EHON non-segregated three-phase busducts (NSPB busducts)

Non-segregated three-phase circular busducts are a more economical and more reliable solution for current connections than three-phase rectangular busducts type and cables.

They are highly reliable and maintenance-free. These advantages are achieved by a special welding technology of the conductors and enclosure at the stage of the busduct assembly. This avoids bolted connections on the entire length of the busduct. This way a busduct may be made up to the IP65 degree of protection.

HOLDUCT provides three-phase busducts optimized for the needs of the customer in order to get the most savings through:

reduction of losses,
reduction of assembly time,
busduct trunking and support structure configuration.

Our support engineers are ready to help you even at the stage of the development of a power plant concept project.

Summary of the characteristics of round and rectangular busducts

Rectangular busduct

Round busduct

Bolted connections of current conductors and enclosure.

Problem:

The need for periodic inspection of bolted connections.
The need for additional maintenance hatches, which may cause compromised air and water-tightness – the degree of protection max. IP55.

Welded joints of current conductors and enclosure

Solution:

Maintenance-free busduct operation,
The degree of protection IP65.

Parallel arrangement of current conductors.

Problem:

Low resistance to short-circuit currents requires dense insulator structure.

Symmetrical localisation of current conductors in the housing every 120°.

Solution:

High resistance to short-circuit currents allows a greater span between the supporting insulators.

Degree of protection IP65

Problem:

Inability to use in harsh industrial environments because of the danger of humid and polluted air entering into the busduct.

Degree of protection IP65

Solution:

The possibility of using a dry-air overpressure system allows for reliable and safe operation of the busway in harsh industrial environments with high dust and moisture.

Short sections for transport (approx. 4m) due to lower mechanical strength.

Problem:

Longer installation time due to the greater number of connection points.
Smaller spacing between supporting structures (every 3-4m) and, consequently, an increased number of them.

Transport sections up to 12m long.

Solution:

Approximately 50% fewer connection points in the system results in shorter installation time.
Increased spacing between the supporting structures allows the use of a reduced number of supports.

Design:

A three-phase circular busduct is a shielded, self-supporting, naturally cooled air-insulated busduct.

Three phase conductors are arranged symmetrically in a common housing and supported on supporting insulators.

This design reduces the impact of short-circuit currents on the busduct system and minimizes the emission of electromagnetic fields.
Fitting the busduct with a dry-air overpressure system ensures its safe operation in the harshest environments, eliminating the danger of humid and polluted air entering into the busduct.

The busduct may be made with maintenance hatches or without them. The use of maintenance hatches allows for monitoring the condition of insulators and their possible replacement.

Individually designed supporting structures allow 12-30 metre spacing between them.

Delivery includes:

busduct,
tap-off busducts to auxiliary transformers, chokes,
connections to equipment (generator, transformers, generator circuit breaker, cabinets),
supporting structures,
transformer, lightning arrester and capacitor cabinets,
dry-air overpressure system,
High-voltage disconnectors.

Electrical parameters:

Conductor material: aluminium or copper,
Enclosure material: aluminium,
Nominal current: up to 7kA,
Nominal voltage: up to 36kV,
Short-circuit current: up to 250kA
Conformity to standards: ANSI, IEC.
Degree of protection: IP65.

Applications:

Main Generator Leads busducts for currents up to 7kA and voltage up to 36kV,
power distribution systems for industry and power engineering,
oil refinery and chemical plants,
Thermal power plants and heat plants,
hydroelectric power plants,
waste-to-energy power plants.

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