We use sleeves made out of PVC for insulating sheet metal terminals. The operating temperature for these lugs is from 60 degrees C to 100 degrees C. For high temperature applications we can also provide Nylon or Polycarbonate insulating sleeves. For applications where there is a chance of the sleeve coming off due to vibrations (eg railway locomotive) we use a cooper sleeve under the PVC insulation, for the enhancing the rigidity.
As per international practice in use, Red colour is for terminals of 1.5 Sq.mm, Blue colour is for terminals of 2.5 Sq.mm & Yellow colour is for terminals of 4-6 Sq.mm,
Indian standard specifications are formulated for Aluminum terminals only. At present specifications for copper or sheet metal terminals are not formulated.
IS 8308 - 1993 covers Aluminum In Line Connectors & IS 8309 - 1993 covers Aluminum Tubular Terminal Ends. We however have obtained license for aluminum cable lugs Metal Socket only.
We have also developed lugs and connectors as per DIN specifications, however we don't have certification for the same.
We manufacture our copper lugs and connectors from cathodes obtained from LME approved warehouses only. Our aluminium lugs and connectors are manufactured from ISI certified tube manufacturers, who use aluminium ingots of the highest purity.
We have in-house testing facilities to check the conductivity for copper and aluminium.
No. Conductivity is affected by the type of impurities content in balance 1%. It has been observed that 0.5% arsenic may bring down the conductivity to the tune of 50% to 60%
Outer diameter of flexible wire is maximum compared to the other (stranded or solid} shape. Our terminals are designed to easily receive stranded wires. It becomes difficult to insert the flexible wire into the barrel. Best practice is to form the wire with forming dies or use one higher size of terminal (however that may cause flashing). Use of terminals having easy entry barrels will also provide ease of insertion.
Serrations help in cutting oxide film formed over the conductor. (In case of aluminium the oxide film is formed at normal temperature or humidity). Serrations also help in providing better grip of the joint. However, we have taken the pull off test over the same size of crimped terminal, with and without serrations. Though the terminals without serrations withstand lesser pull off load, it is will within the limits of 4Kg./Sq.mm. The use of a corrosion-inhibiting compound is a better option for breaking the oxide layer on the conductor.
It can be prevented or reduced by applying special corrosion inhibiting compounds between the surfaces of different material being used in electrical circuit.