Abstract: This concerns an undervoltage relay device for a circuit breaker system with a time delay feature. Two lines of the electrical system to be protected are monitored by a transformer. The output of which is rectified and provided to a capacitive element which, among other things, filters the signal. The capacitive element may comprise a single capacitor or combination of capacitors. The combination chosen is the function of the amount of time delay desired. If the voltage across the monitor lines drops below a predetermined value, the voltage level across the capacitive element begins to drop accordingly. This decreasing voltage signal is provided by way of a voltage divider to one input terminal of a comparator. The other input terminal of which is maintained at a reference voltage. When the signal voltage drops below the reference voltage, the comparator shift state thus causing an undervoltage relay coil to be deenergized.