Heat sensitive abnormal condition detecting and indicating device and method

摘要

A heat sensitive abnormal current condition detecting and indicating device associated with a watthour meter indicates that a possibly damaging surge has been experienced by the meter. The abnormal condition detecting and indicating device includes indicator means retained in normal position by a heat sensitive material, such as solder, with the indicator means being biased to move from the normal position to an abnormal condition position should the conductor being monitored experience a heat rise sufficient to soften the heat sensitive material and release the indicator means. A plurality of embodiments of the heat sensitive abnormal condition detecting and indicating device are shown including a rod maintained in normal position within a tube under spring bias with the rod being movable longitudinally to thereafter extend from the tube to indicate a possible abnormality when a monitored conductor experiences a heat rise sufficient to melt solder holding the rod in normal position, a flag mounted on a rotatable wheel and rod assembly maintained in a rotational normal position with a spring bias thereon so that the wheel and rod assembly rotates to a position wherein the flag indicates an abnormal condition when a monitored conductor experiences a heat rise sufficient to melt solder holding the wheel and rod assembly in normal position, and a spring arm held against the monitored conductor by means of solder so that a possibly damaging surge experienced sufficient to heat the conductor and melt the solder frees the spring load arm to spring outwardly for visually indicating that a possible abnormal condition has occurred.