PISTON ASSEM. 5J2531 - Caterpillar

Introduction
The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.Problem
Some units may experience insulation melting in some of the cables from the generator bus bars to the breaker bus bars or the extension bus bars. Insufficient torque in the cable lugs at the bus bar or improper cable crimp process in the cable lugs can cause a major difference in cable current per cable causing some of the cables to carry excessive load and fail.Solution
Do not operate or work on this product unless you have read and understood the instruction and warnings in the relevant Operation and Maintenance Manuals and relevant service literature. Failure to follow the instructions or heed the warnings could result in injury or death. Proper care is your responsibility.
If the problem is found on units rated at 4000 amps or less proceed as follows:
Replace all the cables in the affected phase bundle (6 or 8 cables per phase depending on the unit) even if only one cable failed. The melted cable is the one with the lowest electrical resistance path or the best cable in the bundle. The worst cable that caused the issue has sustained little or no damage and cannot be easily identified. For best practice, replace all the cables in the bundle. Torque the lugs to 100 20 N m.
Ensure that the cable lugs on the remaining non-affected phases are properly torqued to 100 20 N m.
If the problem is found on units rated at 4000 amps or more proceed as follows:
Replace all the cables in the affected phase (8 cables) and add 2 extra cables. Torque the lugs to 100 20 N m.
Add 2 more cables to the other phases and the neutral, ensure all the cable lugs are properly torque to 100 20 N m.Note: Due to the different locations of the holes in the bus bars there are different cable lengths and cable part numbers in the cable bundle. Measure the required cable length for the 2 extra cables from bus bar hole to bus bar hole. These cables may be currently available through the Caterpillar parts system. The new cable part number will have to be requested through CPI Feedback if this problem is found in the field. Request the Dealer TC to submit the information through CPI Feedback within the Service Information Management System (SIMSi). Reference CPI number 376710.