The aluminum terminal lugs should be crimped to aluminum  wire only. The tongue of the aluminum terminal lugs, or the  total number of tongues of aluminum terminal lugs when  stacked, should be sandwiched between two flat washers  when terminated on terminal studs. Spacers or washers  should not be used between the tongues of terminal lugs.  Special attention should be given to aluminum wire and cable  installations to guard against conditions that would result in  excessive voltage drop and high resistance at junctions that  may ultimately lead to failure of the junction. Examples of  such conditions are improper installation of terminals and  washers, improper torsion (torquing of nuts), and inadequate  terminal contact areas. Pre-insulated terminal lugs and splices must be installed using  a high-quality crimping tool. Such tools are provided with  positioners for the wire size and are adjusted for each wire  size. It is essential that the crimp depth be appropriate for  each wire size. If the crimp is too deep, it may break or cut  individual strands. If the crimp is not deep enough, it may not  be tight enough to retain the wire in the terminal or connector.  Crimps that are not tight enough are also susceptible to high  resistance due to corrosion buildup between the crimped  terminal and the wire.  [Figure 9-155] be replaced as soon as possible with permanent repairs.  Since some manufacturers prohibit splicing, the applicable  manufacturer’s instructions should always be consulted. Junction boxes are used for collecting, organizing, and  distributing circuits to the appropriate harnesses that are  attached to the equipment.  [Figure 9-157]  Junction boxes are  also used to conveniently house miscellaneous components,  such as relays and diodes. Junction boxes that are used in  high-temperature areas should be made of stainless steel. Hand, portable, and stationary power tools are available for  crimping terminal lugs. These tools crimp the barrel to the  conductor, and simultaneously form the insulation support  to the wire insulation.  [Figure 9-156] Broken wires can be repaired by means of crimped splices,  by using terminal lugs from which the tongue has been cut  off, or by soldering together and potting broken strands.  These repairs are applicable to copper wire. Damaged  aluminum wire must not be temporarily spliced. These  repairs are for temporary emergency use only and should Junction Boxes Crimping Tools Emergency Splicing Repairs Aluminum Wire Terminals Pre-Insulated Splices Figure 9-157.  Junction boxes.  Figure 9-155.  Terminal splices. Figure 9-156.  Crimping pliers.  9-92