Here is a setup I made similar to yours...
I have a separate box for the PID & RTD connection and the Power distribution.
I did it that way so I can use the smaller box as a digital thermometer.
I was willing to risk burning up a SSR to see if this would work. I used it a few times, but quickly progressed to a BCS controlled system.
I put a thermometer in the box and sealed it as best I could. Under 50% duty cycle running a 1680watt heatgun and a pump for 3 hours, the temp never exceeded 100f which is 37.8c. The operating range of the auber ssr is up to 70c.
There are NO fuses or over current protection in this build and the wiring is a rats nest.
I had no problems with it in probably 6-8 brews that it was used in. I still use the "Digital Thermometer" portion on occasion.