TERMI-FOIL terminals and splices make it possible for the transformer manufacturer to use aluminum foil or strip instead of copper wire windings. These terminations feature a calculated number of precision spaced lances which penetrate surface oxides and insulation, then imbed themselves in the foil or strip when the two faces are clamped together. This results in an airtight and moisture-proof connection, with no need for surface preparation or time-consuming termination equipment.
Terminations are reliable, light, economical and quickly accomplished. They dissipate heat efficiently and are mechanically strong. Tests in air and under oil show entirely satisfactory performance, in both elevated and sub zero temperatures, during current cycling and overload conditions.
TERMI-FOIL terminals are available in two types: wire to foil styles (for AWG wire Sizes 22 to 8 [0.3 to 8 mm²] and larger tap types (in lengths up to 15 in. [381 mm]) with provisions for lead terminations. Selection of the proper TERMI-FOIL terminal or splice depends on several factors:
- The terminal must have the same current-carrying capacity as the aluminum foil or strip (i.e., the CMA of the TERMI-FOIL terminal or splice must be equivalent to the CMA of the aluminum foil or strip). Use the nomograph or the following formula when selecting TERMI-FOIL terminals and splices. T x W x 1.273 x .62 = equivalent CMA of the TERMI-FOIL terminal or splice. T = thickness of aluminum strip or foil in mils. W = width of aluminum strip or foil in mils.
- The lanced area of the TERMI-FOIL terminal must cover a minimum of 60% of the width of the aluminum strip or foil to insure proper current distribution in the strip or foil.
- For TERMI-FOIL terminals with wire barrels, the current-carrying capacity of the wire used in conjunction with the terminal can be considered as the current- carrying capability of the connection.