Check this older post out, fan cooling is one protection, in-line fusible links in the motor leads are also a precaution worth the trouble. My tanks have fan cooling RX18 UNITS,these are also mounted using all-thread nuts.This and a large fan on the bottom with a smaller upper fan creates massive airflow,no heat can build up so the cooler mosfets handle the higher amps under a load.
If you replace the RX18,Phil @ RCTANKWARS in California had the fans and possibly unit ready equipped with the fan,but the real problem may still be another issue,what caused the over amperage?
http://www.rctankwarfare.co.uk/forums/v ... +RX#p74649" onclick="window.open(this.href);return false;