Summary of Fuse Testing for Barrel Module Fuse Boxes Duke University Jack Fowler

Fuse Box Production Summary Fuse Boxes have been in production for ~ 12 months 35 sets of each type are being produced This involves > 7500 fuses Fuses were delivered from Oct 03 until Aug 04

Fuse Box Production Steps Assemble Fuse Box components and solder Test Fuse Resistance Clean Fuse boxes and dry Dry fuse boxes for minimum 3 hrs at < 55° C Conformal coat fuse box components Final Test Boxes - continuity at < 100 V and check for breakdown at 2 kV Final assembly – add hardware and heat shrink and label cables

Fuse Boxes

Post Production Tests In January ’05 all fuse boxes were place under current for conditioning. After two weeks half of these fuse boxes were removed from current (Group A) and the remaining half remained under current until April ’05 (Group B). Each group contains ~3700 fuses. The following slides show the test set up and the results of the testing for each group.

Fuse Box Conditioning

Fuse Box Connections

Group A Test Results

Group B Test Results

Summary Before conditioning, fuse failures seemed to be stabilizing at ~ 0.1 % per week. Group A had 12 failures in 16 weeks or 0.75 fuses / week. Group B had 10 failures in 16 weeks or 0.625 fuses / week. Total failure was 22 fuses in 16 weeks or 1.375 fuses / week.