A bus duct is metal raceway the supports and contains a group of electrical bus bars. The duct comes in standard 10 foot lengths.
One of the greatest advantages of bus ducts is that they are capable of adding or removing a branch circuit without removing voltage from the whole duct.
Types of Bus Duct
Several types of Bus Ducts are used in different applications. In electrical engineering, isolated-phase bus (IPB), also known as Phase-isolated Bus (PIB) in some countries, is a method of construction for circuits carrying very large currents, typically between a generator and its step-up transformer in a steam or large hydroelectric power plant.
Each phase current is carried on a separate conductor, enclosed in a separate grounded metal housing. Conductors are usually hollow aluminum tubes or aluminum bars, supported within the housing on porcelain or polymer insulators. The metal housings are electrically connected so that induced current, nearly of the magnitude of the phase current, can flow through the housing, in the opposite direction from the phase current. The magnetic field produced by this current nearly exactly cancels the magnetic field produced by the phase current, so there is almost no external magnetic field produced. This also limits the amount of force produced between conductors during a short circuit. The external housings of the conductors remain at a low potential with respect to earth ground and are usually bonded to ground. Additionally, by enclosing the conductors in separate housings a high degree of protection from faults between the generator and the transformer is obtained. Since these conductors are between the generator and the first circuit breaker, if a fault were to occur the only way to interrupt it would be to stop the generator, which would take considerable time and result in much damage to the generator or conductors.
S.M.A.R.T. BUSDUCT / rising main system are made of high quality "F" class extruded epoxy insulation and available with copper and aluminum conductor. The design is compact and sandwiched with simple structure and easy joint systems. S.M.A.R.T. Busduct System has been established in the Indian markets since 2001 and is approved by the CRPI for 100kA short circuit rating and temperature rise test for both Aluminium and Copper conductors.
1 Horizontal angles are formed by bending.
2 Halogen-free plastic insulation.
3 The degree of protection by enclosure of the busbar
covers is IP30 and when fully sealed IP54. If required,
IP65 is also available. The installation adjustment range
is ± 40 mm. Busbar extension joints are enclosed,
otherwise the construction is open.
4 Vertical angles have the same enclosure class as busbar
joints. Installation adjustment range is ± 20 mm.
5 The busduct can be connected to the switchgear from
top or the bottom. Connection to ABB?s MNS type
switchgear is carried out using standard bushings
providing the same enclosure class as the busduct.
This guarantees the shortcircuit withstand of the busduct
system up to the main switching device terminals.