Merlin Digital

dubai, United Arab Emirates

Any joint in an electric conductor is the weakest point, as far as the efficiency of current carrying is concerned, decided by the level and uniformity of contact pressure, the extent of the contact area, the joint resistance and ultimately the conductivity and thermal performance, and hence is given the maximum technical considerations in its design, in DELTABAR. DELTABAR joint are uniquely design with :- - Two numbers straight fish-plates, one on either side of each phase and neutral conductor - The fish plates having more cross sectional area than that of the conductor - More than usual overlap of fish plates with conductors - Phase segregation by high quality molded phase barriers 4 clamps, 4bolts steel clamping (external bolting). This ensures a thermally, electrically and mechani- cally proper and efficient joint design. The joints are covered by aluminium covers and the left over annular space are filled up by the same resin cast mix used in the feeder elements, thus making it life- time- maintenance free.

ELBOWS Elbows are standardized to dimensions of 482x482mm and are available in flat-wise & edge-wise types. Constructionally they are typical to feeder elements with projecting out conductors, suitable for standard joint connections. Unless unavoidable, flat wise elbows are not recom- mended, as they reduce the current-carrying efficiency of the system, due to 90o bending of the conductors, which results in broken conductor molecules. Typical Combination elbows - Offsets, Combination & Obtuse elements are designed, where critical site condi- tions does not allow connection of standard elbows. Also depending on project requirement, elbow joints can also be provided to cater to very short length elbow.

DELTABAR flanges are compact, with sealable metallic mounting body & hidden mounting provisions. The terminating conductor elements are tin-plated & holed for connection to switchgear termination.

Spring supports specially designed to support the weight of busways on each floor shall be provided as shown, for supporting vertical runs. The spring support assemblies are standardised for each Frame Size, accounting the largest weight of elements in each Frame Size. For horizontal applications, the busways are supported by threaded rods and hanger channels, where so preferred by our customers. The Standard arrangement of DELTABAR for horizontal runs, how ever in rigid Steel Frame Supports screwed on to Roof slab bottom.

Depending on load condition and the external environment, the conductors may have a tendency to contractexpand (Thermal expansion). Specially designed expansion joints are provided to suppress those effects. Expansion joints are recommended on every 40 m runs of straight conductor and also when the busway crosses the building expansion joints. These joints are normally designed for +-30mm length. Special designs are also available for up to +-90mm.

The feeder elements are of standardized design of 3.5m maximum length(shorter lengths are designed based on requirement), with the whole range up to 3200A being covered in two frame sizes - decided by two standardized enclosures one accommodating upto1600A with single conductor per phase(Frame size-1) and the other up to 3200A with two conductors per phase(Frame size-2), the width of the conductor standardized to 120mm in both frame sizes, their thickness varying from 3 to 7mm to cater to different current ratings. For ratings above 3200A and up to 6400A, DELTABAR design envisages use of two parallel runs of elements of frame size 2. Each bend-free phase and neutral conductor is individually color-sleeved using special, thermally & dielectrically high quality heat shrinkable sleeves and the conductors are spaced apart at a uniform gap of 10mm between the conductors

Transverse JointsBuilding Cross-over elements are provided , where the Busway crosses a building joint. The element will allow flexibility to the Busway Systems otherwise rigid & non-flexible Cast-Resin Busway, to accommodate the Non-uniform Building oscillation due to wind load. To ensure that the Transverse Element functions effectively, it shall be ensured that the Feeder Element crosses the Building only in a way that its conductor are oriented Vertically inside.

Unlike in the case of Power Distribution of cables, wherein, multiple cables run from the power source (incoming) to each load point or load centre, busway systems transfer power from the source (normally the LV panel Main distribution board) up to the last load point, with provision for tapping off power at the various load points along its way, through tap-off units and passes it on to the Sub-Main distribution boards of domestic, industrial or other load groups. Though each busway design, make or manufacturer evolves their own design of tap off units (both Bolted or Plug-in), plug-in Tap Off units are considered to be most ideal, as these can be plugged out for repair, when & if necessitated, even when the busway is live, retaining power without disturbing other load points. DELTABAR has evolved unique tap-off units, with standardized design & frame size, thereby ensuring utmost reliability and efficiency in power collection, irrespective of the magnitude of the current rating. i. The current carrying (collecting) parts on the tap off units are accommodated in a cast-resin tap-off moulding of two frame sizes, one to suit the Frame Size-1 feeder elements(5-bar) and the other for Frame Size- 2 elements(10-bar) ii. The female finger units of standardized design, one set catering up to 100250A and using multiples of the same as required for higher current ratings - 2 setsper phase up to 500A; 3 sets per phase up to 630A; 4 sets per phase up to 800A and 6 sets per phase up to 1250A. iii. This is made possible by standardizing the thickness of the mating male terminal thickness to 6mm, irrespective of the thickness of the main conductors of the feeder elements, of Frame Size-1 or Frame Size-2. Easiest method of hooking at the top, pushing-into-position and locking bottom by spring loaded pins is adopted for simplifying the mounting of even the 1250A rated heavier Tap-off Units. The Plug in units are designed such that earth mates first and breaks last ensuring safety. The feeder element with tap-off provisions are proven by type tests for IP68 protection rating, & the tap-off units are IP66 rated.