Household electrical circuits run between 110 and 120 volts, and dropping below this voltage occasionally damages an appliance. Motors depend on this voltage level to stay within operating parameters and can stall out if there is a voltage drop. This leads to potentially expensive repairs.
Some induction motors increase the current draw to maintain their power output in the event of a voltage drop. Because electrical wiring can only handle a set amount of current, exceeding this causes the appliance to burn out if not addressed. If planning a brownout, or drop in voltage, make sure to power off appliances beforehand.