Can you sub-fuse inside the main COP? Isolate which part of the P24M is blowing. Do you have hardware cloth in the hoistway to keep the travel cable from hitting the spreaders or brackets? Had one that would pierce the travel cable jacket and then pull out as the car stopped eliminating the short, but I agree that it doesnt seem to be travel cable related. Will it blow on independent service? That would eliminate the lanterns. Disconnect the PIs to eliminate them?