| 摘要 |
The two signal monitoring channels are connected to the level monitoring electrode and, when the water level is below that predetermined by the electrode, provide an alarm. Using a relay (RE1,RE2) for each signal processing channel, the boiler installation is stopped by switching off the necessary voltage supply. Only after manual activation, can the accident protection be reset and the boiler installation restarted. The relay spring groups used to close/break the voltage feed are connected in series, and via a non-galvanic connection for each relay (RE1,RE2) are connected to an optical signal unit (LED1, LED2) applicable to each relay. A first optical siqnal unit (LED1) indicates when the actual contact spring groups in both relays assume a position corresp. to normal drive. Only the second optical signal unit (LED2) is activated when the contact spring groups in both relays adopt a position corresp. to the release of the protection unit, while a persistent signal indication from the optical units indicates that one of the monitored contact spring groups is not carrying out correct movement. |
