The busbar trunking systems shall be delivered and installed as design verified low-voltage switchgear and controlgear assemblies according to IEC/EN 61439-1 and -6, ready for connection.

The following descriptions are integral parts of the calculation and the contract. They must be considered in the descriptions of the individual systems and operational equipment, even if they are not mentioned in detail anymore.

The busbar trunking system must be suitable for power transmission, for example, between transformer and low-voltage main distribution, and for power distribution as an overall power supply both for horizontal and vertical installation.

The busbar trunking system must consist of standardized system components such as:

• Straight trunking units with and without tap-off points
• Feeder units for transformer, distribution board and cable infeeds
• Junction units with elbow, offset elbow, knee, offset knee, Z-units and T-units
• Tap-off units
• Accessories

• All straight trunking units must be available ex works in lengths up to max. 3m. Flexible junction units, and junction units as cable connections are not allowed.
• Expansion compensation units and fixed points shall be configured as required. The tap-off units and trunkings with tap-off points must achieve the degree of protection IP55 as minimum.
• Trunking units without tap-off points and without customer connections (only for feeder runs) must achieve the degree of protection IP66.
• The trunking units with tap-off points must be equipped with tap-off units as required. The position and number of tap-off points must be selectable.
• If necessary, it must be possible to provide the busbar trunking system with an asbestos-free fire barrier towards the wall or ceiling opening, certified according to EN 1366-3 and optionally conforming to the fire resistance classes EI90 or EI120 according to EN 13501 (formerly S90 and S120).
• If necessary, it must be possible to offer the busbar trunking system with the functional endurance classes E60 or E90 according to DIN 4102-12.
• The fire barrier for functional endurance must be mounted by the installer on site. The functional endurance certificate must be enclosed with the offer.
• The housing consists of aluminium painted in light grey (RAL 7035). Busbar trunking systems with housing made from pure sheet steel must have an additional PE-bar (earth bar) to ensure a high efficiency of the breaking capacity for low 1-pole short circuits.
• The individual system components must be connected by fitting a hook into a bolt, and tightening a state-of-the-art bolt-type terminal. The necessary torque of 50 Nm for the clamping connection must be indicated by the detachment of the outer part of the shear-off nut. The joint housing can only be closed when the shear-off nut has sheared-off after the tightening of the hook-bolt connection with 50 Nm.
• The degree of protection has to be IP 66 for the clamping connection.
• The busbars must be made of aluminium or copper, and be insulated along their entire length. The contacting surfaces are nickel-plated and tin-plated Aluminium resp. tin-plated Copper. The insulation material of the active conductors should be Polyester.
• The conductor cross-sections must not be below the values given in the technical data.
• For the supply of world-wide IEC market it must be possible to produce the busbar trunking system with identical features about the design, technical data and quality from different locations of production lines. Therefore these production lines of the busbar trunking system must follow identical processes and to an uniform quality management system from the manufacturer.