How do you have the element mounted and wired? The reason I'm asking is that it is very possible that the problem is in the connections to the element.
An example: A friend had the same thing happen to him. His element was wired with crimp on terminal lugs between the wire ends and the element terminal block. This was all housed in an electrical box mounted to his keg. He got several brew sessions done and then ran into the same problem.
The end happenstance was that the crimp on lugs presented some resistance to the element current and over time this caused the connection to heat up. The more he use it the more it heated until the point of failure. When it failed, the wire/lug connection was burned through.
In his case, the solution was to restrip the end of the wire and reapply new terminal lugs - but - this time he also soldered (electrical solder) the lug/ wire connection. He's still brewing with it that way without issue. This happened several years ago - BTW.
You might want to take a look.
Edit for more thoughts: You might want to test the wiring with an ohm meter. This will help you locate the fault.
An example: A friend had the same thing happen to him. His element was wired with crimp on terminal lugs between the wire ends and the element terminal block. This was all housed in an electrical box mounted to his keg. He got several brew sessions done and then ran into the same problem.
The end happenstance was that the crimp on lugs presented some resistance to the element current and over time this caused the connection to heat up. The more he use it the more it heated until the point of failure. When it failed, the wire/lug connection was burned through.
In his case, the solution was to restrip the end of the wire and reapply new terminal lugs - but - this time he also soldered (electrical solder) the lug/ wire connection. He's still brewing with it that way without issue. This happened several years ago - BTW.
You might want to take a look.
Edit for more thoughts: You might want to test the wiring with an ohm meter. This will help you locate the fault.