do harm to

If you let go a snake or a scorpion,you’re guilty of doing harm to your companion.

见蛇见蝎,不打作。

Multiple reignition makes the frequency and amplitude of overvoltage increase and might do harm to transformer coils by cumulative effects for its surge steepness.

重燃使得电压频率和幅值均升高，会对变压器等绕组型设备绝造成危害。