| 摘要 |
PURPOSE:To prevent explosion by performing forcible switching from recharge to floating(self-discharge prevention) automatically upon detection of overcharge or fault in a ventilation fan thereby stopping production of gas. CONSTITUTION:Upon detection of overcharge and fault in a ventilation fan, a forcible charge/floating switching section 3 performs forcible switching from recharge to floating and stops production of combustible gas. During automatic recharge operation, overcharge relay contact (cal) and a ventilation fan abnormal relay contact (fan) are connected with an existing automatic recharge as shown on the circuit diagram thus carrying out forcible switching from recharge to floating. In case of manual switching, the ventilation fan abnormal relay B contact is connected through terminals t15, t16 with a rectifier control circuit thus carrying out forcible switching from recharge to floating. By such arrangement, two main factors of explosion, i.e., mass production of combustible gas and permeation of combustible gas due to abnormality of ventilation fan, can be eliminated. |
