MIDWEST Field Services was at an educational facility in the Western United States performing inspections and testing of 15KV load break switches and indoor dry type transformers.  The services were being performed as part of an insurance claim.  The electrical distribution system had experienced a failure of some components within the system and the customer was having issues after replacing the damaged components and re-energizing the system.  Our services included but were not limited to performing hard-focused inspections, making minor adjustments to mechanisms, performing insulation resistance testing, contact resistance testing, and winding resistance testing.  No deficiencies were found with any of the equipment so all of the cover panels were installed and the equipment was energized.  It was at this time that the transformers secondary phase-to-phase and phase-to-ground voltages were measured and found to be fluctuating by as much as 50% below the expected voltage.  The equipment was shut down and the 15KV fuses for each of the load break switches were removed and the internal resistance was measured.  The manufacturer has a range for this fuse between 24.871 mΩ and 33.6 mΩ.  The fuses that were in service had resistance values that were nearly twice the manufacturer’s maximum tolerance.  These fuses were replaced with fuses that were within the manufacturer’s resistance tolerance and the equipment was again energized.  The secondary voltages for all of the transformers were again measured and found to be constant and within 1% of the nominal voltage.  One of the original 15KV fuses was opened up and found that the fusible link inside was connected by a small fragment of its original configuration.  The fuses were literally holding on by a thread inside which caused the increased internal resistance and translated into the erratic voltages seen on the secondary of the transformers.  Long story short, the entire electrical distribution system was exposed to the short circuit and while other components ultimately failed this event reinforced that the electrical stresses were experienced by the entire distribution system and caused other components (fuses in this instance) to be compromised to the point they were unacceptable for continued service.