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NEW - REPAIR - FABRICATION - DESIGN - MODIFICATION CURRENT-CARRYING MAST ARMS With CURRENT-CARRYING ARMS,
the arm body becomes the conductor between the cables and contact
pad and thus conventional bus tubes are eliminated. Regardless of
the design, current carrying arms are lighter in weight than conventional
mast arms and have decreased maintenance requirements due to the
exclusion of tubes, supports, structures and many insulated areas.
Both copper clad-steel and aluminum mast arms are repairable by a competent specialist. And while maintenance requirements are decreased, these arms do tend to accumulate sludge in much the same way as conventional arms. With this design it is particularly important to keep the internal chambers clean so the arms can be properly cooled... as excessive heating might cause problems to the dissimilar metals and weld seams. NEW FABRICATION
These Copper Clad-Steel arms, fabricated at Erie Copper Works’ plant, are made from a carbon steel plate with explosion-bonded copper cladding. Aluminum conductive arms are fabricated from flat or formed plates of a specific aluminum alloy. In addition to the required mechanical and structural properties, the aluminum alloy must have chemical properties, which impedes the corrosion sometimes caused by contact with water. The main advantage aluminum has over copper is its light weight and strength. The main disadvantage with aluminum compared to copper is the lower electrical conductivity. Alloy 5083 aluminum is about 30% IACS whereas deoxidized or OFHC coppers have electrical conductivities ranging between 94 and 100% IACS.
Click on here for information about Bus Systems |
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Last Update:
05/03/2005
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Electrically, hot arms reduce resistance and reactance in
the secondary circuit.
Plates are cut to size and welded together - steel
on the inside to form a water-tight box and copper on the outside
to make the entire outer surface a single, uniform conductor. Thus
the rectangular arm bodies are designed to perform all necessary
structural and electrical functions.