Over-voltage protection and disconnect circuit apparatus and method

摘要

An apparatus and method for preventing the overheating and destruction of MOVs in an over-voltage protection circuit by providing an efficient circuit configuration, using a minimal number of components mounted in an efficient manner, to assure a rapid disconnect of the electrical power when designated MOVs begin to overheat. MOVs are incorporated in a way that provides capacity for dissipating very large transient over-voltage surges without increasing the number of thermal fuses needed for protection from overheating of the MOVs. A minimal number of thermal fuses are incorporated in such a way that a disconnection from the electrical supply is assured where necessary while the risk of acrid smoke and fire from overheated components is minimized. Thermal fuses having a relatively low opening temperature are installed using a method that avoids placing thermal stress on the fuses.