ROTATING GP-MOTOR 1908121 - 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
Certain generator sets equipped with rear mounted Masterpact 3000 amp and 4000 amp circuit breakers may be adversely affected when transported over harsh winter roads or storage in conditions leading to humidity moisture condensation on the breaker or the breaker bus bars. The entrained or condensing water may get inside the breaker through the arc stacks and damage the electronic equipment inside the breaker. The water/moisture may cause the internal CT sensor wires to corrode. Then the broken wires may act as antennas which pick up noise from the magnetic field generated by the voltage applied to the current path. The noise is then interpreted as “phantom current” by the breaker trip unit resulting in the erroneous current observed on the breaker metering display.Solution
If the generator sets equipped with Masterpact breakers are transported, stored, or exposed to harsh conditions remove the rear and side panels and inspect the breaker when the generator sets are received at the dealership or on the packager or customer site.
Illustration 1 g06168612
Illustration 2 g06168615Look for moisture signs, rust spots, or oxidation inside the terminal box (refer to the Illustration 1) and on top of the breaker arc stacks and bus bars (refer to the Illustration 2).If moisture is present or there are signs of corrosion, raise a Dealer Solutions Network (DSN) issue and consult with the factory to have the breaker inspected. If the damage is significant the breaker may need to be replaced, there are no field serviceable parts.