| 摘要 |
<p>The control system for gas escape warning and gas shutoff units uses a single sensor (1) to trigger both units and has a mains power supply (10). It also has a stand-by (9) which in the event of a mains failure is automatically switched (SW) to feed the shutoff unit (8) control equipment (6). When mains power is restored the switch reverses. Also, a delay switch (3) with a time constant of some seconds - pref. at least equal to the sensor reaction time (4-5 seconds) - is fitted in the line from sensor to shutoff unit, or both.</p> |
