control and measurement apparatus and automation,
  • electrical and power facilities,
  • auxiliary equipment in power plants,
  • industrial pipelines,
  • steel structures and industrial installations,


The Project Scope includes:
1. technical support to project participants, including in-house measurements 
at the target facility, clarifications, meetings, reviews, assumptions, guidelines 
and interprofessional agreements,

2. the Design Documentation developed to obtain solutions that meet the required technical parameters and operating conditions, and at the same time the most favorable for the investment budget, among other ...