I have use these at two utilities...
The newer fused elbows have fewer problems associated with the EPR materials from which they were made than did those manufactured 10 or 15 years ago. The older materials didn't seem to allow you to separate the two halves of the elbow / fuse housing following a fuse opration. The heat energy generated from the fault current apparently caused the housing to get a little sticky. We find that those made more recently are far easier to separate after a fuse operation, partially due to the materials used in their manufacture and partially due to an improved formulation for the silicon lubricant used to assemble the two halves of the housing.
One caution concerning the design of the fused elbow that you will need to keep in mind during re-fusing efforts: If either the test point or the tester you use on the test point to verify that the cable is de-energized happens to fail, then you have no positive method of verifying that the cable is dead and grounded. (We use test points, but we also require live-line tests to verify that a circuit is de-energized.) One option is to spike the cable going into the bottom half-housing to verify that the fused elbow is completely de-energized. Another option (we chose this one) is to install the fused elbow on 5-foot jumper whose remote end terminates in the same vault in which the fused elbow terminates. This way, you have visual verification of isolation from the energized circuit prior to changing the fuse.
