CYLINDER GP-LIFT 1752603 - Caterpillar

Test Overview
The purpose of this test is to determine if the drive motor stator windings have a short between a phase and ground, causing a ground fault. A ground fault severe enough may be detected using a multimeter resistance measurement between a conductor and frame ground. However, a less severe ground fault may not be detected with a multimeter. An insulation tester (megohmmeter) is required to determine if the problem exists in the insulation of the component. The following procedure details the usage of the insulation tester.In this test, the 300-8648 Insulation Tester Gp is used to test the conductors and the motor windings. Read the operating instructions for the tester and become familiar with the operation before use.Note: If the failure is a phase-to-phase short, it cannot be detected by an insulation resistance test unless the failure has progressed and shorted to ground. In this case, an inductance meter will be required. Refer to , "Troubleshooting, "Drive Motor Inductance - Test" in this manual.
The Power Train Electric Drive System will contain hazardous voltage levels during machine operation and for a period of time after machine shutdown.Do not remove any covers that will expose energized electrical components while the engine is operating. Do not remove any covers that will expose the energized electrical components while the components remain energized following an engine shutdown.Do not perform any type of electrical maintenance on the orange hazardous voltage conductors or the power train components while the engine is operating.Do not perform any type of electrical maintenance on the orange hazardous voltage conductors or the power train components while the components remain energized following an engine shutdown.Always perform the safe shutdown and de-energizing procedure before performing electrical service on the Power Train Electric Drive System.Failure to follow these instructions could result in personal injury or death.
In order to avoid the build up of hazardous live voltages on the exposed surfaces, all grounding wires must be properly connected at all times during engine operation.Any disconnected grounding wires (including the grounding bond wires, the conductor shield wires, the power inverter grounding straps and the component housing grounding straps) must be properly reconnected before the engine is started.Failure to follow these instructions could result in personal injury or death.
Test Preparation
Table 1
Test Preparation Values Results
1. Safe Shutdown Procedure
This procedure must be performed before service is performed in an area that is in the vicinity of Power Train hazardous voltage components and conductors to ensure that the DC power bus voltage has discharged properly.
Reference: Refer to the Troubleshooting, "Electrical Maintenance Guidelines" section of this manual. Perform the "Safe Shutdown Procedure for Electric Drive Wheel Loaders" before proceeding with this procedure. The Safe Shutdown Procedure for Electric Drive Wheel Loaders has been performed. DC voltage has been discharged to less than 50.0 VDC. OK: The Safe Shutdown Procedure for Electric Drive Wheel Loaders has been performed. The monitoring system display and the hazardous voltage indicator indicate that DC voltage is less than 50 VDC. The hazardous voltage