Problem
Under some circumstances the ground post can shear off below the level of the insert (see diagram above). This can be due to excessive torque, or dropping of the transformer with the post installed (they are shipped with the post in a plastic bag). We have been asked how to remove a broken post.
| Solution |
| There is a simple two step fix: |
| • |
Drill a 5/32“ (3,7 mm) hole in the middle of the broken stud (be careful not to go too deep). |
| • |
Drive in a “left hand spiral tapered flute” (a type of “screw extractor”), and remove the broken stud. |
Source of Screw Extractors
We tested this with the Gray Tool EX3 which is available from the John Windeler & Company (Toronto 416 675 6200), but they should be readily available at your preferred suppliers of tools or industrial supplies.
| Postscripts |
| • |
The fact that the stud can shear off from excessive torque is deliberate, since it can be replaced as described above. If the stud was too strong, excessive force could turn the insert and destroy the transformer itself. |
| • |
Our epoxy transformers, both leadless and with lead designs, had two ground insert locations. Some of you have asked why this was discontinued? The reason is that two would add unnecessary cost. In fact the only reason there were two on epoxy models was for manufacturing purposes – we used them to hang the transformer in the mold (a pour process). This is no longer necessary since we now use injection molding. |
|
