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 100/250A and using multiples of the same as required for higher current ratings - 2 sets\per 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.