Square D has announced a product safety notice for AFI breakers manufactured between March 1, 2004 and September 23, 2004. The reason for this notice is that the arc interruption capability of these breakers MAY become inoperable due to the failure of an internal component in the electronic detection circuit. High ambient temperature and humidity levels can accelerate the possibility of failure. If this condition exists, the breaker will NOT properly detect or interrupt a high resistance low current arcing fault. Although short circuit and overload interruption ability remains, the AFI breaker will not do the job it was built for - arc fault interruption.