National Instruments NI PXI-1050 User Manual

National Instruments NI PXI-1050 User Manual Manual pdf 32 page image

Chapter 3 MaintenanceNI PXI-1050 User Manual 3-4 ni.comSCXI Subsystem Fuse ReplacementPower Entry Module Fuse ReplacementCaution Disconnect all power before removing cover.Refer to Figure 1-3, Rear View of the PXI-1050 Chassis, as you completethe following steps to replace the power-entry module fuse:1. Power off the chassis.2. Remove the power cable from the power-entry module.3. Using a flathead screwdriver, pry the door to the voltage selectionwheel open from the top.4. Pull out the fuse drawer.5. Remove the fuse.6. Install the new fuse in the drawer.7. Reinsert the fuse drawer in the right side slot with the arrow pointingto the right.8. Close the door.9. Reinsert the power cable.SCXI Subsystem Backplane Fuse Replacement and CheckIn addition to the power entry module fuse, the analog supply lines on thebackplane are fused at 1.5 A. The fuse manufacturer is Littelfuse, partnumber 251 01.5.If you are going to make your own modules, fuse your module at 250 mAto avoid blowing the backplane fuses. Fusing your module also betterprotects your module because a failure can result in a large amount ofcurrent drawn, but not enough to blow the backplane fuses.The backplane fuses are located behind the SCXI subsystem fan.Complete the following steps to check or replace fuses:1. Remove the appropriate fan and filter from the rear of the chassis,following the instructions in the SCXI Subsystem Fan Filter Cleaningsection in this chapter. Make sure to power off the chassis and removethe power cable.2. The fuse marked with a copper + on the backplane is for the positiveanalog supply, and the fuse marked with a copper – is for the negative