Field Guide
Oshkosh JTP-4 Field Test
The following steps and video demonstrate how to field test a JTP-4 unit that is triggering an IGBT fault. Follow each step carefully before connecting the tester.
- Preparation: Power down the frequency converter and disconnect the input voltage source. Connect the IGBT Functionality Tester to a 120 VAC source.
- Disconnect the DC bus wires: Disconnect the negative DC bus wire 315 at both locations and remove the IGBT drive board for easier access. View the bus wire layout diagram. Next, remove the appropriate gate connections on the IGBT.
- Connect the IGBT Functionality Tester: Follow the printed diagram on the tester to connect the tester and the tester button to the correct terminals.