| 摘要 |
PURPOSE:To attain the start of operation of a temperature fault monitor device at a level outside an upper/lower limit setting range, by supplying an abnormal signal to a stop control means only when the output signal given from a temperature monitor means is changed to an abnormal signal from a steady signal. CONSTITUTION:The temperature upper and lower limit detecting relays 3 and 4 deliver the steady signal to de-energize an upper/lower signal relay 6 when the temperature is within a set range and then the abnormal signal to energize the relay 6 when the temperature is outside said setting range respectively. When the temperature is lower then the lower limit in a start mode, the relay 6 is turned on to switch off a contact 6b. Then the conduction of a relay 9 is prevented. Therefore a contact 9a is kept off, and an alarm relay 8 does not conduct even though a contact 6a is switched on. When the temperature rises up to the upper/lower limit setting range, the contact 6b is turned on to actuate the relay 9. Then the contact 9a is turned on and the relay 9 is self-supported. The relay 8 conducts when the temperature gets out of the setting range. |
