Automatic surge suppressor disconnect protection system

Abstract

A surge suppressor disconnect protection circuit is coupled to a first surge suppressor. The first surge suppressor is electrically coupled to phase and neutral line terminals of an AC source to protect the first surge suppressor from predetermined overvoltages. The circuit includes a relay switch with a relay contact and a relay drive coil. The relay contact is setable to one of a high and a low impedance state. The relay contact is electrically connected to the first surge suppressor and to one of the line terminals. A signal adjuster is electrically connected at its phase port to the AC phase terminal and to the AC neutral terminal for rectifying AC to generate a DC signal. The adjuster filters the DC signal and scales the filtered DC signal. An amplifier is electrically coupled to the adjuster at a non-inverting input port and to a first voltage reference at an inverting input port. The amplifier output port is electrically coupled back to the inverting input port to provide a feedback path therebetween. An integrator displaying a predefined integrator time constant is electrically connected at its input port to the amplifier means such that a signal is generated at the integrator output port which is proportional to a length of time the scaled DC signal is greater than said first voltage reference. A non-inverting input of a comparator is electrically connected to the integrator output port, and an inverting port of the comparator is electrically connected to a second voltage reference. The comparator output is electrically coupled to the first end of the relay coil such that a current is provided to the relay coil which drives the contact to a high impedance state when the integrator output signal exceeds the second voltage reference.