| 摘要 |
PROBLEM TO BE SOLVED: To provide a system for producing a semiconductor arranged such that when an over temperature preventive circuit detects over temperature of piping, that detection is held until an interlock circuit is reset and an alarm is generated continuously. SOLUTION: When an over temperature preventive circuit 10 detects an over temperature and the power supply to a piping heater 11 is interrupted, an over temperature detector also detects an over temperature and that detection is held until an interlock circuit 20 is reset. Even if the temperature of piping drops and the over temperature preventive circuit does not detect the over temperature, the interlock circuit holds the over temperature until it is reset. When the interlock circuit is utilized for generating an alarm, an alarm is delivered continuously and independently from operation of the over temperature preventive circuit until the interlock circuit is reset. Consequently, an operator can recognize an abnormality immediately to take an appropriate countermeasure.
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