Aiming at the error tripping problem of leakage protector in electric energy information acquisition system domestically, this article discusses the principle of leakage protector and testing conditions of tripping. Then, the theoretic analysis and the experimental evaluation are both conducted from aspects of the impact of power line carrier communication and the anti-interference of leakage protector. The final result can be drawn that the tripping problem may be caused by the anti-interference itself, carrier signal characteristics, device insulation ability and power grid noises, etc. Thus, carrier signal is just one of main reasons leading to tripping problem, while better solution is to improve the design of leakage protector with enhanced anti-interference.