SUBJECT: AFI Circuit Breakers, Type QO, QOB, HOM and Stab-lok manufactured between
March 1, 2004 and September 23, 2004
 Quote:
Schneider Electric Canada has become aware of a potential issue involving QO, QOB, HOM and Stablok AFI circuit breakers manufactured between March 1, 2004 and September 23, 2004. The arc interruption capability may become inoperable due to an internal component in the electronic detection circuit. High ambient temperature and humidity levels may accelerate this issue. If this condition exists, the breaker will not properly detect or interrupt a high resistance low current arcing fault. Short circuit and overload interruption capability continues to function properly.
Click >> Schneider Electric Notice (154k PDF file)

(Thanks to Tony Moscioni)